Chapter 5 - installing input power wiring, 0 installing input power wiring, 1 installing transformers and reactors (optional) – Rockwell Automation GV3000 AC Pwr Module Ver. 5.0 Hardware Ref, Installation, and Troubleshooting User Manual

Page 49: 2 installing fuses for branch circuit protection

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5Ć1

5.0 INSTALLING INPUT POWER WIRING

This chapter describes incoming line components and how to install them.

5.1 Installing Transformers and Reactors (Optional)

Input isolation transformers might be needed to help eliminate the following:
D Damaging line voltage transients from reaching the drive.
D Line noise from the drive back to the incoming power source.
D Damaging currents that could develop if a point inside the drive becomes grounded.
Observe the following guidelines when installing an isolation transformer:
D A power disconnecting device must be installed between the power line and the primary of the

transformer.

D If the power disconnecting device is a circuit breaker, the circuit breaker trip rating must be

coordinated with the inĆrush current (10 to 12 times full load current) of the transformer.

D An input isolation transformer rated more than 1000 KVA for 460 VAC with less than 5%

impedance should NOT be used directly ahead of the drive without additional impedance

between the drive and the transformer.

CAUTION: Distribution system capacity above the maximum recommended system KVA (1000 KVA for

460 VAC) requires the use of an isolation transformer, a line reactor, or other means of adding similar impedĆ

ance to the drive power input. Failure to observe these precautions could result in damage to or destruction

of the equipment.

CAUTION: When the AĆC line is shared directly with other SCRĆrectified drives, an optional snubber resistor

braking kit might be required to alleviate excess DĆC 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, userĆsupplied branch circuit protection fuses according to NEC/CEC guidelines.

The fuses must be 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.

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