Chapter 5 - installing input power wiring, Hapter, Installing input power wiring – Rockwell Automation Liqui-Flo AC Power Modules User Manual

Page 51

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Installing Input Power Wiring

5-1

C

HAPTER

5

Installing Input Power Wiring

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

5.1

Installing Transformers and Reactors (Optional)

The LiquiFlo AC drive may be used on distribution systems with 85,000 amps or less
symmetrical fault current capacity. Line reactors are not needed for safe operation of
the drive but may be required to reduce line harmonics.

Input isolation transformers might be needed to help eliminate the following:

Damaging line voltage transients from reaching the drive.

Line noise from the drive back to the incoming power source.

Damaging currents that could develop if a point inside the drive becomes grounded.

Observe the following guidelines when installing an isolation transformer:

A power disconnecting device must be installed between the power line and the
primary of the transformer.

If 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.

5.2

Installing Fuses for Branch Circuit Protection

Install the required, user-supplied branch circuit protection fuses according to the
applicable local, national, and international codes (e.g., NEC/CEC). 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 3.7.

!

ATTENTION: Most codes require 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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