SIGMALT Load Banks

User Manual
Sigma LT Load Bank User Manual
Version 1.1 January 2018
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ASCO Froment Sigma LT load banks are manufactured in the UK by: 


© NJ Froment & Co. Ltd. This document may not be copied
or disclosed in whole or part without prior written authority.
 




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      

    

N J FROMENT  & COMPANYLIMITED,


     

Easton-on-the-Hill,
STAMFORD,
PE9 3NP,
United Kingdom
Tel: +44 (0)1780 480033
Fax: +44 (0)1780 480044
Web: www.froment.co.uk

© 2000-2018, N J Froment and Co Ltd (‘The Company’).

N J Froment and Co Ltd is part of the ASCO Power Technologies business platform.

Froment and the Froment logo are trademarks or registered trademarks of N J Froment and Co Ltd . All other names and logos referred to are trade names, trademarks or registered trademarks
of their respective owners.

While every precaution has been taken to ensure accuracy and completeness herein, N J Froment and Co Ltd assumes no responsibility, and disclaims all liability, for damages resulting from use
of this information or for any errors or omissions. Specifications are subject to change without notice.

The Company retains exclusive rights to the intellectual property in any designs, specifications, publications and software described or included herein. The property shall not be used in whole
or part for any purpose other than in connection with the Company’s particular products that this document is intended to accompany. The Company’s identification marks on its products and
documents must not be intentionally removed, concealed or defaced. This document may not be copied or disclosed, in whole or part, without prior written authority; any such authority will
include the condition that this copyright statement remains attached.
Table of Contents

Introduction

An important note on safety

Chapter One - Introducing Froment Load Banks

Why is Power Supply Testing Required? 1-2

• How can a generator be tested effectively?

• The load bank

Introducing Froment Load Banks 1 - 4

Froment Load Bank Control Options 1 - 5

• Sigma LT digital toggle switches

• Sigma LT hand-held
• How do load banks work

Load Bank Applications 1 - 6

• Generating set testing
• Testing UPS systems and batteries
• Data centre HVAC testing

Using Multiple Load Banks 1 - 8

Introducing Froment’s Sigma LT Load Banks 1-9

Sigma LT Load Bank Specifications 1 - 10

Chapter Two - Load Bank Setup

Using a Froment Load Bank Safely 2-2

Transporting Froment Load Banks 2 - 4

• Lifting by fork lift truck

• Protection and securing on transport

Setting up Froment Sigma LT Load Banks 2-6

• Location
• Setup in a plant room
• Inlet
• Outlet
• Wind effects
• Avoiding hot air re-circulation

ii
Table of Contents

Electrical Installation 2 - 8

• Voltage and frequency ratings

• External supply wiring - the fan and control power source
• Connectors
• Supply-on-test - general points
• Is a local isolator required
• Protective earth connection
• Making connections for single phase operation
• Single phase wiring

Control System Connections 2 - 11

Chapter Three - Digital Toggle Switch Control Operation

Before operating the load bank 3-2

• Safety warning

Turning the load bank on and off 3-3

Introduction to Sigma LT digital toggle switches 3-4

Sigma LT digital toggle switches - Quick start guide 3-5

Chapter Four - Hand-Held Control Operation

Introduction to the Sigma LT hand-held 4-2

• Why network load banks?

• The hand-held
• Symbols key

Sigma LT hand-held screens overview 4-4

Setup 4 - 5

Load Control 4 - 6

Load banks in a network 4-7

Data Logging 4 - 8

Settings 4 - 9

Status and Events 4 - 10

iii
Table of Contents

Chapter Five - Maintenance & Troubleshooting

Safety Warning 5 - 2

Routine Maintenance Procedures 5 - 3

• Daily (before each use)

• Monthly
• Annually

Fault Finding 5 - 4

Sigma LT Load Bank Status Display 5-5

Sigma LT Digital Toggle Switch - Error Messages 5-5

Sigma LT Hand-Held Status Display 5 - 6

Sigma LT Hand-Held - Error Messages 5-6

Appendices

3020 - Installation Diagrams A - 2

Certificate of Conformity A - 4

Electromagnetic Compatibility A - 5

Useful Equations A - 6

iv
Introduction
This manual should provide you with all the information that you need to safely setup and operate
Froment Sigma LT load banks.

The manual is divided into five chapters:

Chapter One provides an introduction to the general principles of power supply testing
and explains how a Froment load bank makes the process easier, safer and more reliable.
It then provides an introduction to Sigma LT load banks and its main features.

Chapter Two covers all of the procedures that need to be carried out before a load
bank can be put into operation. It explains how to transport and setup the unit safely
and then how to commission it to check that it will operate correctly.

Chapter Three provides an overview and instructions on correct operation of a Sigma

LT load bank using the digital toggle switches.

Chapter Four provides detailed instructions and reference for controlling a Sigma LT
load bank with the hand-held control.

Chapter Five covers the maintenance procedures you will need to follow to keep a
Sigma LT load bank operating correctly. It also explains how to troubleshoot should a
problem occur.

In addition to these five chapters there are a number of Appendices containing information that did
not fit easily within the main body of the text. These include installation drawings, a certificate of
conformity and some information about electromagnetic compatibility.
An Important Note on Safety
All Froment load banks are designed with safety as a very high priority, but their operation does
present some risks. In common with other test equipment, the safety of all concerned is dependent
on the way that the unit is operated. Do not use this equipment unless you have read and understood
this manual, and are familiar with the accepted practice for the industry. The equipment should not
be used by unskilled personnel. Misuse could result in serious injury and damage to the equipment.

Be sure to follow all of the safety warnings in this manual. In particular, pay careful attention to the
following points:

• Keep all personnel who are not directly involved with tests well away from the load bank and the
equipment under test.
• The discharge air can be very hot and could cause serious flesh burns. Do not touch the outlet
grille while the load bank is running, or for a few minutes afterwards.
• Ensure that there is no risk of the hot discharge air re-circulating back to the air inlet of the load
bank, extensive damage is possible due to short-circuiting the cooling air.
• Ensure the air inlet and outlets are completely unobstructed and that there is no loose paper,
plastic bags, or other debris that may be drawn on to the air inlet grille, obstructing the airflow.
• Combustible material left near the air discharge should be removed.
• Only operate the load bank with all the guards in place and with all of the covers and protective
screens securely in position.
• Make sure that all equipment is adequately grounded; this applies equally to the Supply-on-Test,
and the load bank.
• Ensure all cables are in good condition and adequately rated for the planned load, and that all
connections are securely made.
• Ensure all cables are long enough to lay in smooth curves, and are unstressed, undamaged, and
protected from mechanical damage. Lay the cables to minimise the risk of personnel tripping or
accidentally tugging on the cables.
• Do not switch off the cooling fan immediately after a test. Allow the fan to run for 3 minutes after
removing the load.
• Store the equipment in a clean, dry place when not in use. Only setup and operate the load bank
in environmental conditions suited to the enclosure classification of the load bank.
Chapter One
Introducing Froment Load Banks

If you are not familiar with the use of Froment Sigma LT load banks then you should start with this
chapter. It provides an introduction to the general principles of power supply testing and then it explains
how a Sigma LT load bank makes the process easier, safer and more reliable.

If you are an experienced load bank user you may want to skip the earlier sections, but you should
certainly read the introduction to Froment Sigma LT load banks which appears at the end of the chapter.
Chapter One

Why is Power Supply Testing Required?

There are many different ways of generating electrical power and many reasons why
generating equipment may be required. All of them have at least one thing in common: it
is essential that the generator be capable of operating effectively at its maximum rated
output when it is required.

Unfortunately, it is not so easy to be absolutely sure that this will be the case. Many
generating sets operate at a fraction of their rated output for a large proportion of the
time, and many others are intended to run in an emergency situation which may occur only
occasionally.

In both cases the only way to ensure that generating equipment is capable of providing
the performance required is to regularly test it whilst it is operating at its full rated output.

The various regulatory authorities and other concerned parties such as insurance
companies are aware of this, and the testing of new installations is mandatory. In many
cases there is also a requirement for regular testing for existing equipment, particularly
those that provide emergency or standby power supplies.

How can a generator be tested effectively?

The answer to this is very straightforward: apply a load that is equivalent to the generator’s
maximum output and then run the generator and observe how it performs.

The careful measurement of the generator’s output will reveal any problems with its ability
to meet the specification. Then, after repairs or modifications have been made, the test
can be repeated to verify that the fault has been rectified.

The load bank

For reliable testing it is important to provide a load that is suitably sized for the generator’s
output. It must provide a consistent and repeatable load so that the test can be accurately
measured and recorded and it must also be capable of dissipating the large amount of heat
that is generated during the test. And, it is critically important that the test does not put
the site load at risk.

To achieve all this requires a specialist item of equipment: the load bank. These consist
of an array of load elements combined with a control system designed to ensure that a
precise load can be applied in safety.

1-2
Introducing Froment Load Banks

How Do Load Banks Work?

Load banks are complex precision engineered machines, but to explain the general
principal we can provide a very simple model of how they work:

_ + _ +

A V

Figure 1-1 Basic DIY generator output test system.

Figure 1-1 shows the general arrangement of a very basic DIY generator testing system.
It’s simple, but it contains the four basic items necessary to test a generating set safely:

1. The fan heater’s heating elements provide an electrical load that is large enough to
ensure that the generator runs at full capacity.
2. The fan heater’s switch gear provides a control system that will ensure that the load
can be applied safely, and in a way that will not cause damage to the generator and its
control circuits, or injury to the personnel running the test.
3. The fan in the heater provides a method of safely dissipating the considerable amount
of heat generated by the test.
4. The voltmeter and ammeter provide instrumentation that will allow the results of the
test to be monitored.

Of course, this kind of arrangement can provide only a crude test for a low powered
generator and its ability to match the generator’s output accurately is very limited. As the
output of the generator increases, the cabling, switchgear and control equipment required
for this becomes increasingly heavier and more sophisticated. In addition, because of the
large amount of heat generated during testing, the issue of how to conduct the test safely
becomes increasingly significant.

1-3
Chapter One

Introducing Froment Load Banks

Froment load banks are purpose designed to provide all of the facilities needed to quickly,
safely and reliably test generating equipment with outputs up to several megawatts.

Load elements
Step 1 Step 2 Step n
Cold air Hot air
inlet Air duct
outlet
Fan
motor

Fan
contactor

Load
Sigma LT contactors
Digital Toggle
Switch Control Fuses
ASCO
R METERING
V/Hz/kW
!
Vx3 MODE

Ax3

5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW

LOAD
SELECT

LOCAL ON

3000 Series MASTER

LOAD
REMOTE

Current
External supply for Transformers
fan and controls

Supply-on-Test

Sigma LT
Hand-Held

Figure 1-2 Froment Sigma LT load bank core components

There are variations between different Froment Sigma LT load bank models, but Figure 1-2
shows a simplified schematic of the core components to be found in most units.

The diagram contains:

• An array of load elements grouped in small steps that are individually activated by
switchgear to allow the load applied to the generator to be precisely controlled.
• A fan and duct forced air system which ensures that the heat generated during testing
is vented safely to atmosphere.
• Fuses and safety interlocks that ensure that the test can be shut down in a controlled
fashion if any problems occur.
• Automatic precision control of the test and allow the results to be displayed with
better than 0.5% accuracy.

1-4
Introducing Froment Load Banks

Froment Load Bank Control Options

Reliable testing requires precise control of the load applied to the generator and accurate
real-time measurement of the generator’s output. To achieve this, Froment Sigma LT load
banks are fitted with a control panel and have the option of a hand-held control. Sigma LT
is a microprocessor-based control and instrumentation system specifically developed for
load bank applications.

Sigma LT Digital Toggle Switches

Sigma LT digital toggle switches are fitted as standard to all Sigma LT Load banks. Digital
toggles provide local, resistive only load testing with single and three phase instrumentation
on a seven segment display.

ASCO
R METERING

399 8 49 9 70 0
V/Hz/kW
!
Vx3 MODE

Ax3

5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW

LOAD
SELECT

LOCAL ON

3000 Series MASTER

LOAD
REMOTE

Sigma LT Hand-Held

The Sigma LT hand-held connects directly to the load bank to provide remote control and
enables up to 25 load banks to be connected into a single network.

1-5
Chapter One

Load Bank Applications

The main application for a load bank is usually generator testing. However, load banks are
versatile devices and they have a number of useful applications that can be applicable
including data centre Heating Ventilation Air Conditioning (HVAC) testing and UPS
testing.

Generating set testing

The specific tests that need to be carried out for a particular installation depend on local
regulations, the application, the type of equipment involved and the requirements of
insurance companies, local authorities and other interested parties.

Note: The specific The requirements for the testing of engine driven generators are described in ISO 8528
details regarding the part 6. This document explains the general test requirements and describes both a
frequency and type of functional test and an acceptance test. Functional tests must always be done and usually
test required may also occur at the manufacturer’s factory. Acceptance tests are optional and are often done on
be specified by local site, witnessed by the customer or his representative.
regulations or other
interested parties.
ISO 8528 part 5 defines three performance classes - G1, G2 and G3, each with different
criteria:

• G1 is the least stringent and applies to small generating sets intended to supply simple
loads.
• G2 is broadly equivalent to commercially available power.
• G3 is intended for sets which are powering loads which particularly require a stable
and accurate power supply.

A further class, G4, allows for performance criteria agreed between the supplier and the
buyer.

In addition to the testing that is carried out immediately after installation, it is important
to carry out regular tests as part of an ongoing maintenance program. This is particularly
important for emergency power supplies that may have long periods of non-operation.

The type of tests carried out include:

• Load duration tests (also known as a “heat run”), designed to record steady-state
voltages, frequency, and also to calibrate instrumentation and measure emissions and
fuel consumption.
• Load acceptance tests, which check changes in frequency and voltage regulation due
to sudden load changes. These tests ensure that the rise and fall of the generator’s
output voltage and frequency remain within limits as load is applied and removed.

1-6
Introducing Froment Load Banks

Testing UPS systems and batteries

Uninterruptable power supply systems consisting of a generating set combined with a set
of batteries are a common feature of data centres and other installations where maintaining
a constant power supply is critical. In the event of a power failure the batteries provide an
immediate source of power whilst the generator is automatically started, synchronised to
the correct frequency and put online.

Regular testing of the batteries, generator and its automatic control gear is extremely
important, but testing using the site load could put critical systems at risk and may not
provide sufficient load for a complete test. Load banks provide an ideal solution because
they will allow the operation of the UPS to be fully tested without posing any risk to the
site load.

Data centre HVAC testing

Heating, ventilation and air conditioning (HVAC) systems are vital in providing cooling to
server racks within data centres. The HVAC system must be able to maintain a constant
cool temperature when the servers are working at full capacity. Load banks are a cost
effective method of simulating heat produced by the servers. Operators can analyse how
the HVAC system copes with the temperature rise, without risking the vastly expensive
server racks over heating.

1-7
Chapter One

Using Multiple Load Banks

Froment’s Sigma LT control system allows up to 25 load banks to be interconnected and

controlled from a hand-held as if they were a single unit. This means that multiple load
banks can be combined to match particularly large generating sets.

Total control cable length = 250m

Sigma interface cable Load Bank Load Bank Load Bank

1 2 n

In Out In Out In
Sigma LT
Hand-Held

Supply
under
test

Figure 1-3 Connecting multiple load banks

Note: When multiple An example of a multiple connected load bank application is for an HVAC testing and
load banks of different verification in a data centre. The networked load banks produce heat discharge throughout
capacities are used the specifically selected areas in the data centre all controlled from a single Sigma LT hand-
load applied is shared
proportionally depend- held.
ing on the ratio of the
load banks’ capacity.
The cable sizes for the
Supply-on-Test must
take this into account.

1-8
Introducing Froment Load Banks

Introducing Froment’s Sigma LT load banks

Sigma LT load banks are resistive, portable and indoor load banks. Sigma LT load banks
can be controlled either locally or remotely. The load banks can be linked together in a
network to provide high capacity load tests with the functionality to control a specific load
bank in the network.

Froment Sigma LT load banks are manufactured with painted or powder coated mild steel,
folded and pop riveted together to form a monocoque construction. Load elements are
cooled by a direct airflow provided by an axial fan.

The input and output ducts are protected by stainless steel mesh screens. All of the
electrical and electronic components are housed behind painted or powder coated mild
steel panels with IP54 protection.

All Sigma LT units are designed to be moved by either built in castors or with a forklift.

For more information about other load banks that Froment can offer, please contact our
sales team.

1-9
Chapter One

Sigma LT Load Bank Specifications

3010 3020
Nominal capacity (kW) 110 200

Standard rated voltage (V) 400 400

Terminal qty / phase & size (mm) Single pole Single pole

Length (mm) 973 1140

Width (mm) 733 870

Height on base (mm) 950 950

Weight, approximate (kg) 150 220

Fan(s) - no. x diameter (mm)* 1 x 450 1 x 560

Fan & control current (A) 8 10

Airflow direction Horizontal Horizontal

* 50 Hz fans only

       

Control Panel Power Terminal

 Compartment 

Hot air exhaust

 
Air Intake

 Switchgear 
Compartment

 

External Inlet

 
Forklift Pockets
Twist Lock
Connectors

Figure 1-4 Froment Sigma LT 3020  © NJ Froment & Co. Ltd. This document may not be copied
 

or disclosed in whole or part without prior written authority.

    
      

     
       

1 - 10
Chapter Two
Load Bank Setup

This chapter covers all of the procedures that need to be carried out before a Froment Sigma LT load
bank can be put into operation. It explains how to setup the unit safely and how to check that it will
operate correctly.

Important!
The chapter contains a number of important safety instructions. Do not attempt to setup or operate
the load bank until you have read and understood this chapter. Misuse could result in serious injury and
damage to the equipment.
Chapter Two

Using a Froment Load Bank Safely

Your safety, and the safety of those around you, is dependent on your knowledge of this
equipment’s safe operating procedures. Load banks can be dangerous and must not be
used by unskilled personnel, or by those who have not familiarized themselves with these
instructions.

You should remain alert to potential danger during transport and setup, when the unit is in
operation, and when maintenance operations are performed.

There are four main sources of danger:

Handling hazards. Load banks are large, heavy devices and they often have to be
manoeuvred in to tight, difficult spaces before they can be setup.

Contact with high voltage electricity. Serious injury or death could result from contact
with electrically live parts. Even though the connections to the load bank may be temporary,
they must always be made to the same standards as if they were permanent.

Contact with fast moving parts. The fan, in particular, can cause serious injury if you
come into contact with it when it is in operation.

Heat hazards. When a test is in progress the resistive elements can glow cherry red. The
heat they produce is removed by the air that the fan forces past them, but that air in turn
can become very hot.

To avoid these hazards, pay particular attention to the following points:

• Make use of the correct handling equipment and ensure that all personnel involved
in transportation and setup have the appropriate training and experience needed to
carry out the operation safely.
• Only operate the load bank with the covers and protective screens securely in position.
• Make sure that both the Supply-on-Test and the load bank are adequately grounded.
• Ensure all cables are in good condition and adequately rated for the planned load, and
that all connections are securely made.
• Ensure all cables are long enough to lay in smooth curves, and are unstressed,
undamaged, and protected from mechanical damage.
• Lay the cables to minimise the risk of personnel tripping or accidentally tugging on
the cables.
• Keep all personnel who are not directly involved with tests well away from the load
bank and the equipment under test.

2-2
Load Bank Setup

• The discharge air from the load bank can cause serious burns. Keep away from the
outlet grille while the load bank is running, and do not touch it for at least 10 minutes
after the test is completed.
• Do not switch off the cooling fans immediately on concluding a test. After removing
the load allow the fans to run for a further 3 minutes to dissipate the residual heat. This
will reduce any fire risk and prevent possible damage to the equipment.
• Make sure that the air inlet and outlets are completely unobstructed and that there is
no loose material that could be drawn in to the air inlet grille.
• Ensure that there are no combustible material near the air discharge.
• Keep an approved electrical fire extinguisher present at all times when the load bank
is in operation.

2-3
 Chapter Two

Transporting Froment Load Banks

Froment Sigma LT load banks will vary in weight depending on the model. Make sure you
check the load bank name plate for the correct weight. Sigma LT load banks have fork lift
pockets and/or castors. Only lift from the forklift pockets and no where else.

Lifting by forklift truck

Check the specifications to ensure that the forklift truck has sufficient capacity to safely
Warning! Avoid walking lift the weight. Add 5% to the specified weight for minimum packing, and 15% for a unit in
on the roof of the unit. an export wooden case.

Protection and securing on transport

If a load bank is carried on an open goods vehicle, it should be covered with a tarpaulin, or
a similar to stop the wind from driving the fan.

Use the forklift pockets to

tie down the load bank

Castor mounted load banks

should be supported off of the
castors during transport. Use
wooden blocks for this purpose.

Note: Do not tie straps

over the top of the load
bank. The tie-down Figure 2-1 Castor-mounted load banks should be supported off the castors and firmly fixed
should be made through down
the pockets in the fork-
lift pocket base only.

2-4
Load Bank Setup

Setting up Froment Sigma LT Load Banks

There are a number of factors that need to be considered before you select a load bank
for a particular application. Obviously it is important to ensure that the load bank has
sufficient electrical capacity to test the supply, but you also need to ensure that it can
operate correctly and safely in the position you have chosen.

Location
The first thing to decide when setting up a load bank is where the unit is to be located. You
need to consider the following to ensure that the unit can be operated safely:
Environment. Sigma LT load banks are designed for indoor use only. A standard Sigma
LT load bank can be used in an ambient temperature between -10°C and +40°C, at 90%
relative humidity (non condensing), and at altitudes up to 1000m above sea level.

Loading. The load bank is heavy and must be setup on a level surface that is capable of
supporting its weight (see nameplate).

Space. There must be sufficient space to provide access for maintenance to all of the
panels and the protective inlet and outlet grilles. There must be at least one metre of clear
space on the air intake side of the load bank (the fan side) and five metres of clear space
on the air outlet side. See the appendices of this manual for the specific requirements of
individual units.

Airflow requirements. When it is operating a Sigma LT load bank can require up to 10 m3

of cooling air per second. As it passes through the unit, the air becomes hot enough to
Note: If necessary, provide a risk of fire or personal injury.
a barrier should be
When setting up the unit you need to make sure that there is adequate air available, that
erected around the hot
air outlet to prevent any it can be discharged safely, and that there is no risk that the hot air will recirculate to the
possibility of personal air intake of the unit.
injury.

2-5
Chapter Two

Setup in a plant room

If the load bank is setup in a plant room you will need to pay particular attention to the
airflow requirements of the unit. The temperature of the surrounding air must not rise
above the maximum rated ambient temperature of the load bank (40°C is standard) and
steps should be taken to prevent re-circulation of the discharge air.

You must take into account the requirements of any other equipment (heating plant,
generating sets, compressors, or another load bank) that may also require a supply of
cooling air. In these cases the total air requirement of all the plant must be added together
to arrive at the required fresh airflow.

The air inlet and air outlet of the load bank must be in the same room, or space.

Inlet

The free area of any inlet grille or opening into the plant room should be at least twice
the area of the load bank air outlet. If other plant in the same plant room requires air,
then the size should be such that the maximum air inlet velocity is below 3m/sec. This
should ensure that the depression within the plant room would always be less than 10Pa,
relative to the outside environment. The distance from the fan inlet to a blank face of a
wall or panel, square to the fan centre line, should be not less than 1m, or one fan diameter,
whichever is the greater.

Attenuators incorporated in the plant room inlet grilles should be sized for a maximum
pressure drop of 10Pa.

Outlet

The outlet opening must have a total free area of twice that of the load bank air outlet, plus
whatever is required for any additional plant.

Wind effects

The load bank must be protected from the effects of the wind, which in some circumstances
could defeat the fan. The inlet and outlet grilles or louvres should preferably be on the
same side of the building. The effect of natural wind is then cancelled out, regardless of
its direction. Other arrangements need careful attention, combined with detailed site and
local knowledge to ensure satisfactory operation in all expected weather conditions.

2-6
Load Bank Setup

Avoiding hot air re-circulation

To reduce the risk of hot air re-circulation place air inlets at low level and air outlets at high
level. If this is not possible the inlets and outlets should be spaced well apart. Inlet and
outlet louvres on the same level should have a clear space between them of at least three
times the width of the largest opening. Strategically placed barriers and screens can help
to separate the two air-streams.

Careful consideration should be given to the likely effect of nearby buildings, walls or even
parked vehicles, which could seriously disrupt the free escape of hot air, and result in hot
air re-circulation.

Other nearby air handling plant can also interfere with the airflow to, or from, the load bank.
Equipment should be spaced well apart and positioned so that their airflows complement
each other rather than compete.

When multiple load banks are being used it is important to ensure that the hot air from one
load bank does not exhaust directly or indirectly on to any other load bank.

Packaging

Before starting setup remove all packaging. Dispose of it in the appropriate way.

2-7
Chapter Two

Electrical Installation

The electrical installation for a load bank consists of making connections both for the
Supply-on-Test and for an external supply that is used to power the load bank’s fans and
control system.

Note: The Load Bank The requirements for the two supplies are described separately here, but the following
supply cables must be
protected by a Short
general points apply in both cases:
Circuit Protective
Device (SCPD), which • The work must be carried out by a person with the appropriate training, qualifications
is suitably rated to the and experience.
capacity of the supply • All cables should be appropriately rated and installed in accordance with current
cables.
standards and accepted practice.
• The cables for the supply must be sized appropriately and properly fitted terminals
must be used.

Voltage and frequency ratings

Ensure the external supply rating matches the voltage and frequency of the control circuit.

Exceeding the voltage ratings or supplying the wrong frequency can cause damage to the
load bank so please check the plate carefully before setup.

Figure 2-2 Consult the load bank’s name plate for voltage and current ratings
before making connections

2-8
Load Bank Setup

External supply wiring - the fan and controls power source

Refer to the load bank’s rating plate for the external power supply requirements. The
supply must be capable of supplying the fan motor starting current, and must be fused
accordingly. Load banks designed to be movable are fitted with an external power input
plug on the outside of the load bank.

Figure 2-3 16A single phase, external power inlet for the fan and control circuit

The load bank is supplied with a 16A external cable coupler. Refer to figure 2-4 for correct
wiring configuration.

L
3 N

2P+E 2P+E
(Side on view) (Front on view)

Figure 2-4 16A single phase external cable coupler

Connectors
The load bank is fitted with 400A, single pole PowerLock connectors to allow quick
connection and disconnection of the cables.

L1 L2 L3 PE

Figure 2-5 400A, Single pole PowerLock connectors

2-9
Chapter Two

Supply-on-Test wiring - general points

• It is good practice to route the three phase conductors in a close tre-foil layout, held
together with cable-ties. This minimises stray magnetic fields from the cable array, and
reduces inductive losses in the cables. In the event of a high fault current flowing this
arrangement minimises the risk of sudden and violent cable movements.
• If the connections are made using more than one conductor for each phase connection
all the cables on any one phase should be of exactly the same length, and laid along
a similar route. Ensure that the three phase conductors are equally shared between
multiple cable entry openings, to minimise eddy current losses.
• The load bank supply cables must be protected by the short circuit protective device
(SCPD) which is suitably rated to the capacity of the supply cables.

Is a local isolator required?

When planning the installation consider if a local isolator switch is required. If the output
circuit breaker of the Supply-on-Test is easily accessible, then this can perform the
isolating function.

Protective earth connection

An earth conductor must always be bonded to the frame of the Supply-on-Test and
connected to the grounding terminal of the load bank (marked PE).

Making connections for single-phase operation

3-phase load banks can be used for testing single-phase supplies. The method of
connection (and the load available) will vary depending on the rating of the load bank, the
supply voltage and frequency. Refer to chapter 4 for more information about changing
between single and three phase testing.

Single phase wiring

Single-phase operation is achieved by connection between two phase terminals, one of
which is used as neutral.
Note: If the load bank
is fitted with a 3-phase A-C connection mode. The A-C connection mode shown in Figure 2-6 will give
fan motor, an external
3-phase mains input will
approximately 50% loading capacity when the nominal load bank supply voltage is
be required for the con- connected or 17% loading capacity when a single-phase (√3) equivalent supply is used.
trols and fan supply.

L1 L (Live)

L3 N (Neutral)

Figure 2-6 A-C connection for a single phase supply

2 - 10
Load Bank Setup

The maximum permissible single-phase supply voltage for this connection is 100% of the
3-phase load bank rated voltage.

AB-C connection mode. The AB-C connection mode shown in Figure 2-7 will give
approximately 66% loading capacity when the nominal load bank supply voltage is
connected or 22% loading capacity when a single-phase (√3) equivalent supply is used.

L1 L (Live)

L2

L3 N (Neutral)

Figure 2-7 AB-C connection for a single phase supply

The maximum permissible single-phase supply voltage for this connection is 86% of the
3-phase load bank rated voltage.

Control System Connections

Sigma LT load banks all have digital toggle local controls on the load bank. Alternatively
connect the hand-held to the upper connection socket for remote control of the load bank
and to control multiple load banks in a network.

Sigma LT hand-held
connection socket

Figure 2-8 The Sigma LT control cable connector.

2 - 11
Chapter Three
Digital Toggle Switch Control Operation

This chapter explains the local digital toggle switch operation of Froment Sigma LT load banks. It
describes the functions of the various buttons and displays. For troubleshooting and error message see
chapter 5.
Digital toggle switch control operation

Before Operating the Load Bank

Ensure that:

• The load bank has been setup according to the instructions and safety warnings in
Chapter Two.
• The external supply (for fans and controls) is connected according to the instructions
in Chapter Two.
• The supply under test is connected according to the instructions in Chapter Two.

Safety warning

Do not attempt to operate the load until you have read and understood this manual. Misuse
could result in serious injury and damage to the equipment.

• Keep all personnel who are not directly involved with testing the supply well away from
the load bank and from the equipment under test.
• The discharge air can be very hot and can cause serious burns. Do not touch the outlet
grille while the load bank is running, or for a few minutes afterwards.
• Only operate the load bank with all the guards in place and with all of the covers and
protective screens securely in position.
• Ensure that there is no risk of the hot discharge air re-circulating back to the air inlet
of the load bank, extensive damage is possible due to re-circulating the cooling air.
• Ensure that there is no loose paper, plastic bags, or other debris that could be drawn
in to the air inlet, or any combustible material left within range of the air discharge.
• After removing the load at the end of a test allow the fan to run for three minutes to
dissipate the residual heat.

3-2
Chapter Three

Turning the load bank on and off

The load bank provides a method of quickly starting and shutting down the load bank:

The Fan and Controls Supply Isolator. This is a two position switch which isolates the
Warning! Operating power supply to the fan and controls when it is in the off switch. It can be used to perform
the Fan and Controls an emergency stop, but it can also be padlocked in the off position and this means it can
Supply Isolator or Stop be used to secure the load bank fromWarning!
unauthorised operation.
Isolator for fan Fan and
Button does not isolate and controls supply only.
Internal
the Supply-on-Test
from the load bank
wiring. Some of circuits
within the load bank will
remain live.

Other supplies may enter this load

bank. Isolate all before working on
this equipment.
Figure 3-1 The Fan and Controls Supply Isolator

3-3
Digital toggle switch control operation

Introduction to Sigma LT Digital Toggle Switches

The Sigma LT digital toggles are fitted as standard to all Sigma LT load banks. The control
panel is for local control only and instrumentation is displayed on the seven segment
digital display.

Error Warning Lamp Metering Display Load Select Mode

ASCO
R METERING
V/Hz/kW

480 0 59 9 70 0
!
Vx3 MODE

Ax3

5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW

LOAD
SELECT

LOCAL ON

3000 Series MASTER

LOAD
REMOTE

Local/Remote Master Load

Control Selection

Figure 3-2 Sigma LT digital toggle control panel

Warning! The Fan and MODE. The mode button has three functions.
Controls Supply Isolator
does not isolate the 1. Press mode to cycle through the different instrumentation displays: 3 phase
main power wiring from
Voltage and Currents or Voltage, Frequency and Power. The LED will illuminate of
the Supply-on-Test.
Some of the circuits the instrumentation selected. (Please note cycling through instrumentation is only
within the load bank available in 3 phase mode).
will remain live when 2. Press and hold mode for 4 seconds to select single phase (1ph A-C | Conn 1ph
the switch is in the off a-C or 1ph AB-C | Conn 1ph a-bC) and three phase (3ph ABC | Conn 3ph abC)
position.
connections. Leave for 5 seconds to select. Ensure the connection mode selected
matches the power connection wiring.
3. Press mode to acknowledge an error if displayed.

LOAD SELECT. The load select buttons have two functions.

1. Press and hold at power up to set the load limit. See figure 3-3. Please note the load
limit selected will be saved.

3-4
Chapter Three

Version
ASCO
R METERING
V/Hz/kW
!
Vx3 MODE

Ax3

Model 5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW

LOAD
SELECT

LOCALO N

3000 Series MASTER

LOAD
REMOTE

Load Limit
(kW)

25% 50% 75% 100%

Figure 3-3 Load limit buttons with load limit amounts.

2. Press any combination of the load select switches to choose the required load in kW.
LED’s will illuminate of those selected. If 30kW is required, press 5kW, 5kW, 10kW and
10kW. Then press master load on. Alternatively if master load is already on there will
be a one second delay then load will be applied automatically. The one second delay
allows a synchronous load change.

MASTER LOAD. Master load applies any load selected when turned on and rejects all load
when turned off. The master load LED will illuminate when on and extinguish when off.

LOCAL/REMOTE CONTROL SELECTION. Switch between local and remote control.

Selected control will be indicated by the illuminated LED. Remote control mode is only
available when a Sigma LT hand-held is connected. Control will automatically switch to the
hand-held when connected.

ERROR WARNING LAMPS. LED lamp will illuminate if an error occurs, the error type will
appear on the metering display. Press mode to acknowledge the error.

Sigma LT Digital Toggle Switches - Quick Start

1. Connect the load bank to a power source and the supply on test (see chapter 2).
2. Turn the fan and controls supply isolator on.
3. Turn the master load switch on. The master load LED will illuminate. If load is applied,
press master load to immediately reject all load on test.
4. Press any combination of the load select switches to choose the required load in kW.
For example, If 30kW is required, press 5kW, 5kW, 10kW and 10kW. Then press master
load on. Alternatively if master load is already on there will be a 1 second delay then
load will be applied automatically.
5. Repeat step 4 to change the load i.e. if the load required is now 20kW press one of the
10kW switches to deselect and after a one second delay 20kW of load is applied. The
one second delay provides a synchronous load change.
6. Press mode to cycle through the instrumentation types.
7. Press master load to reject all load on test.

3-5
Chapter Four
Hand-Held Control Operation

This chapter explains the optional hand-held operation of Froment Sigma LT load banks. It describes
the functions of the setup, buttons and displays. For digital toggle switch operation see chapter 3 and
for troubleshooting and for error messages see chapter 5.
Chapter Four

Introduction to the Sigma LT Hand-Held

The Sigma LT hand-held is an optional method of control for networking load banks. Up
to 25 Sigma LT load banks are able to be connected in a single network. Sigma LT also
provides individual control of any load bank in the network.

Why network load banks?

• Networking allows remote control of the load bank from up to 250m.

• Smaller load banks can be networked for increased capacity, perfect for testing where
a larger load bank would not be suitable i.e. basements and roofs.
• Finer load resolution can be achieved by networking a load bank with small load steps
with larger load banks.
• Redundancy can be achieved by using n+1 load banks. This can be important when
running 24 hour commissioning tests.

The Hand-held

Aluminium
Enclosure

USB Port
4.3” Touch
Screen Display

Cable connection point

Figure 4 -1 The Sigma LT Hand-held

4-2
Hand-held control operation

Key

See below for the list of symbols that will need to be used for operation of the hand-held
control.

Load Selection Navigation

Decrease Load Next Screen

Increase Load Down Screen

Manual Load Entry Back Screen

OK Network Overview

Apply Load Network Search

Reject Load Settings

Status - Load Off

Other Symbols
Status - Load On
Load Bank ID

USB Found Status - Load Warning

Status - Error

Single Load Bank

Control

4-3
 Chapter Four

Sigma LT Hand-Held Screens Overview

The hand-held has a number of screens for various functions. Below lists the main screen
types with arrows showing the button and navigation flow.

Load Bank Search/Start Up Screen Main Load Bank(S) Control/Status Main Load Bank(S) Instrumentation Screen

10 Digit Load Selection Screen Network Overview Screen Settings Screen

Status Screen Individual Load Bank Control/Status Settings Screen 2

Events Screen Individual Load Bank Instrumentation Screen

4-4
Hand-held control operation

Set Up

LCL200 Rev 1 LCL200 Rev 1 LCL200 Rev 1

ASCO ASCO ASCO

R METERING R METERING R METERING
V/Hz/kW V/Hz/kW V/Hz/kW

                 

! ! !
Vx3 MODE Vx3 MODE Vx3 MODE
Ax3 Ax3 Ax3

5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW 5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW 5 kW 5 kW 10 kW 10 kW 25 kW 50 kW 50 kW 50 kW

LOAD LOAD LOAD

SELECT SELECT SELECT

LOCAL ON LOCAL ON LOCAL ON

3000 Series MASTER

LOAD
3000 Series MASTER
LOAD
3000 Series MASTER
LOAD
REMOTE REMOTE REMOTE

Figure 4-2 Sigma LT network cable connection configuration

Note: In the settings
menu match the
• Connect load banks to supply on test (see chapter 2).
working voltage to your
supply on test. This will • Using the network cable, connect the hand-held to the first load bank in the upper
ensure the correct load socket.
is applied. • Connect other load banks by using a second network cable from the lower socket to
the upper socket of the next load bank (repeat as necessary).
• The load bank metering display will automatically turn on when powered.
• The hand-held will first search for load banks. New load banks will be automatically
added to the network as they are discovered.
• The hand-held will display the supply instrumentation and load control screen ready
for load to be applied.

4-5
Chapter Four

Load Control

Figure 4-3 Load selection screen options

Note: Load increases

and decreases by Voltage, Current, Power and Frequency are shown in the frame at the top of the screen.
the minimum load
resolution in the Press Next Screen button to display full 3-phase instrumentation.
network.

Select Load (load values in kW)

• Select Load using increase load and decrease load buttons.
• Alternatively press on the manual entry to open the keypad and type in the
new load selected and press OK.

Apply and Reject Load

• Apply load by pressing apply load button . Applied load will be shared between
the load banks on the network according to the load bank size and minimum load
resolution.
• The load change is synchronised across all load banks.
• The hand-held instrumentation will display the accumulated power and current from all
load banks on the network.
• The status button on the bottom left will turn green as a sign that load is
applied.
• The load banks will now be in remote mode, and a blue remote light will be illuminated on
the load bank control panels.
• To reject all load on test press the reject load button .

4-6
Hand-held control operation

Load Banks in a Network

Load bank ID
Figure 4-4 Load bank networking screens

With more than one load bank in a network, it may be useful to see an overview of the
load banks connected and individually control each one.

• From the main instrumentation screen, press the Network Overview button . The
screen will show load measured in kW as a total on the network and for each load bank.
• The Network Overview will summarise the load measured and the load available on the
whole network and for each individual load bank.
• Load banks will be added to the network in the background if they are discovered,
however the Network Search button will refresh the search if required.
• Press a load bank to view instrumentation and control it individually.
• The load bank ID is displayed on the bottom line and the blue remote lamp will
flash on that load bank. In this way you can identify which load bank you are controlling.
• Load control from this screen will be specific to this particular load bank*.
Note: The first load • Press Down Screen to move to the next load bank or press Network Overview
bank turned on will
have the ID #1 the to go back and view all load banks in the network.
second #2 and so on. • Use load control (page 4-6) to apply and reject load.
Utilise this feature
to map out the load
banks as required. *Load applied to the entire network will override individually assigned load on a specific
load bank.

4-7
Chapter Four

Data Logging

Figure 4-5 A USB symbol will appear when connected and will blink when logging is active

• Instrumentation data logging is available when a USB flash drive is connected to

the hand-held. A USB symbol will appear in the top right corner of the main
screen to show it has been found.
• Data logging will automatically start when load is applied to all load banks in the
network. The USB symbol will blink when writing data to the USB.
• Reject load on all load banks in the network to stop data logging. Do not remove USB
when load is applied.
• A tabular separated file is created with the file name ddhhmmss.txt. This contains 3
Voltages, 3 Currents and Frequency of every second in the test.
• The data can be opened in spreadsheet software for further analysis.

Firmware upgrades
• To upgrade the firmware in either the hand-held or the load bank connect USB
device containing the upgrade files. This process will upgrade all of the load banks
in the network. Contact our support team for more information about the latest
firmware files.

4-8
Hand-held control operation

Settings

Figure 4-6 Hand-held settings screens

• From the main screen, press Settings.

Working Voltage
• Setting the working Voltage will recalculate the load capacity allowing the correct
load to be applied at the set voltage. As default the hand-held will be set at the nomi-
nal voltage of the load bank.
Connection Mode
• Select the connection mode required. Three phase is the default setting.
Network Time and Date
• Press the next screen button . Network Time and Date will synchronise the
time stamp in all of the networked load banks. Network time and date is important for
correct data logging.
Language
• Select from various languages in the language menu.

4-9
Chapter Four

Status & Events

Figure 4-7 The status and event screens

• If an error occurs on the load bank, an error message will be

displayed on screen.
• Pressing the screen will acknowledge the error, and the load bank will be removed
from the network until it is operating correctly.
• From the main screens, press to access load bank status. Load
bank status LEDs will visually show the load bank status to quickly show any errors.
• Press next screen to display the load bank and hand-held event history. This
will be updated as new events occur. This feature is also available for individual load
banks in the network.

4 - 10
Chapter Five
Maintenance & Troubleshooting

This chapter describes both the routine maintenance procedures needed to keep Froment Sigma LT
load banks operating correctly and the procedures you may need to troubleshoot the equipment if you
run in to a problem using it.
Chapter Five

Safety Warning

Maintenance work should be undertaken only by qualified personnel who are fully aware
of the danger involved and who have taken adequate safety precautions.

Always isolate all the supplies to the equipment before inspecting, moving equipment,
removing or replacing parts.

Work on the equipment while the electrical supplies are connected is not normally
necessary. If it should become necessary for any reason, take extreme care not to come in
to contact with live parts.

You should remain alert at all times when the unit is in operation. There are three main
sources of danger:

Electricity can kill. Serious injury or death could result from contact with electrically live
parts. Even though the connections to the load bank may be temporary, they must always
be made to the same standards as if they were permanent.

Load banks contain fast moving parts. The fan, in particular, can cause serious injury if
you come into contact with it when it is in operation.

Load banks produce a lot of heat. When a test is in progress the resistive element can
glow cherry red. The heat they produce is removed by the air that the fan forces past them,
but that air in turn can become very hot.

5-2
Maintenance & Troubleshooting

Routine Maintenance Procedures

To keep the load bank in good working order, carry out the following maintenance tasks at
the specified intervals:

Daily (after transportation or before each use of the load bank):

• Inspect the equipment for signs of damage.

• Ensure that the inlet and outlet grilles are free from dirt, debris or obstruction. Remove
the grilles and clean them if necessary.
• Check that both the external supply and the Supply-on-Test are properly connected.
• Check that the connecting cables are free from damage.
• Check that all cables are secured and routed so that they do not present a safety
hazard.
• Ensure all panels are secure.

Monthly

• Clean and inspect painted surfaces for damage or corrosion and touch up as necessary.
• Check that there is no build up of dirt or debris on the load elements.
• Check that the fan rotates freely.
• Isolate the supply and then inspect the resistive load element terminals, ensuring that
Warning! The fan can
they are tight and show no signs of overheating.
cause serious injury
when it is in operation. • Visually inspect the switchgear cabinets, wiring, fuses and contactors for signs of
Ensure that the supply overheating.
is isolated before re-
moving safety covers.
• Visually inspect and clean all filters.

In addition, carry out a load check to ensure that load contactors and elements are
operating correctly:

1. Connect a supply (at the load bank’s rated voltage) to the load bank.
2. Set and apply loads at 30%, 60%, and 100%, and make a note of the power value shown
on the instrumentation (or external metering).
3. Check that the power values are within 5% of the load set on the controller.

Note: The recommend- Annually

ed interval for a calibra-
tion check is one year, Verify the load bank instrumentation’s calibration. If adjustment is required contact
unless the equipment
has been subject to Froment for advice.
misuse or damage.

5-3
Chapter Five

Fault Finding

The following chart covers some of the typical faults you might encounter and some
possible solutions.

Fault Possible Causes Possible Solutions

Cooling fan does not start or run No load applied • The cooling fan may not run until load
is applied. Apply the load and verify
that the fan starts.
No power to fan • Check that the Fan and Controls
Supply Isolator is turned on.
• Confirm that the control supply fuse is
not blown.
Fan thermal overload tripped • Check that the fan is not obstructed
and that it is free to rotate.
• Check the motor current and overload
setting.
No load is being applied Supply-on-test is not switched on. • Confirm that the Supply-on-Test
circuit breaker is switched on.
• If fitted, ensure that the load bank
circuit breaker(s) is switched on.
Load bank over temperature trip • Allow the load bank to cool and reset
over temperature trip.
• Check that the airflow through load
bank is unobstructed.
• Check for any signs of hot air re
circulation.
Faulty or damaged connecting lead • Check that the hand-held lead and
connectors are not damaged. Use
local operation for testing.
Incorrect or wrong load is applied Supply-on-test voltage • Ensure the working voltage and
connection settings are correct.
Excessive volt drop • Check rating of cables.
• Check generator AVR droop settings.
Single phase operation or phase missing • When testing a single phase
generator, check the method of
connection in the hand-held or digital
toggle switch control settings.
• For three phase operation verify that
all of the phases are present.
Loading problem • Check the load fuses.
• Check the load contactors.
• Check the load elements.

5-4
Maintenance & Troubleshooting

Sigma LT Load Bank Status Display

The load bank status is displayed on the seven segment LED located on the Sigma LT front
control panel.

Figure 5-1 The Sigma LT digital toggle switch panel LED display

Sigma LT Digital Toggle Switches - Error Messages

Error Type Display Possible Causes

Communications Loss (transmit error) err Conn t • Unplugged cable from load bank to hand-held
• Damaged cable
Communications Loss (receive error) err Conn r • Unplugged cable from load bank to hand-held
• Damaged cable
Over Voltage err OUer UoLt • Voltage applied is too high for the load bank

Low airflow (if fitted) err AIr FAIL • Check that the fan is not obstructed and that it is free to
rotate.
Motor Overload err FAn OUEr • Check that the fan is not obstructed and that it is free to
rotate.
• Check the motor current and overload setting.
Over Temperature “1” err OUER TC 1 • Allow the load bank to cool and reset over temperature
trip.
• Check that the airflow through load bank is unobstructed.
• Check for any signs of hot air re circulation.
• Check all fans and filters on the load bank are
unobstructed
Supply line error err SPLY LInE • Error in supply connection, check wiring according to
single phase connection mode
Internal Software Error err SoFt FaIL • Software fault. Please contact our support team.

Firmware update required Info UPd sys • Firmware update required in either the hand-held, SIGMA
gateway or PC system.

5-5
Chapter Five

Sigma LT Hand-Held Display

As well as the Sigma LT digital toggle display messages and errors will also appear on the
hand-held. The hand-held will show load bank specific and overall network messages.

Note: When the hand-

held is connected,
errors will display on
the hand-held only and
not on the digital toggle
control panel.

Figure 5-2 The Sigma LT Hand-held error display

Sigma LT Hand-held - Error Messages

Error Type Display Possible Causes
Communications Loss Comms failure • Unplugged cable from load bank to hand-held.
• Damaged cable.
Wrong Voltage (if dual voltage is fitted) Wrong voltage • Voltage applied is too high for selected voltage - ensure
voltage is correct.
Over Voltage Over voltage • Voltage applied is too high for the load bank.

Low airflow (if fitted) Air fail • Check that the fan is not obstructed and that it is free to
rotate.
Motor Overload Motor Overload • Check that the fan is not obstructed and that it is free to
rotate.
• Check the motor current and overload setting.
Over Temperature “1” Over temp failure • Allow the load bank to cool and reset over temperature
trip.
• Check that the airflow through load bank is unobstructed.
• Check for any signs of hot air re circulation.
• Check all fans and filters on the load bank are
unobstructed.
Supply line error Supply line error • Error in supply connection, check wiring according to
single phase connection mode.

5-6
Maintenance & Troubleshooting

Error Type Display Possible Causes

Data logging file open failure Log open failed • USB flash drive corrupted or unreadable.
• USB port damaged.
• Unplugged USB.
Data logging file write failure Log write failed • USB flash drive corrupted or unreadable.
• USB port damaged.
• Unplugged USB.
Internal Software Error Comms failure • Software fault. Please contact our support team.

Other Messages
Display Possible Causes
Network search Network search • Searching network for load banks

Load bank detected Load bank detected • New load bank has been found in the network

5-7
Appendices

The following pages contain additional information that may be useful but does not easily fit in with the
rest of the text. This includes a specification for each of the Froment Sigma LT load banks and a number
of diagrams that show dimensions and space requirements for each unit.
 Appendices

3020 - Installation Diagrams

    



 






 











Figure A-1 3020 front view and side view

   


 
 








 
   


   




  





 Figure A-2 3020 back and side views 
 


A-2 
    
  


Appendices




3020 - Installation Diagrams 












 
   


Figure A-3 3020 plan view

   







 



   

A-3
 Appendices

3010 - Installation Diagrams

    


 






 










Figure A-1 3010 front view and side view 

 
    


  

   




   







 



 Figure A-2 3010 back and side views 
 
 
 

    
A-4
 
Appendices




3010
 - Installation Diagrams


 



   




   

Figure A-3 3010 plan view






   

A-5
Appendices

EU Declaration of Conformity
Certificate of Conformity

Product: Load Bank

Name of Manufacturer: N J Froment & Company Limited,

Easton-on-the-Hill, STAMFORD, PE9 3NP,
United Kingdom
Telephone +44 (0)1780 480033
e-mail admin@froment.co.uk
Website www.froment.co.uk

Country of Origin United Kingdom

This declaration of conformity is issued under our sole responsibility of the manufacturer
Object of Declaration: Load Bank Types: 3000 Series
6000 Series
8000 Series

The object of the declaration described above is in conformity with the relevant Union
harmonisation legislation:
2006/42/EC Machinery Directive
2004/108/EC Electromagnetic Compatibility Directive
2014/35/EU Low Voltage Directive

References to the relevant harmonised standards used or references to the other technical
specifications in relation to which conformity is declared:
EN60204-1:2006+A1:2009 Safety of Machinery. Electrical Equipment of Machines.
EN 61000-6-3:2001 Electromagnetic Compatibility. Generic Emission Standard.
EN 61000-6-2:2001 Electromagnetic Compatibility. Generic Immunity Standard.

Basis of self attestation: Quality Assurance to BS EN ISO 9001:2008

Registered Firm Certification No: FM 38927

Signed for and behalf of: N J Froment & Company Limited

Place of Issue: Easton-on-the-Hill, STAMFORD, UK
Date of Issue: 1st June 2017
Name & Position: J.W. Barratt Managing Director
Signature:

One copy of this declaration accompanies each load bank,

for customer retention

A-6
Appendices

Electromagnetic Compatibility

This equipment has been designed and constructed to comply with the European
Community Directive 89/336/EEC. To ensure that the requirements of the Directive and
related standards are satisfied it is essential that the equipment is used as intended and in
full accordance with the operating instructions.

Immunity to external interference (EN 61000: Part 6)

• This equipment will not suffer permanent damage, or become dangerous or unsafe as
a result of electromagnetic interference at the levels set in the standards. Normally it
will continue to operate as intended. Electrostatic discharges or breaks in the power
supply may cause the equipment to shut down until it is manually re-set and re-started.
• Exposure to higher levels of electromagnetic disturbance, above the prescribed limits
(for example by the operation of a hand-held transmitter close to the remote controller)
may result in out-of-tolerance readings on the instrumentation.

Electromagnetic emissions (EN 61000: Part 6)

• Electromagnetic disturbances generated by this equipment do not exceed the

prescribed levels that could cause interference to radio, telecommunications or
television reception apparatus. There will be no interference provided the reception
equipment itself is constructed and used in accordance with the applicable standards,
and its antenna is located more than 10 metres away.
• If highly susceptible apparatus is used nearby, particularly if its faulty operation could
cause danger, then you must take additional measures to minimise the risks.
• This test equipment is intended to cause controlled changes in the load on an electrical
power supply. Such tests may result in disturbances in the Supply-on-Test that are
outside prescribed limits. If susceptible apparatus is connected to the Supply-on-Test,
particularly if its faulty operation could cause danger, then it should be switched off, or
disconnected, during the tests.

A-7
Appendices

Useful Equations

Apparent Power (kVA)

kVA = kW 2 + kVAr 2
V ×I× 3
kVA =
1000
kW
kVA =
pf
kVAr
kVA =
1 − pf 2

Resistive Power (kW)

kW = kVA × pf
V × I × pf × 3
kW =
1000
kW = kVA2 − kVAr 2

Reactive Power (kVAr)

kVAr = kVA × 1 − pf 2
V × I × 1 − pf 2 × 3
kVAr =
1000
kVAr = kVA2 − kW 2

Power Factor (pf)

kW
pf = cos φ =
kVA

Current (A)
kVA × 1000
I=
V× 3
kW × 1000
I=
V × pf × 3

De-rate from Nominal Voltage and Frequency

2
 V 
kW =   × kWnom
 Vnom 
2
 V  Fnom
kVAr =   × × kVArnom
 Vnom  F

Note: All voltages are phase-to-phase values and assume a 3-phase system.

A-8
 ASCO Power Technologies - Froment Load Banks
Cliffe Road
Easton-on-the-Hill
Stamford
United Kingdon
Tel: +44 (0) 1780 480033
froment.sales@ascopower.com

www.ascopower.com www.froment.co.uk

The ASCO and ASCO Power Technologies marks are owned by Emerson Electric Co. or its affiliates and utilized herein under license. ©2018 ASCO Power Technologies. All Rights Reserved. Publication No. 5039 v1.1

ASCO. Innovative Solutions.