3 installing input isolation transformers – Rockwell Automation VSM500 Integrated Drive/Motor User Manual

Page 24

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4-2

Installing and Operating the VSM500 Integrated Drive/Motor, Version 3.0

4.3

Installing Input Isolation Transformers

Depending upon the requirements of the application, the VSM500 unit may require
input isolation transformers to help eliminate the following:

Damaging AC line voltage transients from reaching the VSM500 unit.

Line noise from the VSM500 unit being fed back to the incoming power source.

An isolation transformer or line reactors of 3% drive input impedance should be used
between the distribution source and the VSM500 unit in situations such as the
following:

The power distribution system feeding the VSM500 unit contains power factor
correction capacitors.

The power distribution system feeding the VSM500 unit connects with heavy
industrial equipment that causes instantaneous line distribution shorts such as arc
welders, line-commutated thyristor converters, or line-started AC induction motors
greater than 50 HP (37 KVA).

The distribution transformer is rated more than 100 KVA for 460 VAC with less than
5% impedance.

The distribution system is prone to frequent power outages or transient power
interruptions or significant voltage spikes.

Refer to table 4.2 for the appropriate line reactor for your unit.

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.

!

ATTENTION: Distribution system capacity above the maximum
recommended system KVA (100 KVA for 460 VAC three-phase, 5%
impedance) requires using an isolation transformer, a line reactor, or
other means of adding similar impedance. Failure to observe this
precaution could result in damage to, or destruction of, the equipment.

Table 4.2 – Input Line Reactors

VSM500 Unit

Input Line Reactor

HP

Input Voltage

Inductance

Rated
Amps

Reliance Part No.

1

460V, 3-Phase

6.5 mH

4.0

608895-63D

2

460V, 3-Phase

3.0 mH

8.0

608895-63F

3

460V, 3-Phase

2.5 mH

12.0

608895-63H

5

460V, 3-Phase

1.5 mH

18.0

608895-63K

1

230V, 3-Phase

1.5 mH

8.0

608895-63E

2

230V, 3-Phase

0.8 mH

18.0

608895-63J

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