User Manual

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