22 Rockwell Automation Publication 520-TD002A-EN-E - May 2015
PowerFlex 527 AC Drive Specifications
Shielded/Armored Cable
Shielded cable contains all of the general benefits of multi-conductor cable with the added benefit of a copper braided
shield that can contain much of the noise generated by a typical AC Drive. Strong consideration for shielded cable should
be given in installations with sensitive equipment such as weigh scales, capacitive proximity switches and other devices that
may be affected by electrical noise in the distribution system. Applications with large numbers of drives in a similar
location, imposed EMC regulations or a high degree of communications / networking are also good candidates for shielded
cable.
Shielded cable may also help reduce shaft voltage and induced bearing currents for some applications. In addition, the
increased impedance of shielded cable may help extend the distance that the motor can be located from the drive without
the addition of motor protective devices such as terminator networks. Refer to Reflected Wave in “Wiring and Grounding
Guide, (PWM) AC Drives,” publication DRIVES-IN001
.
Consideration should be given to all of the general specifications dictated by the environment of the installation, including
temperature, flexibility, moisture characteristics and chemical resistance. In addition, a braided shield should be included
and be specified by the cable manufacturer as having coverage of at least 75%. An additional foil shield can greatly improve
noise containment.
A good example of recommended cable is Belden® 295xx (xx determines gauge). This cable has four (4) XLPE insulated
conductors with a 100% coverage foil and an 85% coverage copper braided shield (with drain wire) surrounded by a PVC
jacket.
Other types of shielded cable are available, but the selection of these types may limit the allowable cable length. Particularly,
some of the newer cables twist 4 conductors of THHN wire and wrap them tightly with a foil shield. This construction can
greatly increase the cable charging current required and reduce the overall drive performance. Unless specified in the
individual distance tables as tested with the drive, these cables are not recommended and their performance against the lead
length limits supplied is not known.
Reflected Wave Protection
The drive should be installed as close to the motor as possible. Installations with long motor cables may require the addition
of external devices to limit voltage reflections at the motor (reflected wave phenomena). Refer to Reflected Wave in
“Wiring and Grounding Guide, (PWM) AC Drives,” publication DRIVES-IN001
.
The reflected wave data applies to all carrier frequencies 2...8 kHz.
For 240V ratings and lower, reflected wave effects do not need to be considered.
Recommended Shielded Wire
Location Rating/Type Description
Standard (Option 1) 600V, 90 °C (194 °F) XHHW2/RHW-2
Anixter B209500-B209507, Belden 29501-29507, or equivalent
• Four tinned copper conductors with XLPE insulation.
• Copper braid/aluminum foil combination shield and tinned copper drain wire.
• PVC jacket.
Standard (Option 2) Tray rated 600V, 90 °C (194 °F)
RHH/RHW-2 Anixter OLF-7xxxxx or equivalent
• Three tinned copper conductors with XLPE insulation.
• 5 mil single helical copper tape (25% overlap min.) with three bare copper grounds in
contact with shield.
• PVC jacket.
Class I & II;
Division I & II
Tray rated 600V, 90 °C (194 °F)
RHH/RHW-2 Anixter 7V-7xxxx-3G or equivalent
• Three bare copper conductors with XLPE insulation and impervious corrugated
continuously welded aluminum armor.
• Black sunlight resistant PVC jacket overall.
• Three copper grounds on #10 AWG and smaller.
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