517 Requires a second circuit to an OR, either a second transfer switch or normal power.
We put in isolated power for the main feed to each OR(critical branch).
Do you think the second feed needs to be isolated power as well.
This has come up with ACHA in florida.
every other state we work in has allowed us to just use 2 GFI receptacles on normal power for the second circuit.

PS this is not a Wet location. We just put in the Isolated power for extra protection.

I don't have any experience with OR's so I can't help you there. But I will say that it sounds like an issue for the engineers.

GJ

Badgers, Isolated Power is not required by the NEC or NFPA 99, it is an option in both cases, as you indicated.

I know North Carolina, and I think Florida, do require Isolation power sources in their proceedure rooms.

Other States or locals may option for GFCI's for their 6ma fault trip levels. (The same as "standard" isolation thresh holds)


If you think about it, why would you introduce "non isolated power" into a room that is already served by an isolated source.

It would definately defeat the purpose.

So, if you have installed a critical isolation source into the room, I would want the normal, or "second" critical source to also be isolation power.


Roger



[This message has been edited by Roger (edited 05-10-2003).]

"If you think about it, why would you introduce "non isolated power" into a room that is already served by an isolated source."
the second source of power in the room is to satisfy the code requirement.
These receptacles are not really used. The only time they would be used is when, the critical branch fails. If the CB fails and normal power is still there, then the GFI's would be used.
The only time this would be a problem if at the same time the CB is gone, an item has faulty insulation.
These panels are 7 grand.
to answer your question.
"why"
I have to tell the owner that they need to spend another 7 grand when the first one wasn't really required. And the only time these other receptacles would be used is.
CB fails but there is still normal power.
And the only time it will be a problem is if a faulty piece of equipment is used during the outage.

"Other States or locals may option for GFCI's for their 6ma fault trip levels. (The same as "standard" isolation thresh holds)"
I am not sure what this means but our isolation panel LIMs alarm at 2ma with a second alarm at 5ma +/- 50µa
this doesn't mean that current is flowing it means it is possible.

I am glad you phrased it the way you did. The inspector used the same logic.
"if you have one isolation panel then you have to have a second." I just can't find a real reason or code reference.
(yes the grounds are bonded between the panels)

thank you for your time and have a good day

Badgers, all due respect, there may be another problem with your installation.


Whose LIM's can do this?

Read 517.160 (6)(b) "the line monitor shall not alarm for a fault hazzard of less than 3.7 ma"

2ma is an old "flameable anesthetizing location area" alarm level and I think a Canadian standard.

Now as far as $7,000 being a question, this will be paid for in one proceedure

I agree the "normal source" would be for emergency only, but, if we were to use two critical sources how would you distinguish between them?

Now, if we are using an isolated system for it's very nature, to provide non grounded power to the patient, then for some reason connect this patient to a grounded system, even if GFCI protected, what would be the reason for spending $7,000 for the first
panel?

Roger