Rockwell Automation Publication 20A-IN009E-EN-P - January 2015 23
PowerFlex 70 Adjustable Frequency AC Drive
RFI Filter Grounding
If you use an optional radio-frequency interference (RFI) filter, relatively high
ground leakage currents can be present. Be sure that the incoming supply neutral
is solidly connected (bonded) to the same building power distribution ground.
Grounding must not rely on flexible cables and must not include any form of plug
or socket that permits inadvertent disconnection. Some local codes require
redundant ground connections. Periodically check the integrity of all
connections. See the instructions supplied with the filter
.
Power Wiring
Cable Types Acceptable for 200…600V Installations
Various cable types are acceptable for drive installations. For many installations,
unshielded cable is adequate as long as the cable is separated from sensitive
circuits. As an approximate guide, provide a spacing of 0.3 m (1 ft) for every 10 m
(32.8 ft) of length. In all cases, do not use long parallel runs. Do not use cable
with an insulation thickness less than 15 mils (0.4 mm/0.015 in.). Use copper
wire. Wire gauge requirements and recommendations are based on 75 °C (167
°F). Do not reduce wire gauge when using higher temperature wire.
Unshielded
Thermoplastic High Heat-resistant Nylon-coated (THHN), Thermoplastic
Heat and Water-resistant Nylon-coated (THWN), or similar wire is acceptable
for drive installation in dry environments as long as adequate free air space and/or
conduit fill rate limits are provided. The wire must have a minimum insulation
thickness of 15 mils (0.4 mm/0.015 in.) and cannot have large variations in
insulation concentricity.
Use RFI filters only in installations with grounded AC supply systems that are
permanently installed and solidly grounded (bonded) to the building power
distribution ground.
ATTENTION: The PowerFlex 70 does not provide branch short circuit
protection. See Drive, Fuse, and Circuit Breaker Ratings on page 25
for the
recommended fuse or circuit breaker to protect against short circuits.
ATTENTION: National Codes and standards (NEC, VDE, BSI, and others) and
local codes outline provisions for safely installing electrical equipment.
Installation must comply with specifications regarding wire types, conductor
sizes, branch circuit protection and disconnect devices. Failure to do so can
result in personal injury and/or equipment damage.
Do not use THHN or similarly coated wire in wet areas.
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