VFD Cables

[timm333]

Does the size of “cables” feeding VFD operated motors need to be bigger than across the line motors?
Also, can the regular cables be used for VFD operated motors, or are there some special cables for this purpose?

 

[wareagle]

MFG will usually make recommendations for cable. Check

http://www.belden.com/07markets/07_Industrial/07_Industrial_Products/VFD_Cable.cfm

for additional information.

 

[cjhut]

wareagle is right. The manual for your drive should give you some specs. As far as cables go, same thing. If you are running say a tray cable in cable tray with other wires in the raceway, you may want to use sheilded cable. If it's in conduit by itself you could run Thhn for example. Remember to note the temp ratings of the connections on the drive itself. You may have to derate for that also. From past experience some drive manufacturers want you to increase your conductor size after 50feet.

 

[itsmoked]

Typically there is no difference in wire types. Use the correct size of whatever you can get your hands on to hook up a motor without a VFD.

There is shielded power cable you can get which would be better to use but never once have I been able to get it without such a ginormous hassle, that I go without out it - and have no issue anyway.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[dpc]

The cabling from VFD to motor is a rich source of radiated electrical noise due to RFI. Best approach is to run it in metal conduit and do not run anything else in the conduit with it.

Shielded cable is generally recommended by VFD manufacturers these days. But there are certainly a lot of circuit installed using standard wire and working just fine.

We have used Okonite C-L-X for some of this wiring in the past - it seems to work well also.

David Castor

http://www.cvoes.com