Multiple VFD's with Varying frame sizes in same enclosure?

Is it OK to have multiple Frame size VFD's inside the same enclosure that will be dedicated to VFD's only or is there any code/regulations against doing so?


Frame sizes will 4 A's and one D.


Thanks

Frame size means nothing to anyone but the person designing the box.

No problem. It's done all the time.

jraef, rupej,


Thank you both. I have never seen a VFD enclosure panel with more than one VFD inside of it(other than in pictures), at customer sites to date. On each one I have seen, there was a lot of empty space left inside of them. Sort of like parking a Yugo inside a double car garage if you will. So I read up on some NEMA specs, but didn't find anything that dictated the enclosure footprint nor did it state that only one VFD can reside inside of one. Therefore I asked the question to be sure.

Now the next question.....To cool or not to cool?

If VFD manufacturers installation guidelines are followed and proper spacing is allowed between the VFD's per their recommendations, do I still need to install a enclosure cooling fan?. The VFD Panel will be inside climate controlled plants where ambient temps will never exceed 25C (77 F). Will the VFD enclosures still need cooling? VFD's will only run the motors involved in the process for around 2 hours starlight at the most. Then, they will have a 2 hour idle time before the next cycle is started. This will continue on 24/7 basis.


Thanks again.

Yes the panel will most likely need cooling. Unless it is large enough to remove the heat generated by convection.

Decent rule of thumb is 6% of the rated duty of the VSD will be it's heat output. (100kW VSD would generate 6kW of heating).

Rittal have some free software that will calculate what you require called rittal therm.