Transforador De Corriente

CEB STANDARD 039 : 1998

Specification for

CURRENT TRANSFORMER TEST BENCH

CEB Standard 039 : 1998

CEYLON ELECTRICITY BOARD

No. 50, Sir Chittampalam A. Gardiner Mawatha, Colombo 2. Sri Lanka

Telephone: 24471-8

Telex : 21368 CE Facsimile: 94-1-449572 E-mail : cebdp@mega.lk

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CEB STANDARD 039 : 1998

CONTENTS Page 1 2. 3. 4. 5. 6. 7. 8. 9. 10. Scope System ParametersService Conditions Technical Requirements Basic Features Additional Requirements Information to be supplied with the Offer Inspection & Testing Technical Literature & Drawings Annexure 5 6 6 6 6 2 2 3 2 2

SPECIFICATION FOR CURRENT TRANSFORMER TEST BENCH
1.0 SCOPE
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CEB STANDARD 039 : 1998

This Specification covers the general requirements of the design, manufacture and testing of fullyAutomatic Current Transformer Test Bench. 2.0 SYSTEM PARAMETERS (a) (b) (c) (d) 3.0 Nominal System Voltage System Highest Voltage System Frequency Method of earthing 400/230 V,3 ph & Neutral 440/250 V,3 ph & Neutral 50 Hz Solidly earthed Neutral at substations

SERVICE CONDITIONS (a) (b) (c) (e) (f) Annual average ambient temperature Maximum ambient air temperature Maximum relative HumidityEnvironmental condition Operational Altitude 30°C 40°C 90% Humid tropical climate with polluted atmosphere From M.S.L. to 1900 metes above M.S.L..

4.0

APPLICABLE STANDARD The Current Transformer (CT) Test bench supplied shall be in accordance with the later editions of the Standard specified below and amendments thereof. a) b) c) d) IEC 185 (1987) IEC 1010-1 (1980) IEC 348 (1978) IEC 529 CurrentTransformer. Safety requirements for electrical equipment for measurement control and laboratory use. Safety requirements apparatus. for electronic measuring

Degree of protection provided by the enclosure.

The Test Bench conforming to any other international standards which are equal to or higher but not less rigid than the Standards and Specifications stipulated may be offered. When suchalternative Standards are used reference to such Standards shall be quoted and English Language copies of such standards shall be furnished with the offer. Failure to do so will result in the offer being rejected. 5.0 BASIC FEATURES 5.1 5.1.1 Basic Features The CT Test Bench shall be of the fully automatic type suitable for testing low voltage ring (bar primary) type measuring current transformerswhich are used with 400/230V 50Hz. 3 phase 4 wire kWh energy meters and wound primary type
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CEB STANDARD 039 : 1998

medium voltage (12kV/36kV) measuring and protection type current transformer. The Test Bench shall conform to the Standards specified above. 5.1.2 The CT Test Bench shall be suitable for testing CT manufactured in accordance to IEC 185 of 1987 and shall be suitable for testingsingle ratio/double ratio current transformers of accuracy class 2, 5 & 1 and of burden up to 15 VA. The CT Test Bench shall be suitable to carry out precise measurement of ratio and phase angle error. The ratio error and phase angle error of the CT under test shall be compared with specified limit as mentioned in the IEC 185 or defined by the operator also. These errors and status of CT undertest (pass/fail) shall be displayed on the computer screen. The test duration for each point shall not be more than 10 sec. Current rise per second shall be programmable. The Test bench shall have the facilities to carry out inter-turn insulation test on the secondary winding automatically as per IEC 185 (1987). Necessary peak voltmeter and capacitor shall be provided to indicate the test voltage.Safety measures shall be incorporated to prevent inducing high voltage in the secondary winding 5.1.4 The CT Test Bench shall have Automatic Current generation and voltage regulating unit, Standard CT, Standard burden, PC, Printer, Testing software and Connecting cables. All connecting cables required for testing (Secondary leads) shall be duly calibrated. 1) Automatic Current generation and...