X-Ray load demand factor

[kenaslan]

What is the demand factor applied to X-Ray equipment? 65%, 100%, 125%? I have found demand factors from everything from Elevators to kitchen equipment, however I cannot find a demand factor for an X-Ray in order to load the main service.

Thanks
Ken

 

[celtic]

100%

See 660.6(A) & (B)

 

[charlie b]

It's not on any list, so you can't use anything less than 100%. It's not a motor or a continuous load, so you don't need to use anything higher than 100%. I'd go with 100%.

 

[nyerinfl]

660.6. You should look at it for your specific application, as it can vary by number of x-ray machines, and the momentary demand ratings.

Edit: Listen to Charlie, I was looking at feeder rating.

 

[barbeer]

If what you are looking for exists IMHO it would be in 660. I do not believe 220 addresses this.

 

[barbeer]

slow typer!

 

[kenaslan]

Thanks everyone

It is hard to believe that 220 has not given a demand factor to X-ray equipment. My guess is that they have a duty cycle once every few min for only a few seconds. However a demand factor of 100% is still required untill the NEC catches up.

Ken
MEP Test Dummy

 

[steve066]

If its a medical xray, look in article 517. Medical Xray units usually have a long term rating, and a momentary rating.

For the momentary ratings, I think its 50% for the 1st one, 25% for the second one, and 10% for the 3rd and above. (Dont have my book with me, so that may not be exactly right).

Of course, you have to use 100% of every long term rating.

Steve