Hospital Isolated Power Panels 1

[tg103]

Hi, I am new to this forum and hope someone can lead me in the right direction.

I have been a service technician at a local hospital for years providing power quality monitoring, infrared inspections, energized and de-energized equipment maintenance, and troubleshooting on many aspects of the hospital systems.

Recently I have been asked to put together a preventitive maintenance program on the Isolated Power Panel boards located in a section of the hospital. The panel boards are Square D 100A 240/120V IPP type with IsoGuard Line Monitors, some older Series A and a few Series D.

I am somewhat familiar with NFPA 99 and NEC 517-160 requirements and was wondering if someone could help me locate recommended PM's and/or testing procedures (preferbly energized) to prove the LIM's operation.

Thanks for any help!

 

[mpparent]

Don't the panels have PM recommendations in hardcopy format that came along with the panels? If not, the manufacturer might have some literature regarding maintenance.

Mike

 

[tg103]

Yes, hard copy is available but unlike all other distribution equipment's NEMA recommended maintenance these panel boards recommend contacting local Square D field services office.

They do not want to offer their procedures they just want to perform them.

 

[advidana]

Try Electro Test (or other testing companies) they do all types of testing but they will also set up a training program for you. They are not cheap but when it comes to life safety no cost is too high. Talk to these guys then have your boss pay for your traning. Also try to contact other companies that make isolated ground panels, they may help you. Also IEEE std 602 explains thev operation of these panels and LIMs but does not have testing procedures. Good luck-most of the health care information on electrical systems is hard to find.

 

[DanDel]

I have performed Acceptance and Maintenance testing on these panels and associated equipment.
The main concern is adequate grounding and correct initial installation, and regular testing of the alarms.
Check to verify that all wiring is correct. I have found some of these units wired incorrectly with the main breaker wired in the wrong place in the circuit. Check the manufacturer's diagram, but I believe the Main C/B is supposed to be connected on the primary of the transformer instead of just ahead of the feeder C/Bs.
Once the grounds to each protected circuit are tested, usually by a ground test set from each device ground lug to the appropriate ground point, a test is made at each device to provide a resistance between each line connection and ground which would cause the set amperage (typically 5mA) to flow. This will cause the alarm to sound.
A plug-in GFI tester can be used for this purpose, but the best method is to use it in conjunction with a Hospital-rated testset (such as a BioTek) so that you can reverse polarity and test both sides of the circuit to ground(there is no real 'hot' wire in this system).
You could also perform a zero-out adjustment of the analog meter, exercise the C/Bs, and check the panel test button for correct operation.
Unfortunately, to perform most of these procedures correctly, you will have to be allowed to de-energize the system at some points.

 

[tg103]

Thanks all for the info...DanDel, those were the procedures I was thinking of performing. I didn't think about reversing the polarity, good idea. I built a test set using a rotary switch with resistors and milliammeter to simulate and monitor ground leakage ranging from 1mA to 9mA.

By using cord and male cap I would allow current to flow from (normally) hot side to ground, you think I should dupicate test from neutral side to ground as well?

I will be allowed to de-energize the system on a room by room vacancy basis.

Thanks!

 

[DanDel]

You need to perform the test on both sides because this system is isolated from ground and there is no real 'hot' wire. Both of the conductors have the same potential to ground.

 

[WoodrowJWeen]

Does anyone know of an official "certification" procedure for these panels?