The current line of iMacs are not PPC. A moderator has been asked to move this thread to the Intel forum.
Current iMac specs are on http://www.apple.com/imac/specs.html older ones are here:
If you add the year to the search you can find more specifically the details for the model you are buying.
I am doing a calculation of loads for an office space - we will install 36 iMacs. Can you tell me how many amps does an IMac take? Thank you
Here is the document you need (2009 to 2011 models only) for btu and power consumption.
Power consumption is stated in watts, remember to convert to amps.