15-TMSS-02-R0

TRANSMISSION MATERIALS STANDARD SPECIFICATION

15-TMSS-02, Rev. 0

TABLE OF CONTENTS 1.0

SCOPE

2.0

CROSS REFERENCES

3.0

APPLICABLE CODES AND STANDARDS

4.0

DESIGN AND CONSTRUCTION REQUIREMENTS 4.1 4.2 4.3 4.4 4.5 4.6 4.7

General Design Criteria Ratings Materials Fabrication Dimensions Markings

5.0

TESTS

6.0

DATA SCHEDULE

15TMSS02R0/MAA

Date of Approval: April 9, 2006

PAGE NO. 2 OF 15


1.0

15-TMSS-02, Rev. 0

SCOPE This Transmission Material Standard Specification (TMSS) specifies the minimum technical requirements for design, engineering, manufacture, inspection, testing and performance of porcelain and toughened glass suspension insulators intended to be used on the overhead transmission line system of Saudi Electricity Company (SEC), Saudi Arabia.

2.0

CROSS REFERENCES This Material Standard Specification shall always be read in conjunction with the latest revision of SEC General Specification No. 01-TMSS-01, titled "General Requirements for All Transmission Equipment/Materials", which shall be considered as an integral part of this TMSS. This TMSS shall also be read in conjunction with SEC Purchase Order or Contract Schedules for project, as applicable.

3.0

APPLICABLE CODES AND STANDARDS The latest revision/amendments of the following Codes and Standards shall be applicable for the equipment/material covered in this TMSS. In case of conflict, the vendor/manufacturer may propose equipment/material conforming to one group of Industry Codes and Standards quoted hereunder without jeopardizing the requirements of this TMSS. 3.1

IEC 60120

Dimensions of ball and socket couplings of string insulator units

3.2

IEC 60372

Locking Devices for ball and socket couplings of string insulator units - Dimensions and tests.

3.3

IEC 60383-1 Insulators for overhead lines with a nominal voltage above 1000V, Part 1: Ceramic or glass insulator units for a.c systems-Definitions, test method and acceptance criteria

3.4

IEC 60383-2 Insulators for overhead lines with a nominal voltage above 1000V, Part 2: Insulator strings and insulator sets for a.c systems Definitions, test methods and acceptance criteria

3.5

IEC 60507

Artificial pollution tests on high voltage insulators to be used on a.c. systems

3.6

IEC 61467

Insulators for overhead lines with a nominal voltage above 1000VAC power arc tests on insulator sets

3.7

IEC 61211

Insulators of ceramic material or glass for overhead lines with a nominal voltage greater than 1000V-Impulse puncture testing in air

3.8

ANSI C29.1

Test Methods for Electrical Power Insulators

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4.0

15-TMSS-02, Rev. 0

3.9

ANSI C29.2

Insulator, Wet-Process Porcelain and Toughened Glass, Suspension Type

3.10

ASTM C151 Test Method for Autoclave Expansion of Portland Cement

DESIGN AND CONSTRUCTION REQUIREMENTS 4.1

4.2

General 4.1.1

The wet-process aluminous porcelain or toughened glass suspension insulators shall meet or exceed the requirements of this specification in all respects.

4.1.2

The manufacturer’s design drawings, as required in 01-TMSS-01, shall show the outline of the suspension insulators, together with all pertinent dimensions. Any variations in these dimensions due to manufacturing tolerances shall be indicated.

Design Criteria 4.2.1

Service conditions referenced in 01-TMSS-01 shall be the basis of design criteria.

4.2.2

The wet-process aluminous porcelain or toughened glass insulator design shall be antifog, superfog, or aero form (open profile) type with ball and socket couplings. These shall be designed to withstand water jet pressure of 3800 kPa.

4.2.3

The ball and socket couplings of all insulators must be ANSI or IEC compatible.

4.2.4

The metal parts and the porcelain or glass parts shall be movable in relation to each other to avoid large mechanical stresses due to difference in coefficient of thermal expansion of the metallic parts, cement and the porcelain or glass materials. Thus, the metal cap shall move up and down, in an elastic manner under the external tension load, on the sloping surface of the adjacent cement. The metal pin shall act in the same manner.

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15-TMSS-02, Rev. 0


4.3

Ratings The wet-process aluminous porcelain or toughened glass suspension insulators shall have the minimum ratings as indicated in Table 1: Table 1: Minimum ratings for Insulators Fog/Super Fog (Porcelain and Toughened Glass)

Ratings

Combined Mechanical and Electrical (M&E) Strength, kN Tension Proof Load Low Frequency Flashover, kV Critical Impulse Flashover, kV

111/160/210*

Porcelain

Toughened Glass

111/160/210* 111/160/210*

50% of specified M&E Rating

Dry

95

80

65/75/75

Wet

55

50

50

Positive

135

105

95/105/105

Negative

145

105

95/105/105

Low Frequency Puncture Voltage, kV RIV Low Frequency Test Voltage (rms to ground), kV Maximum RIV at 1000kHz, µV Residual strength after maximum loadings * Refer to Data Schedule 4.4

Aero Form

110/110/125 10 50 70% of rated M&E

Materials All insulator shells shall be sound and free from defects that might adversely affect the insulator. Metal parts, except for cotter keys, shall be made of the best commercial grade of malleable iron, ductile iron or steel, galvanized in accordance with 01-TMSS-01. The thickness of zinc coating on the insulator caps and pins shall not be less than 0.110 mm (770 g/m²) and 0.053 mm (381 g/ m²) respectively. Insulators shall be furnished with a positive locking device of the split cotter key type. The cotter keys shall be made of bronze, brass or austenitic stainless steel. In addition, specific requirements as stated below shall be met.

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4.4.1

15-TMSS-02, Rev. 0

Porcelain Insulators: The insulator shells shall be made of the highest grade, dense, homogeneous wet-process aluminous porcelain. The entire exposed wet process aluminous porcelain surface of the insulator shell shall be glazed, relatively smooth and free from imperfections. The porcelain used shall be non-porous with high dielectric strength, chemically inert and high fusion point. The color of the porcelain glaze shall be brown and of uniform coverage and thickness. Portland cement or Alumina cement shall be used as the bonding agent between the wet-process porcelain and the metal parts. Sulfur based cements shall not be used.

4.4.2

Toughened Glass Insulators The entire glass surface of the insulator shell shall be toughened, smooth and free from imperfections. The toughened glass used, shall have no surface defects such as folds, blowholes, prejudicial to satisfactory performance in service and there shall be no bubbles in the glass greater than 5 mm in diameter. Aluminous cement mortar shall be used as the bonding agent between the toughened glass and the metal parts. Portland cement mortar may also be used as the bonding agent but sulfur based Portland cements shall not be used.

4.5

Fabrication 4.5.1

The hardware shall be cemented on the porcelain or glass with load distribution evenly throughout the porcelain or glass. Before cementing, the hardware surface in contact with the cement shall be coated with bituminous compound.

4.5.2

The contours of the metal and porcelain or glass parts shall be such as to eliminate areas of high electrical stress concentrations.

4.5.3

The axial, radial and angular displacements of the Insulator and their verification shall be in accordance with IEC 60383-1

4.5.4

To inhibit the accelerated corrosion of insulator pin due to leakage currents, a corrosion intercepting zinc sleeve fused to the pin shall be provided at the point where the steel pin emerges from the cement.

4.5.5

Cotter keys shall be humped to maintain the key in the locked and unlocked positions and shall have prongs spread to prevent complete withdrawal from the socket. The design of the keys shall be such that their engagement

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15-TMSS-02, Rev. 0


and disengagement can be achieved with the use of standard transmission hot line tools without excessive force required.

4.6

4.5.6

For 111kN insulators, ball and socket couplings shall be Type J as per ANSI C29.2 or Size 16A as per IEC 60120.

4.5.7

For 160kN and 210kN insulators, ball and socket couplings shall be Type K as per ANSI C29.2 or Size 20 as per IEC 60120.

Dimensions The dimensions of the suspension insulators shall be as specified in Data Schedule and as shown in the Table 2: Table 2 Minimum Leakage Distance (mm) Super Aero Fog Fog Form

Maximum Shell Diameter (mm) Super Aero Fog Fog Form

Nominal Spacing Distance (mm) Super Aero Fog Fog Form

111

432

280

146

111

545

330

146

160

432

300

156

160

545

-

335

330

-

420

210

545

-

335

330

-

420

Minimum M&E Strength (kN)

Note:

4.7

612

335

330

380

146

146

156

-

156

170

-

170

While replacing insulators on existing transmission lines it must be ensured that adequate clearances to tower/ground are maintained.

Markings 4.7.1

Each wet-process porcelain or toughened glass insulator shall bear a durable marking in accordance with IEC or ANSI Standards, identifying the following: a. b. c. d. e.

4.7.2

Crate or Pallet Marking (whichever is applicable) a. b.

15TMSS02R0/MAA

Manufacturer's Name Year of Manufacture Combined Mechanical and Electrical Strength, "M & E" Tension Proof Test Load, "TEST" Country of Origin

Insulator Shell (Porcelain/Toughened Glass) Insulator Type (Fog/Super Fog/Aerodynamic)


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c. d. e. f.

15-TMSS-02, Rev. 0

SEC Purchase Order Number/Contract Number 15-TMSS-02, Rev.0 Manufacturer’s Catalog No. Number of insulators in the Crate and the Pallet

The markings shall be legible and durable.

5.0

TESTS All test results shall be provided for review and acceptance by SEC. 5.1

Type (Design) Tests All type (design) tests prescribed in the relevant IEC or equivalent ANSI standards shall be performed on the representative unit or on the first unit of every new design or rating to be supplied to SEC. In lieu of the actual design (type) tests, certified test reports of design (type) tests performed on a unit of identical design and rating may be submitted to SEC for review and approval during bidding stage. In addition to the above IEC or ANSI type test requirements, the following type tests shall be carried out on the insulators to be supplied under these specifications. The tests shall be performed at manufacturer’s own laboratory in the presence of SEC representative or at an accredited Independent Testing Laboratory. The test results shall be considered valid for a period of five years only, after which these tests shall be repeated in case of any further supply from the same manufacturer and from the same manufacturing plant. These tests may also be repeated at any time within a five years period, if SEC considers it necessary for a particular project as specified in Data Schedule. 5.1.1

Thermal Mechanical Performance Test on string insulator units in accordance with IEC 60383-1 except that the temperature variation shall o be minus five degrees centigrade (-5 C) to plus sixty five degrees o centigrade (+65 C).

5.1.2

Steep Front-of-Wave Flashover Test: Ten (10) insulator units selected at random from the first production lot shall be subjected to five successive positive and negative impulse flashover with a wave front having a minimum effective rate of rise of 2500 kV per microsecond. Each of the ten (10) insulators shall be individually tested. Each unit shall then be subjected to the rated low-frequency dry flashover test (five successive flashovers). No electrical puncture shall occur, and the flashover arc must be external. The failure of any one unit either in the front-of-wave or subsequent low frequency withstand voltage test shall require testing an additional 20

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15-TMSS-02, Rev. 0


units. Failure of more than one unit from the total so tested shall constitute failure to meet the requirements of this specification. 5.1.3

Power Arc Follow Through Test: Ten (10) insulators shall be selected at random from the first production lot. Each unit from the ten insulators shall be attached to the lower end of a vertical string of five other units. Each string of six insulators shall be subjected to two flashovers of 6,000 A for 12 cycles. The 60 Hz voltage shall be applied to the bottom of the string with ground at the top of the string. The insulators shall be stressed to 40 % of rated strength of the insulator. The flashover shall be initiated by a fuse wire connected from the cap of the top insulator to the pin of the bottom insulator. The insulators shall be operationally safe after the conclusion of the test and shall meet the following criteria: i.

There shall be no porcelain/glass body.

separation

of

metal

components

from

ii.

The insulators shall not have an electrical puncture and the flashover shall be external when subjected to dry flashover test.

iii. The mechanical strength of insulators shall not be reduced below 80 % of their rated M & E strength. Failure of any one unit in the test shall be the cause for testing another ten (10) insulators. Failure of more than one unit from the total so tested shall constitute failure of the insulator design to meet the requirements of the specification. 5.1.4

Autoclave Expansion Test for Portland Cement- The soundness of Portland Cement to be used as the bonding agent for wet-process aluminous porcelain or toughened glass insulators shall be tested in accordance with the ASTM C151. Ten (10) samples of cement for the test specimen shall be selected at random from the batch to be used for insulators. The bars prepared from neat cement when subjected to high-pressure steam at 2 ± 0.07 MPa for three hours at 216°C shall not show expansion of more than 0.12 percent. The expansion of cement more than 0.12 percent in the test shall be the cause for rejection of the whole batch of cement.

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5.2

15-TMSS-02, Rev. 0

Routine (Production) Tests All routine (production) tests prescribed in the relevant IEC or equivalent ANSI standards shall be performed on all units prior to delivery to SEC.

5.3

Sample (Quality Conformance) Tests All sample (quality conformance) tests prescribed in the relevant IEC and ANSI standards shall be performed on each lot of insulator prior to delivery to SEC. In addition to the above IEC or ANSI sample test requirements, the following sample tests shall be carried out:

5.4

5.3.1

A dimension test shall be performed on three strings of six insulators each selected at random and the connecting length of each string shall be 6 times the nominal spacing of the insulators with a tolerance of ± 19 mm.

5.3.2

Verification of axial, radial, and angular displacement.

Special Tests The pollution test, as an option shall be performed in accordance with IEC 60507, if requested by SEC in Data Schedule.

5.5

Acceptance Criteria 5.5.1

The acceptance criteria of the specified number of insulators tested shall be in accordance with ANSI C29.2 or IEC 60383, except for Thermal Mechanical Performance Test and Mechanical & Electrical Failing Load Tests.

5.5.2

The acceptance criteria for Thermal-Mechanical Performance Test and Mechanical & Electrical Failing Load Tests shall be as specified below: a.

The result of the Thermal-Mechanical Performance test shall match the result of the ordinary M&E failing load tests.

b.

Each measured value shall not be less than the specified M&E Strength + 3σ.

c.

Electrical puncture shall not occur before the ultimate fracture.

d.

The acceptance constant, k shall be equal to or greater than 3; 3 ≤ k = X - Xs σ

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where

15TMSS02R0/MAA

X = Xs = σ =

15-TMSS-02, Rev. 0

Mean value M&E rated value Standard deviation


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15-TMSS-02, Rev. 0


6.0

DATA SCHEDULE

SUSPENSION TYPE INSULATORS SEC Enquiry No.

Date:

SEC Purchase Order No. or Contract No.

Date:

SEC PTS No./Project Title with J.O. No. REFERENCE SECTION NO.

3.0

DESCRIPTION

'A'

'B'

'C'

APPLICABLE CODES AND STANDARDS Applicable Industry Standards

*

4.0

DESIGN AND CONSTRUCTION REQUIREMENTS

4.1

Insulator Material and Type Porcelain/Toughened Glass Fog/Super Fog/Aero Form

4.3

Ratings Combined Mechanical and Electrical Strength (kN) (111kN/160kN/210kN) Tension proof load (kN) (55.5kN/80kN/105kN) Electrical Values (Porcelain Insulators) Low frequency dry flashover (kV) (95kV/80kV)

*

'A'- SEC SPECIFIED DATA/PARAMETERS 'B'- BIDDER/SUPPLIER/VENDOR/CONTRACTOR PROPOSED DATA/PARAMETERS 'C'- REMARKS SUPPORTING THE PROPOSED DEVIATION IN COLUMN 'B'. (*)- DATA/PARAMETERS TO BE PROVIDED/PROPOSED BY THE BIDDER/SUPPLIER/ VENDOR/CONTRACTOR IN COLUMN 'B'

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15-TMSS-02, Rev. 0


6.0

DATA SCHEDULE

SUSPENSION TYPE INSULATORS

REFERENCE SECTION NO.

DESCRIPTION

'A'

Low frequency wet flashover (kV) (55kV/50kV)

*

Critical impulse flashover, Positive (kV) (135kV/105kV)

*

Critical impulse flashover, negative (kV) (145kV/105kV)

*

'B'

'C'

Electrical Values (Glass Insulators) Low frequency dry flashover (kV) (95kV/75kV/65kV)

*

Low frequency wet flashover (kV) (55kV/50kV)

*

Critical impulse flashover, Positive (kV) (135kV/105kV/95kV)

*

Critical impulse flashover, negative (kV) (145kV/105kV/95kV)

*

Low frequency puncture Voltage (kV)

110/110/125

RIV low frequency test voltage (rms to ground) (kV)

10

Maximum RIV at 1000 KHz (µV) Weight per unit (kg)

15TMSS02R0/MAA

50µV *


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15-TMSS-02, Rev. 0


6.0

DATA SCHEDULE

SUSPENSION TYPE INSULATORS

REFERENCE SECTION NO.

DESCRIPTION

4.4

Color for Aluminous porcelain

4.6

Dimension:

'A'

'B'

'C'

Brown Glaze

Coupling type (ANSI size J/K) (IEC size 16A/20) Leakage distance per unit (mm)

*

Shell diameter (mm)

*

Spacing distance (mm)

*

5.0

TYPE TESTS

5.1

Are additional type tests required? Are additional type tests performed?

5.4

Yes/No *

Yes/No

SPECIAL TESTS Is Pollution test required? Is Pollution test performed?

15TMSS02R0/MAA

Yes/No *


Yes/No

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15-TMSS-02, Rev. 0


6.0 DATA SCHEDULE SUSPENSION TYPE INSULATORS A.

ADDITIONAL TECHNICAL INFORMATION OR FEATURES TO BE FURNISHED BY SEC:

B.

ADDITIONAL SUPPLEMENTARY DATA OR BIDDER/VENDOR/SUPPLIER/CONTRACTOR:

B.

OTHER PARTICULARS TO BE FILLED UP BY BIDDER/VENDOR/SUPPLIER/ CONTRACTOR:

FEATURES

Actual Manufacturer of Equipment/Material

PROPOSED

BY

Vendor/Supplier/ Contractor

Name of the Company Location and address

Name and Signature of authorized representative and date

Official Seal/Stamp of the Company & Date

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15-TMSS-02-R0

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