Technical FAQs

Ask a Question

Can voltage spikes cause the drives motor cables to overheat and also whats the recommended motor cables types?

Can voltage spikes cause the drives motor wires to overheat and also whats the recommended motor cables to use?

Product Line:
Altivar Drives


Voltage harmonics and transients. 

Electrical phenomena on drive input is completely different than the output. On line cable,voltage harmonics is less than current harmonics
,and on drive output ,voltage harmonics is higher than current harmonics (low distortion of motor current , high distortion of voltage due to drive PWM).
For the output ,impact on copper wire is low (if section is correctly define conforming to current),but it is important to have a good isolation property for cable.
It is advice to used 1kV cable ,but it is also important to have good hi pot feature too (ie 4kV).In fact,PWM of drive generate a high dv/dt signal (about 5kV/µs) ,
with a possible overshoot / overvoltage on motor side due to signal reflection (overvoltage can be higher than 2 times of DC bus voltage) due to motor cable length.
This overvoltage can be seen by to motor terminal ,and by motor cable too.Dv/dt value will generate earth current due to earth/wire capacitance of cable (mainly with shielded cable).For motor cable 
,we recommended some kind of cable like :for shielded cable : "GORSE" (GUOSTV-LS/LH) or "PROFLEX" (EMV2YSL CY) ; for unshielded cable : "GORSE" (H07 RN-F4GXX) or "BELDEN" (2950X).
It should be a good point to see with cable manufacturer to have the best referency of motor cable to operate with drive.
Was this helpful?
What can we do to improve the information ?