Rockwell Automation 1336T Wiring and Grounding Guide, (PWM) AC Drives - Manual (Page 11)

Rockwell Automation Publication DRIVES-IN001M-EN-P - March 2014 11
Chapter
1
Wire/Cable Types
AC drive installations have specific wire and cable requirements. This section
includes information about the major issues for proper selection of cable, and
provides recommendations to address these issues. Consider these conditions and
requirements when choosing cable material and construction for your
installation:
• Environment – such as moisture, temperature, and harsh or corrosive
chemicals.
• Mechanical needs – such as geometry, shielding, flexibility, and crush
resistance.
• Electrical characteristics – such as cable capacitance/charging current,
resistance/voltage drop, current rating, and insulation. Insulation can be
the most significant of these. Because drives can create voltages in excess of
line voltage, the industry standard cables that were used in the past are not
the best choice for variable speed drives. Drive installations benefit from
cable that is significantly different than cable used to wire contactors and
push buttons.
• Safety issues – such as electrical code requirements, grounding needs, and
others.
Choosing incorrect cabling can be costly and can adversely affect the
performance of your installation.
General Material
Use only copper wire. The wire clamp-type terminals in Allen-Bradley drives are
made for use with copper wire. If you use aluminum wire, the connections can
loosen and cause premature equipment failure.
Wire gauge requirements and recommendations are based on 75 °C (167 °F)
rating. Do not reduce wire gauge when you use higher temperature wire.
Exterior Cover
Whether shielded or unshielded, the cable must meet all of the application
requirements. Consider insulation value and resistance to moisture,
contaminants, corrosive agents, and other invasive elements. Consult the cable
manufacturer and
Figure 1 on page 12 for cable selection criteria.