How bad could this get (VFD Overheating)

[rdrast]

I did exactly what you said Tom with the Hoffman calculator before I went to him. I got numbers that suggested I needed like 3 of Hoffmans largest 24v fans with exhausts.

Oh well, you can only lead the horse to water. I know he is concerned about chlorine and to have this system sealed, and only running 2 VFD's at a time (sure they will), you would be looking at like a $3.5k AC unit if I am right.

Much hate for any kind of cabinet air conditioner. They are expensive, costly to run, and fail with incredible frequency.

Use isolated Air to Air heat exchangers, or, if you have a water supply, an air to water exchanger. Hoffman, Rittal, and others all have them.

My preference is for the Air/Water exchangers, BUT if you use a chilled water supply, install a solenoid valve to cycle the supply on and off to prevent condensation.

 

[BobB]

Do not put them in the cabinet. Even if you put in fans idiot customers do not clean the filters and all of a sudden you PLC and other gear is 'crispy' to say the least. Have this problem all the time.
I only use IP66 rated drives and they also have to have low loss filters as they have to run on 30ma RCDs - swimming pools. I will only use 1 brand of drive for this - Zener Electric - made in Oz.
We mount them on a stick near each pump and then only have to run 1-2 metres of that frightfully expensive screened cable.
Good result for all - works - saves money.
Many stupid drives people say 'just cut out the filtration to earth and the RCD will not trip'! Not good enough - then does not comply with noise standards.