Isolation panels

[kfenn]

I'm planning on using Square D's isolation panel for a locate hospital OR.. Has anyone ever heard or used the Duplex Isolation Panel. Is there any other options that you would suggest me using for the panel....

I have never done an OR before. I not to familiar with the isolation panels. Does anyone have any good website that might help explain the theory behind Isolation.

Kfenn

 

[roger]

Re: Isolation panels

I have used these panels and like them. They are great if you are going to locate both Normal and Critical branches in the same location of the room. (desired anyways)

Here is a good article on Isolated Power Systems as to why.

Roger

 

[kfenn]

Re: Isolation panels

Thanks Roger....Very helpful..
The only problem that we have is that we need about 40 Critical circuits per OR room...They want each recept on its on circuit...A little over kill, but they get want they want.....Can I place two of the duplex ISO panel in the same room? Don't I need a common disconnect(main breaker/switch) that will shut it all down.

 

[roger]

Re: Isolation panels

Kfenn, individual circuits? Man!!!

I would (I'm not an engineer or designer though) install the one duplex panel 16 circuits per side and one single critical branch panel.

Be sure the architect specs the support for these panels in the builders scope, the panels will weigh well over one hundred pounds.


Roger

 

[kfenn]

Re: Isolation panels

Again Roger thanks for your input.

 

[stars13bars2]

Re: Isolation panels

kfenn

These panels and their transformer counterparts are used as roger has noted to isolate and meter minute ammounts of leakage current. Yoy may want to take a look at 517.160(A)(6) fine print notes. Note # 2 was enforced upon me once requiring the removal of #12 thhn and replacing with xhhw. It seemed easier at the time to pull out the thhn, special order the xhhw replacement than to fight the AHJ. You may help all concerned if you just spec xhhw in the plans.

stars13bars2

 

[steve66]

Re: Isolation panels

Can I offer a little free advice? You said they wanted 40 critical branch circuits, but you didn't say anything about normal circuits. An OR should have both normal and critical circuits. Sometimes the doctors and nurses simply want everything backed up by the generator. What they fail to realize though, is that if a transfer switch went bad, or a main breaker tripped, that could leave the entire OR dead. So, the bare minimum should either be critical and normal circuits, or two critical branches each fed from separate transfer switches. This should apply to lights as well as receptacles.

We usually install a dual head battery powered light in OR's also. If the power goes off, it may take the generator 10 sec. to start. That may not sound like long, but when you have a crowded OR with everyone standing around holding sharp instruments, 10 sec. is a long time to be in the total darkness.

Steve

 

[don_resqcapt19]

Re: Isolation panels

stars,

Note # 2 was enforced upon me once requiring the removal of #12 thhn and replacing with xhhw.

The requirement to use XHHW conductors and limiting the types of wire pulling lubricant is often in the installation instructions for the product.

 

[roger]

Re: Isolation panels

Steve, you are correct in that the room must be served by both critical and normal power sources or as you said two transfer switches.

This is the only reason (besides quantity of circuits and receptacles) that I could see a need for the "duplex Panel". (One side Normal and One side critical)

Square D Duplex Isolation Power Panel
The duplex hospital isolation panel is a single enclosure containing two complete 120 V secondary hospital isolation systems. A divider in the unit's backbox separates the systems from top to bottom and front to back.

Each system has its own set of equipment:


Stars, as Don says, manufacturers include the XHHW and lubricant information in their instructions.

Here is an excerpt from the link (an article from SQ D) I posted above.

Use cable with the best insulation possible. The insulation on the cable should have a dielectric constant of 3.5 or less and, in this regard, all XHHW wire is not created equal. Square D recommends Rome Cable brand, catalog number VW-1 XHHW-2 Spec 2110 because it seems to consistently give the best results. The particular wire you are using may be listed as having a dielectric constant of less than 3.5, but wire manufacturers generally do not list an absolute dielectric constant. So you don?t know if the wire?s dielectric constant is 3.49 or 2.49. Wire insulation types THHN, THHW, THW, THWN and TW are not suitable for use on isolated power systems.

Do not use wire pulling lubricant of any kind on the branch circuits. Wire pulling lubricants tend to change the dielectric of the insulation. If in doubt about the ability to pull-in the conductors, use a larger conduit. The insulation on XHHW wire is thicker than THHN and not as slippery. So plan ahead and ask you distributor for some wire samples.


This is true of other manufacturers too.

Roger

[ January 14, 2004, 10:53 AM: Message edited by: roger ]

 

[pierre]

Re: Isolation panels

Roger
Wow, that is very informative and easy to follow. Thanks for the good info!

Pierre

 

[lady sparks lover]

Re: Isolation panels

Can I sneak in here??

 

[roger]

Re: Isolation panels

Patricia, this is actually bonding that occures in these systems vs grounding.

The upstream source would not have any bearing on the Isolation System except for "Magnetic Coupling"

The bonding would be done the same as any bonding I.E. EGC connections, and this bonding would connect to the service EGC back to the Grounded Conductor.

This would be "isolated" from the ISO system windings, (kind of a strange looking sentence, but is the definition of the system)) and any fault at minute levels to the service EGC will put the LIM into alarm. The LIM will also alarm at capacitve or inductive leakage levels that exceed 5 ma.

Roger