Heat Losses in Electrical Equipment for Sizing HVAC Units

[txj9428]

I am looking for a table of estimated heat rejection values for various electrical equipment. I have an old document that is titled the same as the subject and was issued as a GE Application Tips Letter No. 4. Rev. 1.

I have small VFD's, 480V MCC, 7200V Switchgear and Bus Duct and MV Soft Starters.

Thanks in advance.

 

[alehman]

Manufacturers should have this information available. Cutler-Hammer and GE publish typical heat loss data for switchgear and transformers. If I recall, GE's MCC application guides include typical heat loss values. If not stated in the literature, sometimes heat loss can be deduced from published efficiency values for items such as drives and transformers. Heat loss from busway would be fairly easy to calculate if you know the resistance.

Keep in mind that in nearly all cases, heat production is related to the operating load.

 

[burnt2x]

Please try other fora, HVAC perhaps.

I also have an old table, maybe just like what you have! It has heat rejection values but does not specify heat rejection of equipment like VFD's, switchgears, etc.

If you have efficiency data from manufacturers, you could calculate the heat lost in terms of the total power transfered by the equipment multiplied by (1-eff).
The conversion of 1 watt to heat is 3.415179 BTU/HR

Hope this helps.

 

[7anoter4]

Hi txj9428
It is only from my experience but it was quite ok.See attachment
Best Regards

 

[txj9428]

Thanks for you the file. When I get a chance, I will pdf the file that I have and upload it here.