517.17

[Nick]

Article 517.17 states that where ground fault protection is required at the service disconnecting means (480V systems 1000A or more) one additional level of ground fault protection shall be provided in the next level of feeder disconnecting means down stream towards the load.
Am I correct in the following statements?
#1: All down stream feeder breakers must have the GFP protection. They do not have to be 1000A or more.
#2: This requirement applies to a medical office building that contains radiology areas and basic patient care areas. In other words it is not a ?Hospital? governed by OSHPOD regulations but it does contain examining rooms and light out patient procedures are done.

 

[BAHTAH]

Re: 517.17

Ambulatory care centers are considered Health Care Facilities (517.2). The requirements of Part-II shall apply to patient care areas of all health care facilities (517.10(A)). Unless your facility meets the requirements of 517.10(B)(1)or (2), I would say you are correct in your statements. The additional step of ground-fault protection is not limited to only 1000 amp breakers. If the main is 1000 amps, then the feeder breakers supplying patient care areas should have ground-fault protection with a 6-cycle minimum separation between them and the main (517.7(B)). If the feeder supplies an office only, then it does not require the ground-fault protection.

 

[Nick]

Re: 517.17

Grant,
Thank you. I believe this facility requires the second level of protection. There are a total of 22 secondary breakers in this board ranging from 100A to 1000A that are not called out to have GFP. The building has areas that fall under 517.10(B)(1) but I don?t think that exempts the entire facility.

I guess I need to go be the bad guy again. :roll: