T-Line

Generator Control, Protection and Monitoring

» Control. Monitor. Protect.

SELCO T-Line
The SELCO T-line offers a complete range of system components for generator control, protection and power monitoring.

The units are for DIN rail mounting or screw mounting in switchboards. Since the units are working on identical principles
and have similar design and adjustment schemes, they are easily installed or replaced. All units are available in a number of
versions varying in supply voltage and other functions, hence meeting specific customer requirements to a large extend.

Synchronizing and load/power control

The SELCO T-Line range includes various Auto Synchronizers and Load Sharers for load/power control. The Auto Synchronizers
perform automatic synchronization of incoming generators in a minimum of time. The Load Sharers provide automatic load sharing
and system frequency control for generators running in parallel.

Two solutions are available: One for synchronizing and load sharing on generators with conventional governors (and electronic
speed controllers via an intermediate motorized potentiometer). The other for connection directly to all types of electronic speed
controllers. For synchronizing SELCO also supplies Synchroscopes for illuminated indication of the phase difference.

Also available is a VAr Load Sharer for automatic load sharing of the reactive power or for power factor control on generators
running in parallel with the grid (utility).

Cogeneration Application

Grid
T4500

M8100

Busbar
T4500 B9300 T4500

T4800 T4800

G G

Synchronizing Parallel Running Generators to the Grid or a Shaft Generator

T4000 Auto Synchronizer T4500 Auto Synchronizer
When applied with the B9300 Power Re­
ference Unit, one or several generators
can be operated in parallel with the grid.

T4900 VAr Load Sharer

The T4000 performs automatic synchro- The T4500 performs automatic synchro-
nizing of an incoming generator with elec- nization of an incoming generator in a
tronic speed controllers in a minimum of minimum of time by controlling the fre-
time, by controlling the generator speed quency via the electric servomotor on a
and the phase between the generator speed governor or via the E7800 Moto-
and the busbar. rized Potentiometer, or T7900 Electronic
The T4900 provides automatic reactive
Potentiometer.
load sharing (VAr) and system voltage
The unit has fixed and variable output for
control for parallel running generators.
adaptation to a wide range of electronic Among the features it can control the
speed controllers. T4800 Load Sharer to e.g. transfer a load
The reactive load and voltage are mea-
from one or several diesel generators
sured on each generator, compared with
operating in parallel with the grid, or on
T4400 Load Sharer board a ship, to a shaft generator.
the other generators and corrected via
the E7800 Motorized Potentiometer or
The frequency will be aligned by the syn-
T7900 Electronic Potentiometer, until
chronizer through the load sharers. The
balance is obtained. The T4900 can also
unit has voltage matching output with
be used for power factor (Cos Φ) control
adjustable voltage window.
in parallel operation with the grid. One
unit is required for each generator.
T4800 Load Sharer
T5000 Paralleling Relay
The T4400 is a load sharer for generators
with electronic speed controllers. It in-
cludes a built-in frequency control and an
integration function, providing a very high
overall stability and compensate for any
drift within the engine speed controller.

A soft load/unload function is also pro- The T4800 provides automatic load
The T5000 can be used as a synchro­
vided. When activated, the T4400 will sharing and system frequency control of
nizing aid or as a check synchronizer. It
slowly increase or decrease speed to generators running in parallel. The load
will give a closing signal to the generator
transfer load to or from the generator. on each generator is compared with the
circuit breaker when voltage difference,
A built-in relay can automatically trip the load of the other generators and adjusted
phase difference and frequency differ-
circuit breaker when unload is completed. via the electric servomotor on the speed
ence are within safe limits, thus prevent-
governor or a motorized poten­tiometer
ing da-mage or disturbance to the power
The T4400 has a built-in reverse power until balance is obtained.
plant.
protection with selectable limit and time
delay. One load sharing unit T4400 is An unloading function is built into the
required for each diesel generator in par- unit to facilitate smooth transfer of the E7800 Motorized Potentiometer
allel operation. The load sharers are inter- load from a generator before being taken
connected with a 2-wire cable. out of service, by an automatic tripping MOTORIZED
POTENTIOMETER
signal to the breaker. E 7800

When applied with the B9300 Power

Reference Unit, one or several generators The unit also has reverse power protec- 40
50
60

can be operated in parallel with the grid. tion. One T4800 unit is required for each 30 70

diesel generator in parallel operation. 20 80

More T4800 units interconnected with a 10 90

2-wire cable. 0 100

The E7800 Motorized Potentiome- INSULATION BLACKOUT LOAD DEPENDING MASTER TIME PO
MONITORING MONITORING START & STOP CONTROL REFE
ter can also be used as an individual
stand-alone unit for many industrial
applications.

Available for AC or DC supply with

the DC versions being equipped with
ALARM ALARM
a step motor for adjustable speed. INDICATION INDICATION
Flush mounted unit with standard
measurements of 96 x 96 x 75mm.
REVERSE POWER REVERSE POWER
EXCITATION LOSS EXCITATION LOSS
M8100 Synchroscope
OVERCURRENT OVERCURRENT
SYNCHROSCOPE

TOO TOO
SLOW FAST
SYNC SHORT CIRCUIT SHORT CIRCUIT

TACHO SYNCHRONIZING TACHO SYNCHRONIZING

ENGINE ENGINE
BUS GEN LOAD SHARING LOAD SHARING
CONTROLLER CONTROLLER

The M8100 provides illuminated VAr LOAD VAr LOAD

SHARING SHARING
indication of the actual phase differ-
ence between generator voltage and
MOTOR MOTOR
GOVERNOR GOVERNOR
busbar voltage. POTENTIOMETER POTENTIOMETER

When obtaining phase accordance, AVR AVR

the two green LEDs at 12 o’clock will

in-dicate and the generator circuit
breaker can be closed.

The unit can be supplied with an

optional integrated paralleling relay.
Typical equipment applied for three diesel generators and one shaft generator

Flush mounted unit with standard

measurements of 96 x 96 x 80mm.
The unit determines the power to be increase and decrease contacts and a device
B9300 Power Reference supplied from the generators to the grid, requiring control / adjustment by a voltage or
adjustable 0-100%. current signal, such as an electronic speed
Unit
controller.
Flush mounted unit with standard In such applications, the T7900 acts similar to a
measurements of 96 x 96 x 75mm. motorized p ­ otentiometer, only the output can be
POWER REF. UNIT
B9300 a voltage, a current or a pulse width modulated
signal (PWM), while the ­motorized potentiometer
T7900 Electronic
has a resistor output.
Potentiometer
ON Basic configuration is easily done by standard
dials and dip switches while advanced configura-
0 10 tion is accessible by PC. The PC configuration is
done by a standard ANSI terminal in clear text.
The T7900 can also be used as a programmable
The B9300 is applied in connection power reference unit (like the SELCO B9300).
with SELCO Load Sharers T4400 and The power reference facility provides program-
T4800, when running in parallel with mable in­crease/decrease ramps as well as eight
the grid (utility). pre-programmable target settings.
The T7900 Electronic Potentiometer is A 0 - 10 VDC output is also provided for remote
typically used as an interface between indication of the output level (0-100 %).
OWER
ERENCE
FREQUENCY
MONITORING
VOLTAGE
MONITORING
POWER
MONITORING
FREQUENCY
DEVIATION
T2000 Reverse Power Relay

ALARM ALARM
INDICATION INDICATION

REVERSE POWER REVERSE POWER

The T2000 will, during parallel operation,
EXCITATION LOSS EXCITATION LOSS prevent the generator from running as a
motor, thus protecting the prime mover
OVERCURRENT OVERCURRENT
e.g. a diesel engine and unloading the
remaining generators by tripping the
SHORT CIRCUIT SHORT CIRCUIT generator breaker.

TACHO SYNCHRONIZING SYNCHRONIZING

T2100 Excitation Loss Relay

ENGINE
LOAD SHARING
CONTROLLER

VAr LOAD VAr LOAD

SHARING SHARING
φ

MOTOR MOTOR
GOVERNOR
POTENTIOMETER POTENTIOMETER

AVR AVR
The T2100 protects against partial or
complete excitation loss on the syn-
chronous generator. If a generator under
parallel operation has a low excitation, a
high inductive current is running into the
generator.
This current is detected and the faulty
generator breaker is tripped, thus avoid-
ing overload on the other generators
with a possible blackout of the system.

Generator protection and T2200 3 Phase Overcurrent

Relay
power monitoring
The SELCO T-line range also includes a wide selection of protection relays and
units for monitoring of the bus-bar and generator voltage, frequency and insula-
tion, as well as detection of blackout.

The trip levels and the delays before trip are easily adjustable using dials at the front
cover. Some units also furnish an adjustable hysteresis setting.
The T2200 has a broad application,
where all 3 phases or any single phase
current detection will function as protec-
tion, control or monitoring.
The relay detects the highest of the 3
input currents and, when the preset val-
ue is exceeded, an output relay will be
­activated after a preset time delay.
 The relay detects the highest of the 3
Complete Protection of Generators
input currents and, when the preset
values are exceeded the output relays
will be activated after preset time delays.

T2500 3 Phase Overcurrent

and Short Circuit Relay

The T2500 is intended for protection of

generators, power transmissions and con-
sumer supply against thermal ­damage and
GENERATOR’S PERMITTED faults caused by high currents, with con-
AREA OF OPERATION
sequent tripping of the system breaker.
This figure illustrates the complete protection of a generator. The green shaded The relay detects the highest of the 3
area illustrates the permitted area of operation for a generator. This information input currents and, when the preset
is normally supplied by the generator manufacturer. values are exceeded, the output relay will
be activated after preset time delays.
The vertical axis represents the active power, and the horizontal axis represents
the reactive power. The active power is represented by I x Cos Φ. The T2700
•

Power Relay measures I x Cos Φ, and when it becomes too high, the relay will trip,
T2600 Dual Current Relay
indicated by the upper horizontal red line.

The Reverse Power relay measures -I x Cos Φ, representing the active power in the
negative direction, and it will trip for reverse power. The T2100 Excitation Loss
Relay measures -I x Sin Φ, representing the reactive power in negative direction,
and it will trip when exceeding the level represented by the red vertical line.

T2300 3 Phase Short Circuit T2400 3 Phase Dual

Relay Overcurrent Relay The T2600 determines load depending
start and stop levels of a standby diesel
generator. When load increases on the
running diesel generators more than e.g.
90%, adjustable, for a preset time, a start
signal to call for the standby diesel gene­
rator will be provided. If the load decrea­
ses below e.g. 45%, adjustable, for a
preset time, a stop signal will be pro-vided
to stop the standby diesel generator.
The T2300 is intended for protection The T2400 furnishes 2 combined over-
of generators, power transmissions and current relays, intended for protection or The T2600 can serve an installation
consumer supply against damage caused monitoring of generators, power trans- with up to 3 diesel generators. With an
from short circuit by tripping the circuit missions and consumer supply. extension unit additional generators can
breaker. A typical generatorapplication is to let be served.
The relay detects the highest of the 3 one of the overcurrent functions trip the
input currents and, when the preset val- generator breaker and to let the other
ue is exceeded, an output relay will be overcurrent function trip a nonessential
activated instantly (100 msec.) or after a service. Both overcurrent functions could
preset time delay. be used to trip 2 levels of nonessential
loads. (Widely used in marine applica-
tions.)
T2700 Power Relay T3000 Frequency Relay T3200 Insulation Monitor

The T2700 is intended for detection of The T3000 is intended for effective The T3200 is intended for continuous
power level for protection, control and frequency monitoring on generators, insulation monitoring on 3 phase in-
monitoring purposes. The relay detects the busbars or other distribution systems. sulated networks on board ships. The
magnitude of the power and, when the pre- The relay contains the functions “under relay continuously monitors two systems
set value is exceeded, an output relay will be frequency” and “over frequency”, time galvanically separated from each other,
activated after a preset time delay. delayed, and 2 individual output relays, e.g. the busbar and the lighting system or
one relay for each function. two busbar systems.

T2800 Overcurrent The unit features two output relays for

or Earth Fault Relay T
 3100 and T3300 Voltage alarm purposes and two analog outputs
Relays for instrument readings.

T3500 Frequency Deviation

Relay

The T2800 has a broad application as an

earth fault or a single phase overcurrent de- The T3100 and T3300 are intended for
tection relay. It has a wide setting range for effective voltage monitoring on genera-
protection, control or monitoring. tors, busbars or other distribution systems.
The relay detects the magnitude of the The relays contain the functions “under
current and, when the preset value is voltage” and “over voltage”, time delayed, Rate of change of frequency (ROCOF)
exceeded, an output relay will be activated and 2 individual output relays, one for relay, df/dt relay. The T3500 will monitor
after a preset time delay. each function. the frequency of the connected ­busbar.
In case there is a rapid change of fre-
T3100 is for monitoring on one phase quency, the relay will trip.
T2900 3 Phase Differential
and T3300 is for 3 phase monitoring.
Current Relay

T8400 Blackout Limiter

11 12 13 14 15 16 17 18 19 20
POWER RELAY
0.16 0.28 4 7
3-PHASE
DIFF. CURRENT
RELAY T2900 0.04 0.4 1 10
xIN SEC.
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

1 2 3 4 5 6 7 8 9 10

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

The T2900 3 Phase Differential Relay is in-

tended as a protection relay for ­generators,
power transmissions and consumer’s supply The T8400 enables fast clearing of a
by tripping the main circuit breaker. blackout. If a blackout occurs, the first
The T2900 measures the differential ­current generator to have more than 90 %
of each of the 3 phases. voltage will make the generator breaker
The relay detects the highest of the 3 ­input close. It is possible to monitor up to 4
currents and, when the preset ­values are generators with 1 unit, and up to 8 gene­
exceeded, the output relay will be activated rators with 2 units.
after preset time delays.
 » About SELCO
For more than three decades, SELCO has been a market leader in providing electrical control,
monitoring and protection equipment for power generation applications worldwide.

With headquarter and manufacturing mainly in Denmark, our product portfolio is known to be of high
quality, extremely reliable and easy to use. Our partners and distributor network worldwide are vital,
in supporting our sales to more than 60 countries.

Every day, SELCO products are on a mission, in operation, around the world, to help control, protect
and enhance the safety of electrical equipment, engine and generator applications, within markets
like marine, oil & gas, power generation, and general industry.

Our scope of supply and expertise is within the following areas;

• Generator Control and Power Management Systems
• Engine Control, Protection & Monitoring
• Protection and Control Relays
• Alarm Panels and Monitoring Systems

SELCO
Betonvej 11 Tel.: + 45 - 70 26 11 22
DK- 4000 Roskilde Fax: + 45 - 70 26 25 22
Denmark e-mail: selco@selco.com selco.com