Externally mounted bushing current transformers are designed for use on existing power transformers or circuit breakers for relaying purposes. Installation time is minimum since it is not necessary to remove bushings or open the tank for mounting.

The transformers and brackets shown below are for use with standard ANSI bushings.

It is recommended that the power transformer or circuit breaker manufacturer be checked prior to installation to determine if the bushing strike distance is affected by installation of a bushing current transformer.

Bushing current transformer core and coil assemblies are housed in an aluminum case, which is filled with polyurethane.

The aluminum case has a shielding effect, protecting the winding in case of bushing flashover.

Installation Notes:

• A secondary junction box with three conduit fittings is standard on every unit

• Remove bushing flange nuts - (4 total as shown) and assemble mounting brackets

• Remove bushing gaps to allow clearance for lowering current transformer over bushing

• Maintain 3/8” clearance between current transformer housing and bushing tap socket

• Caution: when mounting current transformer, care must be taken to see that the inside wall of the current transformer clears and does not touch any metal parts of bushing or mounting, so as not to complete a ground circuit around current transformer housing

• Maximum K (bushing shed diameter) is F - 1/8

• Maximum L (for voltage tap socket clearance) is F/2 - 3/8

• Minimum M (bushing flange height) is J + 1/4