Heat Loss for Electrical Equipment

[sc57ford]

Looking for published data or "standard" (such as ANSI, ASHRAE, or other reliable source) in tabular form, if possible, of heat loss in electrical equipment, such as starters, busduct, low and medium voltage breakers, power circut breakers, etc. I presently have some unpublished data, and do not know where it came from. I am using this data in a spreadsheet to calculate the total heat gain into electric rooms, and provide this information to the HVAC designers for sizing the unit for these rooms. Any helpful web links would be appreciated. And Thanks in advance.

 

[peebee]

The heat loss from panelboards, switchboards, etc., is so low that your HVAC guys should be able neglect it; it should be much much lower than any other heat loads in the room.

If you come up with anything to the contrary, please let me know.

Transformers and other energy conversion equipment are obviously a different story. Transformers are typically 97 to 99% efficient, the remaining 1 to 3% is rejected as heat.

 

[jbartos]

Suggestion: The larger transformers are manufactured with efficiencies better then 99.4% nowadays.

 

[jbartos]

Suggestion: Visit

http://www.esmagazine.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2503,84723,00.html

http://www.uoregon.edu/~wely/arch591/conclusion.html

http://www.isbn.nu/toc/0471156965

(for Mechanical and Electrical Equipment for Buildings tables)

http://www.hvac-software.com/main.asp

etc. for more info

 

[sc57ford]

Thanks to both you gentlemen for your help. The esmagazine article comes the closest to answering my question, so far. It does appear that there are no such published data or any tabulated information. So I guess its time to begin the chase to the manufacturers for information and do my own tabulation. All this will be time consuming.Thanks again.

 

[peebee]

Keep in mind that one of the largest sources of heat in the equipment you mention will be at the cable lug landing pads.

 

[dpc]

See thread 238-29865. I posted some info from various manufacturers.

 

[jbartos]

Suggestion: This information is also available from HVAC discipline since they use these equipment heat releases for a design of HVAC systems. It may be a good idea to post it in that discipline in this Forum.
The following Reference is sometimes used by power system engineers:
Herbert N. Hickok "Electrical Energy Losses in Power Systems," IEEE Transactions on Industry Applications, Vol. IA-14, No. 5, pp 373-387, September/October 1978

 

[Bung]

Note that fuses can are a source of heat - amount depending on rating and loading. I don't know if the couple of hundred watts from the fuses in an indoor sub is significant for HVAC - if it is part of the general building air-con I would guess not. Certainly it pales into insignificance against the transformer losses.

Bung
Life is non-linear...