17 Samss 012

Materials System Specification
17-SAMSS-012 13 December 2011

Photovoltaic Power Supply for Cathodic Protection
Document Responsibility: Cathodic Protection Standards Committee
Saudi Aramco DeskTop Standards

Table of Contents
1 Scope............................................................. 2
2 Conflicts and Deviations…………………….... 2
3 References..................................................... 2
4 Manufacturer Requirements……………….… 3
5 General………............................................... 4
6 Design Requirements.................................... 7
7 Site Conditions............................................... 7
8 Electrical Components................................... 8
9 Mechanical Components.............................. 16
10 Labeling Requirements................................ 19
11 Inspection and Testing................................. 21
12 Spare Parts.................................................. 23
13 Export Packing and Shipping....................... 23
Appendix 1 – Battery Data Sheet........................ 25

Appendix 2 – Figures.......................................... 26
Previous Issue: 31 July 2004 Next Planned Update: 13 December 2016

Revised paragraphs are indicated in the margins Page 1 of 33
Primary contact: Catte, Darrell Raymond on 966-3-880-9630
Copyright©Saudi Aramco 2011. All rights reserved.

Document Responsibility: Cathodic Protection Standards Committee 17-SAMSS-012
Issue Date: 13 December 2011
Next Planned Update: 13 December 2016 Photovoltaic Power Supply for Cathodic Protection
1 Scope
This Specification defines the minimum requirements for a photovoltaic (PV) power
supply for cathodic protection loads.
2 Conflicts and Deviations
2.1 Any conflicts between this specification and other applicable Saudi Aramco
Materials System Specifications (SAMSSs), Engineering Standards (SAESs),
Standard Drawings (SASDs), or industry standards or codes shall be resolved in
writing by the Company or Buyer Representative through the Manager,
Consulting Services Department of Saudi Aramco, Dhahran.
2.2 Direct all requests to deviate from this specification in writing to the Company or
Buyer Representative, who shall follow internal company procedure SAEP-302
and forward such requests to the Manager, Consulting Services Department, Saudi
Aramco, Dhahran.
3 References
Material or equipment supplied to this specification shall comply with the latest edition
of the references listed below, unless otherwise noted in the purchase order.
3.1 Saudi Aramco References
Saudi Aramco Engineering Procedure

SAEP-302 Instructions for Obtaining a Waiver of a Mandatory
Saudi Aramco Engineering Requirement
Saudi Aramco Materials System Specification

17-SAMSS-511 Stationary Storage Batteries
Saudi Aramco Inspection Requirements

Form 175-173100 Inspection Requirements
3.2 Industry Codes and Standards
American Society for Testing & Materials

ASTM A36 Specification for Structural Steel
ASTM A123 Specification for Zinc (Hot Dip Galvanized)
ASTM B209 Specification for Aluminum and Aluminum Alloy
Sheet or Plate
Page 2 of 33
Institute of Electrical and Electronics Engineers, Inc.

IEEE 1262 Recommended Practice for Qualification of
Photovoltaic (PV) Modules
National Electrical Manufacturers Association

NEMA ICS 6 Enclosures for Industrial Control and Systems
NEMA 250 Enclosures for Electrical Equipment
National Fire Protection Association

NFPA 70 National Electrical Code (NEC)
4 Manufacturer Requirements
4.1 Manufacturer and Equipment Qualification Requirements
The Manufacturer shall manufacture modular Photovoltaic (PV) power supplies

for cathodic protection in accordance with the requirements detailed in this
standard. The Manufacturer shall be pre-qualified in accordance with section
4.1.1, and the Manufacturer's specific product shall be pre-qualified in
accordance with Sections 4.1.1 and 4.1.2.
4.1.1 The Manufacturer shall demonstrate to the Saudi Aramco VID or Buyer's
Inspection Representative a quality control program that clearly
describes the routine quality procedures and satisfies the inspection
requirements detailed on Form 175-173100.
For at least one modular PV power supply, the Manufacturer shall

demonstrate to the Saudi Aramco VID or Buyer's Inspection
Representative conformance to the “Design Qualification Tests” detailed
in Section 11.2 of this specification.
The Manufacturer shall provide the Saudi Aramco VID or Buyer's

Representative with full documentation as described in Sections 5.4 and
11.2 of this specification.
4.1.2 The Manufacturer shall satisfactorily demonstrate to the Saudi Aramco

Subject Matter Expert (SME), completion of the “Design Qualification
Tests,” and the “Routine Production Performance Tests” detailed in
Section 11.2 and 11.3 of this specification.
The Manufacturer shall provide the Saudi Aramco RSA with full
documentation as described in Section 5.4 and 11.2 of this specification.
Page 3 of 33
4.1.3 At least two photovoltaic power supplies with approximately equivalent

construction characteristics and output ratings must have satisfactorily
operated for at least one year in environmental conditions similar to
those detailed in Section 7.
The Manufacturer shall supply the SME with a list of users for the
above. The list shall detail; user company name and contact information,
installation location, date of installation, and general equipment
specifications.
4.2 Information Required With Quotation
Quotations shall only be supplied by Manufacturers that have been approved in

accordance with Section 4.1 of this specification, and only for equipment that
has been qualified in accordance with Section 4.1 of this specification.
The English language shall be used on all documents, drawings, labels, etc.
The Manufacturer shall supply the following information with the quotation.
The quotation will be considered technically unacceptable if any of the
information requested is not included.
Information Manufacturer Must Submit with Each Quotation:

a) Manufacturer's written certification of compliance to this specification
with clearly stated exceptions or proposed alternatives.
b) Manufacturer's written certification that the equipment and equipment
components used for the quotation meet or exceed the specifications of
those used to complete the Manufacturer's approval requirements
described in Section 4.1 of this specification. If modified or alternative
components are going to be used, then a complete set of component data
sheets shall be submitted to the Saudi Aramco SME for approval.
c) Manufacturer's certified copy of the data from the “Design Qualification
Tests” and the “Routine Performance Tests” from the unit used for the
approval procedure described in Section 4.1 of this specification.
d) Data Sheets for the Batteries, Modules, and Array Control Center (Charge
Regulator)
5 General
5.1 Abbreviations
ACC Array Control Center
AOC Aramco Overseas Company
Page 4 of 33
ASC Aramco Services Company

ASME American Society of Mechanical Engineers
ASTM American Society for Testing and Materials
AWS American Welding Society
IEC International Electrotechnical Commission
IEEE Institute of Electrical and Electronics Engineers
NEC National Electric Code
NEMA National Electrical Manufacturers Association
OCC Output Control Center
PV Photovoltaic
RSA Responsible Standard Authority
SAES Saudi Aramco Engineering Standard
SAMSS Saudi Aramco Materials System Specification
SASD Saudi Aramco Standard Drawing
SSPC Steel Structures Painting Council (USA)
STC Standard Test Conditions
5.2 Terms and Definitions (refer to Figure 1)
Array: An integrated assembly of photovoltaic modules with complete

mounting structures and wiring.
Module: A number of solar cells wired and sealed into an environmentally

protected assembly.
Modular PV Power Supply: The Modular Photovoltaic (PV) power supply is a

stand-alone, full time, solar powered DC supply for cathodic protection that can
be field connected in parallel/series arrangements with other Modular PV power
supplies. The Modular PV power supply unit consists of the following primary
components:
a) An array of photovoltaic modules
b) A bank of storage batteries
c) An array control center (consisting of charge regulator, metering & control
circuits)
d) All interconnecting hardware and supporting structures
Page 5 of 33
PV Panel: A collection of modules mechanically fastened together and wired to

form an array.
5.3 Required Documentation
5.3.1 Installation, Operating and Maintenance Instructions
One copy of the Installation, Operating and Maintenance Instructions

contained in a plastic cover, shall be included in each Array Control
Center and shall describe all of (and only) the equipment installed.
Improper and dangerous or non-recommended practices shall be
accented by bold-print.
Supporting drawings shall show only the equipment being supplied and
shall be no larger than 280 mm x 430 mm (11 in x 17 in) completely
dimensioned and labeled to include: structural details, full electrical
schematics and detailed connection diagrams including terminal block
identification and all connections to be made by the Buyer. Typical
drawings are not acceptable.
5.3.2 Component Data Sheets
Component data sheets shall be supplied as required in Section 4 of this

specification. The component data sheets shall detail the respective
Manufacturer's operating, performance, and construction specifications,
and shall include but not be limited to data sheets for the following
components:
- Zener Charge Regulation Diodes (as applicable)
- Blocking Diodes
- Solid State Charge Regulation Circuitry
- Mercury Switches
- Circuit Breakers
- Fuses
- MOV's and Surge Arrestors
- Meters
- Wires (including manufacturer's ratings and specifications for wire
insulation)
- ACC Enclosure (detailing the level of meeting the requirements of
NEMA)
- Battery Enclosure
- Batteries
Page 6 of 33
6 Design Requirements
Each Modular PV power supply shall provide a continuous output of 90 watts at a

nominal 6 Volts and 15 Amperes (360 Ampere-Hours per Day) through an Array
Control Center (ACC). The Modular PV power supplies shall be constructed such that
the output from the ACC can be connected to additional ACCs in parallel/series
combinations via an Output Control Center (OCC) to achieve a higher voltage or
current output rating to a maximum of 24 volts, 45 amperes. The cathodic protection
load shall be connected to the power supply at the OCC. The OCC shall be constructed
with a variable resistor to control load current.
Exceptions:
1. System ratings other than 6 Volts/15Amperes can be used if found to be more

economical. The system rating shall be specified to the operational requirements of the
Cathodic Protection load. Both the proponent department and CSD shall approve the
modified system based on an economical analysis that demonstrates the clear advantage
of the modified system over the regular (6 Volts/15 Amperes) system.
2. In cases where one Modular PV power supply will provide sufficient power, an OCC is not
required if the cathodic protection load is connected to the ACC through a resistor to
control load current. In such cases, the resistor shall be mounted in a separate
enclosure.
All components of the Modular PV power supply with the exception of the batteries
shall be designed for an operational life of 20 years with minimal maintenance in a
remote, unattended, desert environment as described in Section 7. The storage batteries
shall be selected for a minimum operational life of 10 years in the same environment.
7 Site Conditions
7.1 General
Location: Latitude: 17° to 32° North

Longitude: 15° to 55° East
Relative Humidity: Minimum 0%

Maximum 95% (condensing)
Ambient Temperature: Minimum 0°C (32°F)

Maximum 50°C (122°F)
Altitude: Maximum 5000 FT
Wind: Maximum 146 Km/h (88 Mph)

Gust Factor 1.46
Page 7 of 33
7.2 Onshore Environment
The normal air-borne dust concentration is 1 mg/cubic meter with 95% of all
dust particles less than 20 micrometers, and 50% less than 1.5 micrometers in
size. During sand storm conditions, dust concentration may reach 500 mg/cubic
meter and winds may gust to 146 Km/h. The dust may contain sodium, calcium,
magnesium, silicon and aluminum components. Other substances which may be
present are H2S (1 to 5 ppm), CO (50 to 100 ppm), NO(x) (1 to 5 ppm), SO2 (1 to
5 ppm), and hydrocarbons (10 to 50 ppm).
7.3 Offshore and Nearshore Environment
Equipment situated offshore, or near-shore shall be considered to be within a

severely corrosive environment, subjected to wind blown sea water spray and
the accumulation of wetted salt (NaCl) in addition to those conditions detailed in
Section 7.2.
Commentary Note:
Nearshore is defined as within one kilometer from the Arabian Gulf shoreline, and
within three kilometers from the shoreline of the Red Sea.
8 Electrical Components
Electrical components shall be rated by the manufacturer to operate in the

environmental conditions detailed in Section 7 and shall comply with NEC, Article 690.
8.1 PV Modules
8.1.1 Dimensions
Individual PV modules shall be electrically and mechanically

interchangeable between arrays of the same manufacturer and field
replacement shall be easily accomplished without specialized tools or
materials.
8.1.2 Encapsulation
The photovoltaic cells shall be mechanically and environmentally

protected. The encapsulation scheme shall provide complete moisture
and corrosion protection consistent with the environmental and life
requirements of this Specification.
8.1.3 Cell and Intercell Connections
Individual photovoltaic cells shall have multiple interconnections to

minimize reduced module output due to the failure of a cell or internal
Page 8 of 33
connections. The redundant intercell connections shall be either strain

relieved or thermally matched for thermal expansion and other
anticipated mechanical stresses.
8.1.4 Contact Integrity
Each electrical connection to the active cell area shall be soldered in at

least two locations.
8.1.5 Solder
Solder employed in cell connections shall be a nominal solder alloy of

60% tin, 40% lead and shall cover all of the contact area. The solder
flux residue shall be non-corrosive to the connection alloys.
8.1.6 Front Module Cover
Glass shall be used as the protective cover for the front of each solar
module. It shall be designed for high impact protection and thermal
shock resistance. The glass shall be tempered, water-white with very
low iron content. It shall withstand one inch hail at a velocity of
52 MPH without breakage. The glass shall have a slightly diffusing
pattern on the inner surface for enhanced light gathering capability.
The specific glass after exposure to 20,920 MJ/m² (500,000 Langleys) of
natural sunlight Air Mass 1 (AM1) shall provide a transitivity of 95% of
the initial measured value from 300 to 700 nanometers.
8.1.7 Module Frame
The module frame shall be constructed of Types 5052, 6061 or

equivalent aluminum per ASTM B209 with compatible hardware
designed to withstand the environmental conditions of Section 7.
The frame shall readily and easily accept the hardware required to attach
the module to the PV panel support structure.
8.1.8 Junction Box
Each module shall incorporate an electrical connection junction box

containing positive (+) and negative (-) module interconnection wiring
terminals mounted to the back of the module. The junction box shall be
weatherproof and shall meet the requirements of NEMA 3R.
8.2 PV Array
The array shall be wired to supply a nominal output of 6 Volts and 15 Amperes.
The array peak power shall be rated to supply a minimum of 700 watts under
Page 9 of 33
Standard Test Condition (STC), which are:

@ Illumination of 1 KW/M2 (1 sun) at spectral distribution of AM 1.5
(1.5 atmospheres).
@ Cell temperature of 25°C ± 3°C
Exception:
If a system rating other than 6 Volts/15 Amperes is specified, the design of the
PV Array shall take into consideration the new ratings and the peak power as
described above shall be proportionately increased or decreased.
The array photovoltaic modules shall be tested to meet Section 11 and provide a
minimum of 10% conversion efficiency from incident sunlight at STC.
The modules shall be warranted to maintain at least 80% of minimum rated
power for twenty years. The effect of temperature on module power shall be a
maximum of - 0.4% for each °C above the standard 25°C.
8.3 Array Control Center (ACC)
The Array Control Center shall contain the charge regulator control circuitry,
meters and circuit protection. The ACC shall also contain the terminal
connection points from the batteries, arrays and the Output Control Center, or
where applicable, the CP load. A typical electrical schematic is shown in
Appendix 2, Figure 2.
The ACC shall be built for a 6 Volt, 15 Ampere nominal operating output and
all components in the ACC shall be rated for regulating charge to the battery
bank at peak power input from the photovoltaic array.
Exception:
If a system rating other than 6 Volts/15 Amperes is specified, the design of the
Array Control Center (ACC) shall take into consideration the new ratings.
8.3.1 Charge Regulator
A charge regulator shall be provided as part of the Array Control Center

to provide efficient battery charging and to prevent overcharging of the
batteries. The charge regulator shall use electronic control circuitry to
activate and deactivate sealed mercury switches.
The charge regulator shall be constructed with two sealed mercury

switches, each rated for a minimum of 50 amps DC. The switches shall
be connected in parallel such that each switch independently services
50% of the array load.
Page 10 of 33
The two mercury switches shall be closed in the non-powered condition,

and activation and deactivation shall be independently controlled by the
electronic control circuitry to provide optimum battery charging.
Final battery charge levels shall be temperature compensated by the

control circuitry to optimize the charge level of the batteries.
Commentary Note:
Charge regulators with a temperature compensated low voltage

shutdown at 1.85 volts/cell @ 20ºC are preferred but not mandatory.
8.3.2 Array Isolation Diode
A Schottky isolation diode shall be provided in each ACC output circuit

to prevent interaction between multi-array systems. The diode shall have
a minimum peak-inverse voltage rating of 40 volts and forward
continuous current rating of 40 amperes. The forward voltage drop
across the diode at rated load shall be 0.3 to 0.7 volts.
Panel outputs shall also be isolated with diodes (minimum 40 amp

rating) to prevent interaction between panels.
All Diode connections shall be made in a secure mechanical manner

such that replacement can be made without requiring the use of
soldering.
8.3.3 Current Shunts
Shunts shall be Holloway type SW (or equivalent) with the ratings

shown in Figures 1 and 4.
8.4 Output Control Center (OCC)
8.4.1 General
The Output Control Center shall serve as a junction box for

interconnecting multiple arrays, and shall provide total system output
metering, and system load disconnect when more than one array is
required to meet the cathodic protection power requirements. A typical
schematic drawing for the OCC is shown in Appendix 2, Figure 4.
8.4.2 OCC Capacity
The OCC shall be built with a 24 Volt, 45 Amp capacity and shall
facilitate the connection of up to 12 arrays through their respective
ACCs.
Page 11 of 33
Additional output ratings over 1080 watts (24 V, 45 A System) may be

specified and stated in the Purchase Order.
Exception:
If modular PV power supply rating other than 6 Volts/15 Amperes is

specified, the design of the Output Control Center (OCC) shall take into
consideration the new ratings.
8.4.3 Single Modular PV Power Supplies
If only one array is required for the cathodic protection then an OCC can
be used or the ACC can be ordered with a pre-mounted output control
resistor enclosure, complete with resistor.
8.4.4 Multiple Modular PV Power Supplies
If more than one array is needed to provide the required power for the
cathodic protection system, an OCC shall be used to facilitate
interconnection of multiple ACCs, and connection of the integrated
power supply to the cathodic protection load. The electrical schematic
and layout details are shown in Appendix 2, Figures 4, 5 and 6.
8.4.5 Array Interconnection Terminal Board
The array interconnection terminal board (located in the OCC) shall

serve as the array series/parallel interconnecting bus in a multi-array
system. The interconnection terminals shall consist of 12 pairs (Standard
Unit) of 10 mm (3/8 in) threaded tin or electroless nickel-plated studs
(brass or copper) mounted on a fixed Bakelite panel board (see Figure 6).
Each terminal shall be designed to accept up to 25 mm² (#4 AWG) cable
with compression type terminals. All terminals shall be evenly spaced at
minimum 38 mm (1.5 in) centers vertically and horizontally in a
staggered configuration from each other to facilitate series/parallel
connection of the array by selective placement of jumpering link bars.
Equally sized link bars, tin or electroless nickel plated copper 3 mm
(1/8 in) thick, with slotted holes shall be provided to achieve
series/parallel combination of the available arrays. The array terminal
pairs shall be individually numbered (A1, A2, etc.) and appropriately
marked with “+” and “-” polarities.
8.5 ACC and OCC Meters
The Analog voltmeters and ammeters shall have a taut-band suspension

movement with 50 mV full-scale deflection. All meters shall have an accuracy
of ±2% of full-scale deflection at 25°C. The meters shall be suitable for
mounting in ferrous or non-ferrous enclosures.
Page 12 of 33
The meters shall have a 115 mm (4.5 in) X 100 mm (4 in) rectangular case to fit
into a 70 mm (2.75 in) round mounting hole. Four (4) mounting bolts located on
100 mm (4 in) X 89 mm (3.5 in) centers shall secure the meter to a panel of up
to 6 mm (¼ in) thickness.
Analog meter scales material shall be aluminum and shall be marked and labeled
in even increments of volts or amps. Each scale shall be clearly marked as 'DC
Volts' or 'DC Amperes'. The meter full-scale values shall be as illustrated in
Appendix 2, Figures 2 and 4.
8.6 ACC and OCC Circuit Breakers
Disconnect and short circuit protection shall be provided by molded case circuit
breakers suitable for the applicable environment. The breakers shall provide
inverse time delay overload and instantaneous short circuit protection.
The breaker shall be standard NEMA frame, and ambient compensated for
operation from 0°C to 50°C with the tripping characteristic remaining the same
throughout this temperature range. The interrupting rating shall be minimum
5,000 amperes RMS symmetrical. The breakers shall be sized to carry 120% of
the rated circuit current. The temperature rating and the ampere rating shall be
visible and clearly marked in accordance with the NEC requirements.
The different circuit breakers (at ACC & OCC) shall be of the same physical
size and shall have the same mounting dimensions
8.7 ACC and OCC Field Connection Terminal Boards
8.7.1 ACC Field Connection Terminal Board
Field wiring terminal blocks at the Array Control Center (ACC) shall
have screw type terminals with full depth insulating barriers except when
the ACC is ordered for a single array CP system and the output control
resistor enclosure is mounted on the ACC. In this case, the ACC shall
use field terminals conforming to 9.3.2.
8.7.2 OCC Field Connection Terminal Board
Field wiring terminal at the Output Control Center (OCC) shall be 3/8"
post type, tinned or electroless nickel plated, brass or copper, for full-
ring type terminal lugs; and shall be fitted with double locking nuts and
washers. Terminal posts shall have adequate clearance from other
components and shall be located at least 150 mm (6 in) above the cable
entries. Manufacturer shall ensure that there is adequate room inside the
enclosure for proper termination of the rigid field cables.
Page 13 of 33
8.8 ACC and OCC Instrument Panels
All instruments (ammeters, voltmeters, etc.) shall be mounted on an internal

hinged panel with approximately 90° swing capability to provide complete
access to the back of instruments. The panel shall be held in the closed position
with two (2) captive wing or knurled fasteners. Wiring from the back of the
panel shall be neatly bundled and secured with plastic ties. No incoming field
wiring shall terminate on the swing-out instrument panel.
8.9 Wires and Cables
8.9.1 General
All wires shall be flexible stranded copper conductor with 600 volts
insulation, and shall be compatible with the specified environment.
Wires shall not be tapped or spliced between terminal points. Wiring
shall be neatly bundled and secured with loose fit plastic ties.
All interconnection wiring between the primary components of the PV

power supply shall be installed in flexible metallic conduits.
Conductors shall be sized for the appropriate amperage in accordance

with NEC. Minimum wire sizes shall be as follows:
a) ACC power circuit (Internal): 10 mm² (#8 AWG)
b) OCC power circuit (Internal): 16 mm² (#6 AWG)
c) ACC & OCC meters and control (Internal): 0.75 mm² (#18 AWG)
d) ACC to Battery: 35 mm² (#2 AWG)
e) Solar Panels to ACC: 25 mm² (#4 AWG)
f) ACC's to OCC: 16 mm² (#6 AWG)
8.9.2 Wire and Cable Terminals
All wire and cable terminations (10 AWG or smaller) shall be with pre-
insulated ring type terminals and shall be installed with a crimping tool
that crimps both the terminal and the conductor. All wire and cable
terminations larger than 10 AWG shall be crimped, soldered and
insulated ring terminals.
No more than two wires shall be terminated on one terminal screw.

Terminal blocks shall have tinned or electroless nickel plated screw type
terminals, and shall be rated for 300 volts (minimum) with full depth
insulating barriers.
Page 14 of 33
8.9.3 Wire and Cable Identification and Labeling
Each conductor shall be identified by a permanent wire marker within

25 mm (1 in) of each termination, and shall have a number and color
identification corresponding with the operating manual schematic
diagram. Adhesive type labels are not acceptable.
8.10 Output Control Resistors
Resistors of 0.17 and 0.56 ohm value shall be provided in an output control
resistor enclosure fastened to each Output Control Center, or when detailed on
the purchase order, the output control enclosure and resistors shall be mounted
on the Array Control Center for single array CP systems.
 Each resistor shall have a continuous power rating of 400 watts.
 Resistors shall be edge-wound power type, wound on ceramic insulators
with stainless steel support and mounting hardware.
 Each resistor shall have a minimum of seven (7) continuously welded fixed
position taps including the end terminals. Spot welded taps shall not be
acceptable.
 Tap terminals shall have bolted connections with brass or phosphor bronze
hardware.
 Resistors shall be stamped or engraved with the resistance and watt value for
identification.
8.11 Storage Batteries
8.11.1 Batteries shall be designed for photovoltaic application and suitable for
use in the environmental conditions of Section 7. The batteries shall be
lead acid vented type, tubular plate design, unless specified otherwise
in the purchase order. The proposed battery must be approved by the
Saudi Aramco SME representative, or his delegate.
8.11.2 Batteries shall meet the design, performance and test requirements of
17-SAMSS-511, Section 7, 8 or 9 as applicable for photovoltaic
application.
8.11.3 The batteries shall have a minimum rated storage capacity of

1350 ampere-hours at a 120-hour discharge rate. The battery bank shall
be sized for a final voltage (end of capacity) of 1.85 volts/cell at 20°C.
8.11.4 The batteries shall perform in an application requiring a daily discharge

of up to 20% of it's rated ampere-hour capacity, and deep discharges to a
depth of 80% of rated capacity at the 120 hour discharge rate.
Page 15 of 33
8.11.5 The batteries shall be suitable for operation at 25-50% state of charge
for extended periods of up to 60 days.
8.11.6 The battery cells shall be designed to accept high charging current at
system voltages as low as 6.3 volts to allow fast recharge at the
nominal 6 hour rate.
8.11.7 Ampere-Hour charging efficiency shall not be less than 90%.
8.11.8 Self-discharge rate shall not exceed 3% per month at 25°C.
8.11.9 Rated cycle life (number of charge-discharge cycles under the

environmental conditions of Section 7) shall be a minimum of
4,000 cycles at a daily average depth of discharge of 20% of rated
capacity. The rated cycling performance is at 20°C.
8.11.10 Lifting handles, either built-in or externally attachable, shall be

provided to facilitate two-man removal of the individual cells from the
battery box.
8.11.11 The battery bank shall have no more than 2 parallel strings.
8.11.12 Cell-to-cell connections shall be in accordance with 17-SAMSS-511

requirements.
9 Mechanical Components
9.1 PV Array Support Structure
9.1.1 The PV array support structure shall have a fixed tilt angle of 45° for the
photovoltaic modules. It shall be designed for mounting on concrete
footings with anchor bolts.
9.1.2 Material shall be ASTM A36 hot-dipped galvanized steel conforming to

ASTM A123. All welding shall be continuous seal welds with no
crevices. Cutting, drilling, etc., shall be performed prior to galvanizing.
All hardware that cannot be galvanized shall be Type 316 stainless steel.
9.1.3 Allowance for thermal expansion differentials shall be provided between

aluminum solar modules and steel support structure. Self-locking
hardware and nylon washers shall be used where specific torque is
needed to allow for thermal expansion.
Page 16 of 33
9.1.4 Mounting
9.1.4.1 General
The structure shall have mounting provisions for the Array

Control Center (ACC), Output Control Center (OCC), and all
associated wiring cable trays and conduits. The design shall
include space and comfortable access allowance for the control
centers and the storage battery enclosure.
9.1.4.2 Mounting Heights & Cleaning Provisions
Mounting height of the lower edge of photovoltaic modules

shall not be less than 762 mm (30 inches) above grade. Upper
edge of the photovoltaic modules shall not exceed 2920 mm
(9.5 feet) above grade, at a tilt angle of 45 degrees, to keep
modules within reach for cleaning. Adequate clearances shall
also be provided on each side of the individual PV panels for
cleaning access.
9.2 Storage Battery Enclosure
The battery enclosure shall be designed for above grade installation under the
shade of the PV panel. Material shall be 6 mm (¼ in) thick fiberglass reinforced
plastic.
The design shall include a removable lid secured by at least four (4) Type
304/316 stainless steel quick- release (no tools needed) latches with stainless
steel hardware. The lid shall support a minimum of 80 kg (176 lbs) in the center
and shall be fabricated to allow removal by a single person.
The enclosure shall be completely weatherproof, dust-tight, and rain tight.

The gasket shall be one piece black neoprene or buna nitrile rubber with a (one)
sealed joint. It should be either mechanically attached to the enclosure lip and in
continuous contact with the latched lid or fully framed and fastened to the lid
with an epoxy adhesive. Two vent plugs shall be provided to release hydrogen
gas without allowing sand/ dust to enter the enclosure. Vent pipes are not
acceptable. The enclosure base shall be ribbed for structural strength with two
drain holes (approximately 6 mm) in each depression. Two external anchoring
tabs shall be provided on each end of the enclosure for mounting on concrete
footings. A 1½ inch female threaded conduit hub shall be provided on the end
towards the solar ACC for incoming battery cables.
The following safety and maintenance instructions engraved on plastic, etched

on stainless steel, or made permanent in any other similar manner shall be
Page 17 of 33
secured to the top exterior of the enclosure lid. These instructions shall also
carry any special notices by the battery manufacturer including the following:
Maintenance Instructions
1. Voltage at 100% state of charge = _______ volts/cell
2. Fully discharged voltage = _______ volts/cell
3. Ampere hour capacity = _______ A-H/cell
Safety Instructions
1. Isolate input circuit breakers before disconnecting the batteries.
2. Always wear protective clothing and eye protection.
3. No smoking or sparks - danger of hydrogen gas.
4. Check connections for tightness.
5. Close and latch cover tightly to avoid entry of sand and dust.
9.3 Array Control Center & Output Control Center Enclosures
9.3.1 General
These enclosures shall be completely dust and water tight and shall be
built and rated to NEMA 4X (NEMA 250) specifications. Material
thickness shall meet the requirements of NEMA ICS 6.
The enclosure door shall have a minimum of two quick-release latches.

Metallic hinges, latches and all other metal hardware shall be Type
304/316 stainless steel.
Enclosure shall be sized to provide a minimum of 150 mm (6 in) of

working and cable bending space below the field wiring terminals.
9.3.2 Array Control Center (ACC) Mounting
The Array Control Center enclosure shall be secured above ground to the
PV panel support structure and shall be completely shaded at all times by
the photovoltaic modules. The enclosure shall be securely bolted in
place and positioned for easy access by maintenance and operations
personnel at a convenient height for monitoring and maintenance.
The layout of the PV panel structure and the location of the battery
enclosure shall provide unobstructed access to the Array Control Center
enclosure. Control center mounting height, centerline to ground, shall be
greater than 1.25 m and less than 2 m.
Page 18 of 33
9.3.3 Output Control Center (OCC) Mounting
The Output Control Center enclosure shall be secured in a manner

similar to the Array Control Center (Section 9.3.2) and fully shaded by
the PV panel. The layout of the PV panel structure and the location of
the battery enclosure, etc., shall provide unobstructed access to the
Output Control Center enclosure. Mounting height shall be the same as
for the Array Control Center.
9.4 Output Control Resistor Enclosure
9.4.1 General
These enclosures shall be constructed with ventilated openings designed

to minimize entrance of wind blown dust and rain, and shall be built to
meet the requirements of NEMA 3R specifications.
Enclosure material shall be aluminum alloy type 5052 or equivalent.

Minimum thickness shall be based on the size of the enclosure per
NEMA ICS 6. Enclosure shall be sized to provide at least 100 mm (4 in)
of working and wire bending space all around the periphery of the
resistor.
9.4.2 Output Control Resistor Enclosure Mounting
The resistor enclosure shall be externally attached to the OCC enclosure,

or in the case of a single array CP system without an OCC, the resistor
enclosure shall be externally attached to the ACC.
9.5 Fittings and Conduit Hubs
Unless otherwise noted all required cable fittings and conduit hubs shall be
provided and installed by the Manufacturer. Sizes shall be compatible with the
minimum wire sizes specified in Section 8.9. The terminals and cable fittings for
the two output load cables shall be suitable for 185/240 mm² (350/500 MCM)
cables unless otherwise noted on the purchase order. See typical layouts of ACC
(Figure 2) and OCC (Figure 5) for the locations and quantities required.
10 Labeling Requirements
10.1 Each component shall be identified by function and rating where appropriate.
Terminals shall be marked “+” or “-” to designate polarity. Panel marking shall
be white, yellow, or red letters on engraved labels (adhesive type labels are not
acceptable). Red warning labels shall be placed where appropriate to caution
operators of dangerous or unsafe practices or conditions. A wiring schematic
Page 19 of 33
depicting the factory wiring for all electrical components shall be mounted on
the inside of the ACC and OCC enclosure doors.
10.2 A warning label engraved on plastic or etched on stainless steel shall be made
permanent on the exterior of the Battery, ACC and OCC enclosure doors stating:
WARNING: To avoid damage to regulator circuits, switch off all input circuit
breakers before disconnecting the batteries or load.
10.3 The following information shall be permanently marked on each cell:

a) Manufacture's name
b) Manufacture's catalog number or type reference
c) Voltage
d) Capacity rating
e) Electrolyte density (fully charged at 25°C)
f) Date of manufacture
10.4 Nameplates
An equipment identification nameplate shall be attached to the outside of the

following components by Type 304 or 316 stainless steel screws or rivets.
a) Array Control Centers
b) Output Control Centers
c) Battery Enclosures
Nameplates shall be stainless steel, minimum 22 gauge thickness and stamped or

engraved with the following information:
d) “Photovoltaic Power Supply - Cathodic Protection”
e) “Specification: 17-SAMSS-012, dated (as applicable)”
f) Component: “Photovoltaic Power Supply,” “Array Control Center,”
“Output Control Center” or “Battery Enclosure” (as appropriate)
g) Manufacturer
h) Model Number
i) Serial Number
j) Date Manufactured
k) Purchase Order Number
l) Output Rating - where applicable.
Page 20 of 33
11 Inspection and Testing
11.1 Inspection
Inspection shall be carried out in accordance with Form 175-173100 attached to

the Purchase Order. Failure of any component to meet the requirements of this
Specification shall be justification for the Buyer's Inspector to request further
tests on similar components of that Purchase Order.
11.2 Design Qualification Tests
The following Design Qualification Tests and procedures shall be performed on

one system on a one time per design basis and shall be witnessed and approved
by the Buyer's Inspector. These tests shall be conducted at the Manufacturer's
facility at 20°C to 25°C using a regulated DC power supply (to simulate the
solar array input) with no more than one 1% ripple and set to operate at the
maximum current and voltage of the solar array at STC.
11.2.1 Assembly
The Manufacturer prior to Buyer's acceptance shall assemble a

complete Modular Photovoltaic power system. The purpose of this is
to demonstrate mechanical fit and size compliance of all components.
11.2.2 Array Control Center (ACC)
11.2.2.1 Operation at Rated Load and Maximum Ambient

Temperature
The ACC shall be performance tested at rated load at

55°C (122°F) for 24 hours. Test certificates shall indicate
successful performance of all solid-state components,
circuit protective devices, and construction materials.
The temperature shall be chart recorded during tests and
available to the Buyer's Inspector. An enclosure surface
temperature higher than 65°C shall not be acceptable.
The surface temperature of heat sinks, diodes, and resistors
higher than 110°C shall not be acceptable.
11.2.2.2 Short Circuit
This test shall be conducted on the ACC after it has been

preconditioned by 11.2.2.1.
Starting at room temperature the system output terminals

shall be fully short circuited with all protective devices
Page 21 of 33
properly in place. Confirm proper operation of all

protective devices and no damage to system components
and wiring. Repeat the test five (5) times with an interval
of 5 minutes (or more) between repetitions.
11.2.2.3 Open Circuit
This test shall be conducted on the ACC after it has been

preconditioned by 11.2.2.1. The duration of test shall be
48 hours under continuous maximum DC input power.
With the system batteries in fully charged condition

disconnect the system load. At the end of test, check and
record the case temperature of all solid-state devices.
An enclosure surface temperature higher than 60°C shall be
deemed unacceptable. Surface temperature of heat sinks,
diodes, and resistors higher than 110°C shall be deemed
unacceptable.
11.2.3 Module Environmental Tests
Modules shall be subjected to the following tests per IEEE 1262:

a) Thermal cycle test.
b) Humidity cycle test.
c) Mechanical loading test.
d) Twist test.
e) Hail-impact test.
f) Wet insulation Resistant.
g) Damp heat test.
h) Ultraviolet conditioning test.
i) Electrical-Isolation Test (dry and wet hipot).
11.2.4 Module Electrical Performance Test
Current - Voltage characteristics (I-V curve) measurements shall be

obtained for each Module at STC per IEEE 1262. Each Module power
peak shall be equal to or greater than the Module rated peak output
power under STC.
11.2.5 Battery Tests
Batteries shall be tested in accordance with IEC 60896-1 or

IEC 60896-2 as applicable.
Page 22 of 33
All power for this test shall be supplied by the system's fully charged
battery bank. The load current shall be adjusted to 15 amperes from
the batteries with the simulated DC input power or photovoltaic array
disconnected. The test shall continue for 96 hours or until the battery
terminal voltage drops to below 1.85 volts per cell. Performance less
than 96 hours shall be deemed unacceptable.
11.3 Routine Production Performance Tests
One Modular Photovoltaic Power Supply shall be assembled for each Purchase
Order to confirm fit inclusion of all required hardware. In addition, the Array
Control Center (ACC) tests detailed in Section 11.2.2 shall be conducted on a
minimum of one ACC per purchase order.
Witnessing of the Routine Production Performance Tests by the Buyer's

Inspector is not required, however, the Manufacturer shall provide certification
with each purchase order that clearly states the Routine Production Performance
Tests have been successfully completed for that purchase order.
12 Spare Parts
The Manufacturer shall submit within 30 days of confirmation of the order a list of
priced spare parts recommended to be on hand during system start-up and the first year
of operation.
In addition, the following spare parts shall be provided with each Modular Photovoltaic
Power Supply:
a) 2 each spare fuses of each type (if applicable).
b) 5% spares for all nuts, bolts, washers and other fittings required for assembly in
Saudi Arabia.
All spare parts shall be properly labeled, secured, and shipped inside the appropriate
enclosures.
13 Export Packing and Shipping
The method of packing and shipping of the solar module, Array Control Centers,
Output Control Centers and batteries shall be such as to protect all components against
corrosion, dampness, breakage or vibration during transportation and handling by sea or
air to Saudi Arabia. Long term storage in outdoor sunlight and blowing sand/dust shall
be expected. Packing shall comply with Saudi Aramco Packing Specifications for
Export Shipment. All openings in enclosures or connection boxes and equipment shall
be effectively sealed with gasket steel plates or threaded steel or schedule 40 plastic
plugs as appropriate.
Page 23 of 33
Batteries shall be shipped in charged and dry condition. Individual batteries shall be
wrapped and sealed against moisture. Individual cell boxes shall be printed with
handling and storage instructions, including a warning against lifting the cells by
terminal posts.
Revision Summary
13 December 2011 Revised the "Next Planned Update." Reaffirmed the contents of the document, and
reissued with minor changes to be in line with the new CSD RVL process and new industry
standards.
Page 24 of 33
Appendix 1 - Battery Data Sheet
1 Buyer's Quotation Request/Purchase Order No. ________________

2 Buyer's Line Item No .______________________
3 Battery Type: ______________________
4 Nominal Battery Voltage: ______________________ volts
5 Number of Cells: _____________ ; Plate Composition: ___________
6 No. of Positive Plate/Cell: __________________
7 Max. Battery Float Voltage: ________ volts
8 Equalize Voltage: ______________ volts/cell
9 Max. Float Voltage: ______________ volts/cell
10 Maintenance Interval: ______________ Months;
11 Cycle capability at CI rate: ___________
12 Nominal Ampere-Hour Capacity: ________ at ______ hour rate
13 Self Discharge Rate/Month: ________ at 25°C. ______ at 40°C
14 Efficiency Factor: _____________ CN/month at 25°C.
15 The Capacity Rating of a single Cell at 25°C.
Time Amperes Time Amperes Time Amperes
1 Hour ________ 8 Hours ________ 24 Hours ________
96 Hours ________ 120 Hours ________ 500 Hours ________
16 Weight/Cell: ________ Kg _______ lb.

17 Cell Dimensions: L:__________;W:___________;H:__________
18 Expected Service Life:_____ Years At 25°C; _____ Years At 40°C
_______________________________________________________________
Approved By:___________________ Dwg. No. ___________________
Date: _________________________ Revision No. ___________________
Page 25 of 33
Appendix 2
Figure 1 – Identification of Solar Photovoltaic System Components
Page 26 of 33
Appendix 2 – Continued
-100
A 100 0
A 50 0
V 15
BATTERY CURRENT
(+) (-) (+) 5
LOAD CURRENT
(-)
MODULE VOLTAGE
(+) (-)
61mm
24'’ (TYP.)
CP Load Current Shunt

Electronic
Control
Circuit
Heat Sink Battery Charge Current Shunt
Shottky Diodes
(5 Places)
24'’ (TYP.)
61mm
WARNING
ALWAYS SWITCH
OFF ALL PV
PANELS BEFORE
DISCONNECTING
BATTERIES
LOAD
1 2 3 4 CIRCUIT
PV PANEL BREAKER
CIRCUIT BREAKERS (30A)
(50 A)
TYP.
1 2 3 4 1 2 3 4 + - + -
150mm
PV PANEL (+) PV PANEL (-) BATTERY OUTPUT

(6'’)
Figure 2 – Array Control Center Layout
Page 27 of 33
Appendix 2 - continued
Figure 3 – Multi-Array Block Diagram
Page 28 of 33
Appendix 2 – continued
Figure 4 – Output Control Center Schematic
Page 29 of 33
Figure 5 – Output Control Center Typical Layout
Page 30 of 33
Figure 6 – Array Configuration Terminal Board Layout
Page 31 of 33
Subject Index
Section Subject
1 Scope
2 References
3 Conflicts and Deviations
4 Manufacturer and Vendor Requirements
4.1 Manufacturer and Equipment Qualification Requirements
4.2 Information Required With Quotation
5 Documentation
5.1 Abbreviations
5.2 Terms and Definitions
5.3 Installation, Operating and Maintenance Instructions
5.4 Component Data Sheets
6 General Design Requirements
7 Site Conditions
7.1 General
7.2 Onshore Environment
7.3 Offshore and Nearshore Environment
8 Electrical Components
8.1 PV Modules
8.1.1 Dimensions
8.1.2 Encapsulation
8.1.3 Cell and Intercell Connections
8.1.4 Contact Integrity
8.1.5 Solder
8.1.6 Front Module Cover
8.1.7 Module Frame
8.1.8 Junction Box
8.2 PV Array
8.3 Array Control Center
8.3.1 Charge Regulator
8.3.2 Array Isolation Diode
8.3.3 Current Shunts
8.4 Output Control Center
8.4.1 General
8.4.2 OCC Capacity
8.4.3 Single Modular PV Power Supplies
8.4.4 Multiple Modular PV Power Supplies
Page 32 of 33
Section Subject
8.4.5 Array Interconnection Terminal Board
8.5 ACC and OCC Meters
8.6 ACC and OCC Circuit Breakers
8.7 ACC and OCC Terminal Boards
8.7.1 ACC Field Connection Terminal Board
8.7.2 OCC Field Connection Terminal Board
8.8 ACC and OCC Instrument Panels
8.9 Wires and Cables
8.9.1 General
8.9.2 Wire and Cable Terminals
8.9.3 Wire and Cable Identification and Labeling
8.10 Output Control Resistors
8.11 Storage Batteries
9 Mechanical Components
9.1 PV Array Support Structure
9.2 Storage Battery Enclosure
9.3 ACC and OCC Enclosures
9.3.1 General
9.3.2 Array Control Center (ACC) Mounting
9.3.3 Output Control Center (OCC) Mounting
9.4 Output Control Resistor Enclosure
9.4.1 General
9.4.2 Output Control Resistor Enclosure Mounting
9.5 Fittings & Conduit Hubs
10 Labeling Requirements
11 Inspection and Testing
11.1 Inspection
11.2 Design Qualification Tests
11.2.1 Assembly
11.2.2 Array Control Center (ACC)
11.2.3 Module Environmental Tests
11.2.4 Module Electrical Performance Test
11.2.5 Battery Tests
11.3 Routine Production Performance Tests
12 Spare Parts
13 Export Packing and Shipping
Page 33 of 33

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Materials System Specification

17-SAMSS-012 13 December 2011

Saudi Aramco DeskTop Standards

Appendix 1 – Battery Data Sheet........................ 25

Previous Issue: 31 July 2004 Next Planned Update: 13 December 2016

Copyright©Saudi Aramco 2011. All rights reserved.

2 Conflicts and Deviations

3.1 Saudi Aramco References

Saudi Aramco Engineering Procedure

Saudi Aramco Materials System Specification

Saudi Aramco Inspection Requirements

3.2 Industry Codes and Standards

American Society for Testing & Materials

Institute of Electrical and Electronics Engineers, Inc.

National Electrical Manufacturers Association

National Fire Protection Association

4.1 Manufacturer and Equipment Qualification Requirements

The Manufacturer shall manufacture modular Photovoltaic (PV) power supplies

For at least one modular PV power supply, the Manufacturer shall

The Manufacturer shall provide the Saudi Aramco VID or Buyer's

4.1.2 The Manufacturer shall satisfactorily demonstrate to the Saudi Aramco

4.1.3 At least two photovoltaic power supplies with approximately equivalent

4.2 Information Required With Quotation

Quotations shall only be supplied by Manufacturers that have been approved in

Information Manufacturer Must Submit with Each Quotation:

ASC Aramco Services Company

5.2 Terms and Definitions (refer to Figure 1)

Array: An integrated assembly of photovoltaic modules with complete

Module: A number of solar cells wired and sealed into an environmentally

Modular PV Power Supply: The Modular Photovoltaic (PV) power supply is a

PV Panel: A collection of modules mechanically fastened together and wired to

5.3 Required Documentation

5.3.1 Installation, Operating and Maintenance Instructions

One copy of the Installation, Operating and Maintenance Instructions

5.3.2 Component Data Sheets

Component data sheets shall be supplied as required in Section 4 of this

Each Modular PV power supply shall provide a continuous output of 90 watts at a

1. System ratings other than 6 Volts/15Amperes can be used if found to be more

Location: Latitude: 17° to 32° North

Relative Humidity: Minimum 0%

Ambient Temperature: Minimum 0°C (32°F)

Altitude: Maximum 5000 FT

Wind: Maximum 146 Km/h (88 Mph)

7.2 Onshore Environment

7.3 Offshore and Nearshore Environment

Equipment situated offshore, or near-shore shall be considered to be within a

Electrical components shall be rated by the manufacturer to operate in the

Individual PV modules shall be electrically and mechanically

The photovoltaic cells shall be mechanically and environmentally

8.1.3 Cell and Intercell Connections

Individual photovoltaic cells shall have multiple interconnections to

connections. The redundant intercell connections shall be either strain

8.1.4 Contact Integrity

Each electrical connection to the active cell area shall be soldered in at

Solder employed in cell connections shall be a nominal solder alloy of

8.1.6 Front Module Cover

8.1.7 Module Frame