Chapter 5 Installing Input Power Wiring; Installing Transformers And Reactors (Optional) - Reliance electric GV3000/SE Hardware Reference, Installation, And Troubleshooting Manual

5.1 Installing Transformers and Reactors (Optional)

Installing Input Power Wiring
This chapter describes incoming line components and how to install them.
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.
•
For drives equipped with an AC Mains Filter, 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.
•
For drives not equipped with an AC Mains Filter, an input isolation transformer rated
more than 315 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.
ATTENTION: Distribution system capacity above the maximum
recommended system KVA (1000 KVA for 460 VAC for drives equipped
!
with an AC Mains Filter, 315 KVA for 460 VAC for drives not equipped
with an AC Mains Filter) requires the use of an isolation transformer, a
line reactor, or other means of adding similar impedance to the drive
power input. Failure to observe these precautions could result in damage
to, or destruction of, the equipment.
ATTENTION: When the AC line is shared directly with other
SCR-rectified drives, an optional snubber resistor braking kit might be
required to alleviate excess DC bus voltage. Failure to observe these
precautions could result in damage to, or destruction of, the equipment.
For drives equipped with an AC Mains Filter, the maximum AC line distribution system
capacity is 1000 KVA, three-phase with 30,000 amps symmetrical fault current
capacity with a line impedance of less than 5%.
Installing Input Power Wiring
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