The Electrical Contractor Network

ECN Electrical Forum
Discussion Forums for Electricians, Inspectors and Related Professionals

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured:
   

2017 NEC and Related
2017 NEC
Now Available!

   
Recent Posts
230 or 345 kV transmission lines?
by Vlado
Today at 09:33 AM
breaker meltdown
by crselectric
Today at 12:42 AM
Electrical mast flashing product
by ThomasWinfrey
09/22/16 12:14 AM
What estimating software do you recommend?
by sparky
09/21/16 07:20 PM
"Dry Run" Inspection goes awry
by HotLine1
09/20/16 07:39 PM
New in the Gallery:
12.5A through 0.75mm˛ flex (just out of curiosity)
Shout Box

Top Posters (30 Days)
HotLine1 17
sparky 9
gfretwell 9
sparky66wv 8
Vlado 6
Who's Online
0 registered (), 262 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
Topic Options
Rate This Topic
#185338 - 03/11/09 12:00 PM Service size for Chiropractic Office: X-Ray
Wardey Offline
New Member

Registered: 12/04/04
Posts: 1
Loc: Palm Harbor, FL
Trying to size a service for a chiropactors office and not sure on the demand for an X-Ray machine. The X-Ray Tech say's he needs an 100 Amp 220V circuit. Here's what I have existing:
100 Amp 3 Phase Service w/ 1 Alum Conductors

So do I figure the X-Ray machine at 100% demand?

And my load calcs would be:
12 receptacles @ 180VA = 2160
640sq.ft. @ 3 VA = 1920
Heat @ 10,000 VA
Sign Ckt. @ 1200 VA
X-Ray Machine @ 24,000VA
Total 39,280 VA

39,280VA / 240V = 163.66 Amps / 1.73 = 94.60 Amps

Correct? The 100 Amp service should be suffecient?

Thanks !!!

Top
Work Gear for Electricians and the Trades

Work Gear for Electricians and the Trades
Work Gear for Electricians and the Trades
Arc Flash Clothing, Gloves, KneePads, Tool Belts, Pouches, Tool Carriers, etc. etc....

#185339 - 03/11/09 02:18 PM Re: Service size for Chiropractic Office: X-Ray [Re: Wardey]
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
if your using 240 x 1.73 it must be a high leg delta??
IF ITS A 120/208 Y (most common) it be 208 x 1.73 =359.84
Just checking.

Top
#185341 - 03/11/09 03:15 PM Re: Service size for Chiropractic Office: X-Ray [Re: Yoopersup]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA
Yoop,
Wrong answer.

If 208 volts you DIVIDE it by 1.73
Not MULTIPLY it.

39,280VA / 208V / 1.73 = 109.15 Amps




Top
#185343 - 03/11/09 03:26 PM Re: Service size for Chiropractic Office: X-Ray [Re: electure]
Yoopersup Offline
Member

Registered: 03/04/03
Posts: 826
Loc: Michigan
39280 divide by 359.84 =109.15962
Sure looked like devideding to me?????

1.73 x 208= 359.84
39280 Divided by 359.84


Edited by Yoopersup (03/11/09 03:31 PM)

Top



ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals