Motor Cable Recommendations
D-1
A
PPENDIX
D
Motor Cable Recommendations
D.1 Drive-to-Motor Cable Distance
The cable distance between the drive and motor is limited for the following three
reasons:
1.
Long drive-to-motor cables can produce peak voltages that can damage motors
having an electrical insulation system less than that of MG-1 (1600 V). The use of
output line reactors can affect the limit. Use the table on the following page to
determine the maximum distance that may be applied with a non MG-1 motor (for
example, a motor with an insulation of 1000 V peak).
2.
Long drive-to-motor cables also produce current that is capacitively coupled to
ground. This can cause the drive to fault and misrepresent the cause. The use of
output line reactors and cable shields or conduit can affect the limit. Use the table
on the following page to determine the maximum distance under which the SP200
drive may be applied.
3.
Long drive-to-motor cables produce electromagnetic noise which affects the
system EMC compatibility. When compliance with EMC Directive 89/336/EEC is
necessary (see appendix C), the maximum drive-to-motor cable distance for
which a mains input filter may be used must be also be considered (25 m for
S20-MF1-xxxx filters listed in appendix C.)
All of the limitations described above must be considered for your installation. The
smallest of these numbers will dictate your final limit.
D.2 Drive-to-Motor Wire Type
The type of wire that is recommended to be used between the drive and motor is
dependent on the environment in which it is used. The use of wire with PVC (PolyVinyl
Chloride) insulation is restricted to certain conditions. A common example of this wire
type is THHN. In these conditions where PVC is not recommended, XLPE (Cross
Linked PolyEthylene) is recommended. An example of this wire type is XHHW-2. The
action of pulling wire through 90 ° bends in conduit removes some of the wire’s
insulation. For this reason, extra care should be taken during this process and a wire
with above average insulation thickness should be chosen.
1
When using wire with PVC type insulation, standard 15mil thickness is adequate under normal conditions;
however, when multiple motor’s wires are run in the same conduit for more than 50 ft (15m), and the voltage
is greater than 240V + 10%, 20 mil or greater thickness is recommended.
Condition
Recommended Wire Type(s)
Insulation Type(s)
Example(s)
Dry
PVC
1
XLPE
THHN
XHHW-2
Wet
XLPE
XHHW-2
