Isolation transformer 517

[hhsting]

I have Operating Room whose receptacles are supplied from two sources: one normal isolation panel and one ATS isolation panel. There are few receptacles that are supplied by normal panel
non-isolated and ATS panel non-isolated but they have GFCI.

Both isolated panels are in operating room and have integral isolation transfromer.

My questions are following:

1. Does the isolation transfromer single.phase 277V to 120V 10kva secondary have to comply per NEC 2014 Article 250.30 grounding and bonding GEC to steel or water pipe?

2. Isolation panels location in the Operating room is per NEC 2014 Article 517 ok?

3. Do the receptacles in operating room have to be on isolated panels or if they have GFCI protection it is okay?

4. Does the normal and essential equipment ground bus bar have to be bonded together of all panelboards isolared and non isolated?

Thanks for your input.

 

[roger]

I have Operating Room whose receptacles are supplied from two sources: one normal isolation panel and one ATS isolation panel. There are few receptacles that are supplied by normal panel
non-isolated and ATS panel non-isolated but they have GFCI.

Both isolated panels are in operating room and have integral isolation transfromer.

My questions are following:

1. Does the isolation transfromer single.phase 277V to 120V 10kva secondary have to comply per NEC 2014 Article 250.30 grounding and bonding GEC to steel or water pipe?

2. Isolation panels location in the Operating room is per NEC 2014 Article 517 ok?

3. Do the receptacles in operating room have to be on isolated panels or if they have GFCI protection it is okay?

4. Does the normal and essential equipment ground bus bar have to be bonded together of all panelboards isolared and non isolated?

Thanks for your input.

1. No
2. Yes 517.160
3. Depends on your states rules but they should not be mixed IMO
4. If they serve the same patient care vicinity yes

Roger

 

[hhsting]

1.What about lights Operating Room from critical, normal or life safety branch?

2. For wet procedure locations Nec 2014 Article 517.20 says (A)(B) so do both options have to be implemented or one of the two (A) or (B) is ok?

 

[roger]

The only Lights that would be on the Isolated Power System or GFCI would be exam or procedure lights that can be touched by someone.

You would not have Life Safety illumination in an OR room

Either (A) or (B) not both.

After all is said and done the new systems will have to be commisioned by someone with the right equipment to test leakage, equipotential, and LIM function. See NFPA 99 chapter 6 (chapter 4 in earlier editions).

Roger​

 

[hhsting]

So I have in Operating Room plan shows 6 - 2x4 light fixtures on ceiling illuminating surgical table , total 12 - downlights on ceiling 3 on each corner, 1 - surgical lights circuit on the surgical table, 22 general purposes receptacles in the room and all of them are as follows:

3 - 2×4 light fixtures are on emergency circuit life safety branch panel ATS, connected ahead of any local switch
6 - downlights are on emerency circuit life safety branch panel ATS, connected ahead of any local switch
3 - 2x4 light fixtures on normal circuit side
6 - downlights on normal circuit side
1 - surgical lights circuit on critical branch side without GFCI and not on isolating power system panel.

2 - receptacles they are for C Arm on critical branch with GFCI not on isolating panels
20 - receptacles on isolating panels combination of normal and critical branch.


Are all the above on correct branch and isolating panels/gfci?

 

[roger]

The designer has a mess. You should read 517.31, 517.32, 517.33, and 517.160 and determine from those section what parts of the design are wrong or applied incorrectly. NFPA 99 needs to be looked at as well.

Roger

 

[hhsting]

Ok thank you. After reading those section, I am guessing 2x4 and downlight on life safety should go to critical branch 517.33(A) task illumination and per nec 2014 Article 517.33(B) critical branch is allowed to be subdivided so rest of 2x4 and downlights on normal branch as they are.

The surgical light is task illumniation but can be touched so it should be on critical branch circuit from isolating panel.

The C Arm receptacles should also be fed from critical branch of isolating panel remove GFCI.

 

[roger]

Ok thank you. After reading those section, I am guessing 2x4 and downlight on life safety should go to critical branch 517.33(A) task illumination and per nec 2014 Article 517.33(B) critical branch is allowed to be subdivided so rest of 2x4 and downlights on normal branch as they are.

The surgical light is task illumniation but can be touched so it should be on critical branch circuit from isolating panel.

The C Arm receptacles should also be fed from critical branch of isolating panel remove GFCI.

I agree with all.

Roger

 

[steve66]

There should also be at least one battery powered light. Even with the critical branch lights.

I think the newer codes state that the battery powered lights should provide enough light to safely terminate a procedure