Hospital Isolated Grounding Systems

[rvm]

Hello!
From a recent field visit to a Hospital project under renovation, I noticed that all the existing Intensive care units have an Isolated(ground)Power Panel which feeds the outlets on the patient headwall. However, the outlets on the perimeter walls in the ICU room are fed from another power source which has conventional grounding! Is this a code violation? If it is, what is the solution?

Thanks,
RVM

 

[raider1]

Re: Hospital Isolated Grounding Systems

What do you mean by "conventional grounding"?

517.13(A)&(B) (2005 NEC) Require the wiring methods of patient care areas, to be installed in a metal raceway or a cable with a metal sheath listed for grounding. In addition to the metal raceways as EGC you must also install a insulated equipment grounding conductor, which must be connected to the grounding terminal of the receptacle.

Chris

 

[rvm]

Re: Hospital Isolated Grounding Systems

Thanks! I understand the provisions of NEC 517.13(A&B). My question was whether the same ICU could be fed from two sources - one an "isolated power system" and the other from a "grounded power system".

 

[roger]

Re: Hospital Isolated Grounding Systems

I don't think it's a good design, the staff (including all new staff every time a new person is hired) would have to be trained to utilize only the headwall receptacles for equipment serving the patient.

To big of a chance for human error.

BTW, as you mention in your last post, the Isolated System is "Ungrounded", the green conductor attached to receptacles and equipment served by the Iso System is more correctly an Eqipotential bonding conductor, and will not open an OCPD in a leg to ground fault.

Roger

[ January 10, 2006, 11:26 AM: Message edited by: roger ]

 

[rvm]

Re: Hospital Isolated Grounding Systems

Thanks Roger! It's an existing hospital and I am not sure how this situation went unnoticed! However, I am unable to find anywhere in the code books that this is a violation. Can someone help?

 

[jim dungar]

Re: Hospital Isolated Grounding Systems

Actually it is not that hard to train professional people. They know they can plug patient care equipment only into the headwall. It is also easy to see if any "improper" equipment has been plugged in.

The wall receptacles can only be used for non-pateint equipment which reduces the need to run extension cords "out the door and down the hall".

 

[roger]

Re: Hospital Isolated Grounding Systems

Jim,

Actually it is not that hard to train professional people.

you obviously don't work in hospitals much. (that was not a joke)

The real question is, is/are the Isolation Power System(s) even needed in this area.

The original reason for the Isolation Systems was for use in flammable anesthesia areas which are non existent now days except for possibly some third world countries.

Their big use now is in areas classified as wet locations where GFCI's tripping can not be tolerated, mainly O.R.'s.

Roger

 

[jim dungar]

Re: Hospital Isolated Grounding Systems

Up through the mid 80's isolated ground systems were still very popular. Changes in the NEC at time reduced the need for them.