Wiring, Cable workmanship guidelines – Rockwell Automation 294D ArmorStart LT Distributed Motor Controller DeviceNet Version - User Manual User Manual
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Rockwell Automation Publication 290D-UM001A-EN-P - June 2012
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Installation and Wiring
Chapter 2
Group Motor Installations for
USA and Canada Markets
When ArmorStart LT is applied according to group motor installation
requirements, two or more motors of any rating or controller type, are permitted
on a single branch circuit. Group Motor Installation has been successfully used
for many years in the USA and Canada.
Wiring
Cable Workmanship Guidelines
In addition to conduit and seal-tite raceway, it is acceptable to utilize cable that is
dual rated Tray Cable Exposed Runs (TC-ER) and Cord, STOOW, for power
and control wiring on ArmorStart LT installations. In the USA and Canada
installations, the following guidance is outlined by the National Electrical Code
(NEC) and National Fire Protection Association (NFPA) 79.
In industrial establishments where the conditions of maintenance and
supervision ensure that only qualified persons service the installation, and where
the exposed cable is continuously supported and protected against physical
damage using mechanical protection, such as struts, angles, or channels, Type TC
tray cable that complies with the crush and impact requirements of Type MC
(Metal Clad) cable and is identified for such use with the marking Type TC-ER
(Exposed Run)➊ shall be permitted between a cable tray and the utilization
equipment or device as open wiring. The cable shall be secured at intervals
not exceeding 6 ft (1.8 m) and installed in a “good workman-like” manner.
Equipment grounding for the utilization equipment shall be provided
by an equipment grounding conductor within the cable.
While the ArmorStart LT is intended for installation in factory floor
environments of industrial establishments, the following must be taken into
consideration when locating the ArmorStart LT in the application:
•
Cables, including those for control voltage including 24V DC and
communications, are not to be exposed to an operator or building traffic
on a continuous basis.
•
Location of the ArmorStart LT to minimize exposure to continual traffic
is recommended. If location to minimize traffic flow is unavoidable, other
barriers to minimize inadvertent exposure to the cabling should be
considered.
•
Routing cables should be done in such a manner to minimize inadvertent
exposure and/or damage.
•
If conduit or other raceways are not used, it is recommended that strain
relief fittings be utilized when installing the cables for the control and
power wiring through the conduit openings.
➊ Historically cable meeting these crush and impact requirements was designated and marked “Open Wiring.” Cable so marked is
equivalent to the present Type TC-ER and can be used.
IMPORTANT
For additional information regarding group motor installations with the
ArmorStart LT Distributed Motor Controller, see