nec medical panel

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charliemandeville

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when designing a medical prodicts for class 1 division 2 environments i would like to use solid state relays with 22K isc ratings instead of circuit breakers for controlling small microprocessor and fractional hp motor loads loads. panel would contain one main cb for overcurrent conductor and short circuit protection. Need opinions and suppliers of nec approved devices. Thanks
 
Charlie, where are these hospitals located that are still using flammable anesthesia?

Check into Square D medical products, Post Glover Halsey, and Isotrol for a few manufacturers of Isolated Power Systems, there are others too.

Roger
 
charliemandeville said:
potential application within c-5 aircraft envelope.
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The NEC doesn't apply inside the airframe. This doesn't mean your concerns aren't valid, of course; simply that they are not addressed by the NEC.

From your response to Roger, I assume that you are using nonflammable anesthetizing agents. If it is true, I am curious about the basis for classifying the interior of the airframe since most jet fuels are Class II combustible liquids.

In any case, assuming Class I, Division 2 is the correct classification, the only concern I would have is that the solid-state relays have a compatible ?T-rating? with the location. I would also suggest that you have the whole assembly receive NRTL certification for Class, Division, Group and ?T-rating?.
 
T rated Solid state relays?

T rated Solid state relays?

Mr. alexander. thanks for your information and response to my question on the med panel application. Please clarify the "T" rating of the devices. I respect that the NEC does not specifically cover the devices within the airframe. The environment we are designing for is for JP gas or aviation fuel. Also when you recommend an NRTL certification does this have to be the complete assembly including the enclosure or can the devices be individually certified. Thanks in advance for your expert opinion and continued support of the Mike Holt page which I consider the best industry resource.;)
 
?T-rating? is a general reference to the marking requirements for equipment in hazardous locations in Section 500.8(B), specifically 500.8(B)(4). I tend to use the term ?T-rating? because there are actually several means to comply. You probably should review and understand all of Section 500.8. Since solid-state devices generate heat whether they are arc-making or not they need to comply with 500.8(B)(4).

You may want to review the MSDS (material safety data sheet) for the fuels involved. It is very possible no hazardous location classification is necessary at all.

The NRTL would be in a better position to tell you the required scope of their investigation.
 
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