SPEC. NO.
754 : 10-2016
PAGE 1
SPECIFICATION NO. 754
192 kV SURGE ARRESTER AND SURGE COUNTER
FOR ALTERNATING CURRENT SYSTEM
(FOR 230 kV SYSTEM)
754A Scope
754A1 This specification describes the requirement with which the manufacturer shall
comply in order to supply 192 kV surge arrester and surge counter for alternating
current system (for 230 kV system) to the Metropolitan Electricity Authority
(MEA), Thailand.
754B Site and Service Condition
The surge arresters and surge counter shall be installed in the Bangkok Metropolis,
Thailand. The service conditions are as follows : -
a) Altitude : approximately mean sea level.
b) Maximum temperature : 40 ºC.
c) Average temperature in any one year : 30 ºC.
d) Average relative humidity in any one year : 79%.
e) Average maximum relative humidity in any one year : 94%.
f) Isokeraunic level : 100 days/year.
The surge arrester and surge counter shall be suitable for use in tropical climatic area
and shall be capable of operating successfully in the service conditions mentioned
above.
754C Reference Standards
Except otherwise specified elsewhere in the specification, the surge arrester and surge
counter shall be manufactured and tested in conformity with the standards listed
below.
Thai Industrial Standard Institute (TISI):-
No. 2366-2551 : Surge arresters-Part 4: Metal-oxide surge arresters without
gaps for a.c. systems.
International Electrotechnical Commission (IEC) Publication:-
IEC 60099-4 (2006) : Surge arresters-Part 4: Metal-oxide surge arresters without
gaps for ac systems.
SPEC. NO.754 : 10-2016
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Note
1. The surge arrester tested in accordance with the later version of the above
standard is also accepted.
2. The surge arrester tested in accordance with older version or draft version of
the above standard are also accepted provided that the test report is
conformed to standard and year mentioned above.
3. For TIS standard no. 2366-2551 shall be applied for Thai manufacturer.
If there are any minor parts deviated from the standards, they shall be clearly
mentioned in the "DEVIATION FROM MEA'S SPECIFICATION FORM" attached herewith.
The equipment complies with other national standards having similar characteristics and
providing equal performance and/or quality to those specified may be proposed. In this
case, the complete ENGLISH language copies of the standards shall be submitted with
the quotation; otherwise such offer may not be considered.
754D Test, Inspection and Test Report
754D1 The proposed surge arrester shall have successfully passed all the type tests or
design tests in accordance with the reference standards. The test report
according to clause 754G6 is also required and shall be submitted.
Except otherwise specified elsewhere in the specification, all test reports shall
be attached to the bid, otherwise such offer shall not be considered.
754D2 Standard factory tests shall be made, each surge arrester shall be tested
consisting of at least the following items: -
Unit required for
Test Items Unit Tested
inspection (if any)
Residual voltage test at Nearest lower whole
nominal discharge current number to the cube
root of the purchase
quantity Nearest lower whole
Measurement of reference number to the cube
voltage at reference current root of the purchase
quantity
Leakage check (for arrester All Units
units with sealed housing)
Partial discharge test
754D3 MEA reserves the right to send the representative at his expense to inspect the
material and to witness the tests at the manufacturer's works. The
manufacturer shall afford the MEA's representative all reasonable facilities to
SPEC. NO.754 : 10-2016
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satisfy him that the materials, equipment and all tests are in accordance with
the specification.
754D4 Prior to the shipment, the supplier shall submit to MEA the complete and
certified reports of all tests made in 6 (six) copies. The test reports shall
contain all data required for their complete understanding such as; diagrams,
methods, instruments, constants and values used in the tests and the results
obtained. If MEA has his own inspector, the supplier shall submit all the above
test reports to the inspector and the inspector himself shall certify the
witnessed test report and review the remainder before submitting to MEA.
754E Drawings and Instructions
754E1 Supplier shall furnish 10 (ten) copies each of the following items within 120
(one hundred and twenty) day after the effective date of contract for the
design approval by MEA otherwise the late penalty shall be applied (see
section 5).
a) Dimensional drawing of surge arrester, surge counter, mounting bracket,
terminal connector and other necessary accessories for complete
installation.
b) Installation and operating instructions.
c) Complete part lists.
754E2 One complete set of drawings and instructions listed in clause 754E1 shall be
firmly attached to or boxed with each set of the surge arrester at the time of
shipment.
754E3 All drawings except standard shop drawings, characteristic curves and
installation instructions shall have the contract marked thereon.
754E4 All drawings and instructions shall be in ENGLISH. Information on drawing shall
be engineering lettering. Instruction manual shall be machine printed or typed.
754E5 All measurements and quantities shall be expressed in the unit of METRIC
SYSTEM. If they are expressed in other system, the metric equivalent shall also
be shown.
754F System Data
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Nominal system voltage (kV) 230
Rated maximum system voltage (kV) 245
Rated frequency (Hz) 50
Temporary overvoltage
Duration (sec) 1
Earth - fault factor 1.4
Amplitude (kV) -g 198
Installation -g
Insulation level of protected
equipment (BIL) (kV peak) 1050
Short circuit current (kA) 50
754G General Requirement
754G1 The voltage ratings of the required surge arrester are listed in clause 754H.
754G2 Bidder shall provide graphical analysis comparing worse case system conditions
versus the overvoltage withstand capability of the surge arrester.
754G3 The surge arrester shall withstand continuous operating voltage of the system
listed in clause 754F: Rated maximum system voltage.
754G4 The creepage distance of surge arrester housing shall be not less than
25 mm/kV of the rated nominal system voltage. E.g. 6,125 mm for 192 kV
arrester (230 kV system voltage).
754G5 The nameplate of arrester shall be identified by the following minimum
information which shall appear on a nameplate permanently attached to surge
arrester:-
- the purchase contract number
- continuous operating voltage
- rated voltage
- rated frequency, if other than one of the standard frequencies
- nominal discharge current
- rated short circuit current in kA r.m.s
- the manufacturers name or trademark, type and identification of the
complete arrester
SPEC. NO.754 : 10-2016
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- the year of the manufacture.
754G6 Surge arrester shall also pass additional test as follows:-
a) Moisture ingress test.
b) Weathering ageing test according to IEC 60099-4 or tracking and erosion test
according to IEC 61109 or equivalent test. The duration of test shall be
5,000 hours.
c) Short circuit test according to IEC 60099-4 to verify non fragment of surge
arrester housing during internal arc fault. The tested current of short circuit
test shall be at least 50 kA (rms symmetrical) 0.2 second.
754H Ratings and Features
The surge arrester shall have the following rating.
Rated frequency Hz 50
Nominal discharge current kA 20
Rated voltage (Ur) kV 192
Maximum residual voltage at nominal
8/20 s discharge current kV peak 480
Minimum current impulse withstand
High current impulse
-Peak value of high current impulse kA peak 100
-Wave shape of current impulse s 4/10
Long duration current impulse
-Peak current A peak see note 2
-Virtual duration of peak s see note 2
Line discharge class (according to IEC 60099-4) Class 4
Note 1. TOV capability of the proposed surge arrester shall be investigated for proper
application with graphical analysis and be subjected to MEA's consideration.
2. The peak current and duration of peak shall be as specified in long duration current
impulse withstand test of IEC 60099-4 according to line discharge class.
754I Special Requirement
754I1 The surge arrester shall be single column gapless metal-oxide type and having
polymeric housing only.
754I2 A surge arrester shall be supplied with suitable insulating base mounted.
In case to connect with surge counter, the terminal for connected shall be
provided.
754I3 Each unit shall be supplied with clamp type line terminal connector suitable
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for 400 mm2 Aluminum conductor and ground terminal connector suitable for
240 mm2 copper conductor.
754J Surge Counter
754J1 Surge counter shall be weatherproof sealed type suitable for outdoor
installation.
754J2 No auxiliary supply or battery required for the operation counter.
754J3 The surge counter shall be suitable for installation in individual earth
connection installation, and shall be furnished with accessories, if any, for
complete function.
754J4 The maximum voltage drop across the counter will not exceed 2.5 kV during
the passage of high surge current to earth. The discharge of this capacitor,
through an electromechanical counter, indicates on a cyclometer type register
the operation of a connected surge arrester.
754K Additional Requirements for Packing
754K1 The surge arrester and materials to be supplied for each surge arrester shall be
individually packed with installation instruction and the list of materials. The
package shall be strong enough to withstand external force during
transportation, storage and handling. The surge arrester packed in plastic bag is
not accepted.
754K2 If any parts are packed in the cartons for containerized shipment, the cartons
shall be arranged into pallets so as to facilitate their movement by forklift
trucks.
754L Additional Requirement for Responsibility
If any surge arrester is damaged within the guaranteed period, the manufacturer shall
promptly investigate, repair or replace it. The replacement shall reach MEA within 60
days after being first informed otherwise the performance security shall be forfeited.
