CT/PT Metering Sets

INTRANS 11KV CT/PT UNITS

INTRANS 11KV/ 22KV/ 33KV CT/PT UNITS (HT metering sets) consists of two Current Transformers and one Three phase Voltage Transformer each with an accuracy class 0.5. These are oil immersed, in a mild steel tank and are suitable for out door platform mounting or pole mounting use.

CURRENT TRANSFORMERS

Current Transformers are Epoxy Resin moulded. The windings and core are completely embedded in quartz loaded Epoxy Resin by using vacuum moulding technique and are then hardened by polymerisation. The Current Transformers have high mechanical and dielectric properties and require no maintenance.

VOLTAGE TRANSFORMER

The Voltage Transformer is oil immersed type. The magnetic circuit of the three leg core type made up from Cold rolled Grain Oriented Grade 41 silicon steel laminations. These cores are liberally designed as regards flux density thus avoiding abrupt changes of error with slight excess voltage. The core clamps are of angle iron construction.
The low voltage winding consists of a single coil for each leg. The high voltage winding is built up from a number of separate coils, the line coils having reinforced end turn insulation. All coils are thoroughly dried and impregnated with varnish. Both primary and secondary windings are star connected.

FUSES

Three high voltage HRC PT fuses of 2 amps cap and two bakelite HRC fuse units are fitted. The former are located in the tank on a specially moulded epoxy fuse carrier which can be easily reached by removing the top HT fuse cover. The latter are situated in secondary terminal box.

SECONDARY TERMINAL BOX

The secondary terminals are brought out of the tank through a moulded epoxy terminal board with brass terminals with M6 threads. The bakelite fuse holder with HRC fuses are mounted on this terminal board.

OUTPUT RATING

The epoxy molded current transformers have, secondary windings rated at 5 amps with accuracy class 0.5 as per IS 2705. The three phase voltage transformer is designed for 110V between secondary terminals as per IS 3156. The transformers are designed to have their specific output and accuracy at 50 cycles per second.

Special Features

INTRANS Metering sets for outdoor use have the following special features.

» The transformers are housed in a sheet steel welded tank. These tanks are pretreated with 7 tank phosphating process and stove enamelled. The transformers are housed in a sheet steel welded tank. These tanks are pretreated with 7 tank phosphating process and stove enamelled.
» A gradual slope on the tank top cover ensures that no rain water accumulates on the cover.
» The secondary terminals are located in a box welded on one side of the tank with provision for sealing.
» Lifting lug, drain plug, oil filling plug, oil level indicator and earthing terminals are provided as standard fittings.
» Epoxy resin moulded Current Trainsformers enable withstanding of dynamic forces during short circuit conditions.

Complete conformation to all the relevant Indian Standard Specifications.