Installing Input Power Wiring; Installing Transformers And Reactors (Optional); Installing Fuses For Branch Circuit Protection - Reliance electric GV3000 Instruction Manual

5.0 INSTALLING INPUT POWER WIRING
This chapter describes incoming line components and howto install them.
5.1. Installing Transformers and Reactors (Optional)
Input isolation transformers might be needed to help eliminate the following:
e Damaging line voltage transients from reaching the drive.
e Line noise from the drive back to the incoming power source.
@ Damaging currents that could develop if a point inside the drive becomes grounded.
Observethe following guidelines when installing an isolation transformer:
e A power disconnecting device must be installed between the power line and the primary of the
transformer.
@ lf the power disconnecting device is a circuit breaker, the circuit breaker trip rating must be
coordinated with the in-rush current (10 to 12 times full load current) of the transformer.
@ An input isolation transformer rated more than 1000 KVAfor 460 VAC with less than 5%
impedance should NOT be used directly ahead of the drive without additional impedance
between the drive andthe transformer.
CAUTION: Distribution system capacity above the maximum recommended system KVA (1000 KVA for
460 VAC) requires the use of anisolation transformer, a line reactor, or other means of adding similar imped-
anceto the drive powerinput. Failure to observe these precautions could result in damage to or destruction
of the equipment.
CAUTION: Whenthe A-C line is shared directly with other SCR-rectified drives, an optional snubberresistor
braking kit might be required to alleviate excess D-C bus voltage. Failure to observe these precautions could
result in damage to or destruction of the equipment.
5.2 Installing Fuses for Branch Circuit Protection
Install the required, user-supplied branchcircuit protection fuses according to NEC/CEC guidelines.
The fuses mustbe installed in the line before the drive input terminals. See figures 5.1 and 5.2. Fuse
value selections are provided in table 3.9.
WARNING
THE NEC/CEC REQUIRES THAT UPSTREAM BRANCH PROTECTION BE PROVIDED TO PROTECT
INPUT POWER WIRING. FAILURE TO OBSERVE THIS PRECAUTION COULD RESULT IN SEVERE
BODILY INJURY OR LOSS OF LIFE.