Rockwell Automation RELIANCE ELECTRIC SP500 - 3.2.4 Recommended Motor Lead Lengths

3.2.3. Recommended Control and Signal Wire Sizes
Table 3.6 shows the recommended wire sizes to connect I/O signals to the terminal
strip on the Regulator board. The minimum wire insulation rating is 6(00V. Operator
controls can be up to 303 meters (1000 feet) from the SP500 drive. All signal wires
should be twisted-pair.
Table 3.6 — Recommended Control and Signal Wire Sizes and Tightening Torque
Minimum Maximum Maximum
Drives Terminals Wire Size Wire Size Tightening Torque
All 1-16 20 AWG, 14 AWG, 0.5 Newton-meters
0.5 (mm?) 2 (mm?) (4.5 in-lb)
3.2.4 Recommended Motor Lead Lengths
The following motor lead lengths are recommended to reduce line disturbances and
noise. See figure 3.5.
* For applications using one motor, motor lead length should not exceed 76 meters
(250 feet).
* For applications with multiple motors, total motor lead length should not exceed 76
meters (250 feet).
When total lead length exceeds 76 meters (250 feet), nuisance trips can occur,
caused by capacitive current flow to ground. Note that these capacitively-coupled
currents should be taken into consideration when working in areas where drives are
running. If the motor lead length must exceed these limits, the addition of output line
reactors or other steps must be taken to correct the problem. See tables 3.7 and 3.8.
Note that the motor lead lengths shown in table 3.7 are maximum distances. Your
application may be restricted to a shorter motor lead length due to:
* the type of wire
* the placement of the wire (for example, in conduit or a cable tray)
* the type of line reactor
* the type of motor
SP500 Drive SP500 Drive SP500 Drive SP500 Drive
15m (50’)
38m (125’) 38m (125') 61m (200°) 76m (250’)
(oir) 61m (200’)
8m (25') 8m (25) :
All examples represent 76m (250°) of motor lead length.
Figure 3.5 — How to Measure Motor Lead Lengths
SP500 AC Drive Installation and Operation Manual Version 3.1