Does NEC apply for equipment internal wiring

[jnpcook]

I work for a manufacturer of induction heating power supplies and associated equipment. I have heard that the NEC applies to the building wiring such as from the power supply to the main disconnect switch on our induction heating power supply but that the internal wiring, etc is covered in NFPA79 Electrical Standard for Industrial Machinery. (I am aware of NEC article 665 that does briefly cover induction heating equipment).

My question is this, does the power supply that we manufacture here need to be approved by a UL lab? We have built the same type of equipment for years and have never sent it into a UL lab for listing and have never had a problem concerning this. The plants where our equipment have gone have always installed the equipment without a problem. We currently have a plant where they are insisting that the induction power supply must be UL approved. Any help or referral to NEC or NFPA79 articles would be appreciated.

John

 

[tom baker]

Re: Does NEC apply for equipment internal wiring

In Washington state your product would be required to be listed. Its up the AHJ to determine how to accept the product, most use listing and labeling as a basis for product acceptance. See 90.4 and 90.7.
And the correct terminology is listed, not approved. By the way, OSHA requires listing, but it can be by a NRTL, of which UL is one of many.

 

[jnpcook]

Re: Does NEC apply for equipment internal wiring

Does this still apply if the machine is a custom built machine? We are in the State of Michigan.

IN MIOSHA article 1910.308(d)(iii) it states: "With respect to custom-made equipment or related installations which are designed, fabricated for, and intended for use by, a particular customer, if it is determined to be safe for its intended use by its manufacturer on the basis of test data which the employer keeps and makes available for inspection to the Director of the department of labor and his duly authorized representatives."

This paragraph is in the section discussing approval, acceptable, and listed equipment.
It basically sounds like a self approval type of inspection.

Is this correct?

John

 

[tom baker]

Re: Does NEC apply for equipment internal wiring

Don't know about Michigan, even though I am from Cereal City USA (Battle Creek Michigan), you should check with your AHJ. I do know if you tried to install one of your products in Washington State it would be a violation, the correction would be for field evaluation, by UL at about $2,000.
There probably is a UL standard for your product.

[ May 20, 2004, 11:27 PM: Message edited by: tom baker ]

 

[richwaskowitz]

Re: Does NEC apply for equipment internal wiring

I work for a controls systems integrator based in Michigan (Detroit area) and our panels get UL stickers before they go out thhe door. If you would like some direction on how you can do this too, private-post me and I will see what I can do to help.

Rich W.

 

[rbalex]

Re: Does NEC apply for equipment internal wiring

A list of standards FedOSHA considers subject to NRTL certification may be found at:

http://www.osha.gov/dts/otpca/nrtl/allstds.html

Your control cabinets will almost certainly require some form of certification.

Your MIOSHA is a verbatim quote from FedOSHA 29CFR1919.399 (definition of "Acceptable")

Both Michigan and Washington State OHSA are "certified" state programs by FedOSHA but both use standards sufficiently different that neither have received "final approval" - at least by the current FedOSHA website.

[ May 21, 2004, 11:36 AM: Message edited by: rbalex ]