Industrial Control Panel Main Disconnects

[el35]

Industrial Disconnects

The JIC (Joint Industrial Council) used to have a standard stating that the door on a disconnect had to be latched, if door was in closed position, before turning on disconnect. Where can I find information on when and why this is no longer a requirement? In most panels this meant a 3 point latch, but it depended on size of door to panel.

 

[dbaird]

NFPA 79 Electrical Standard for Industrial Machinery covers this. Check:

http://s42.yousendit.com/d.aspx?id=07VO3MNADKIN32GFO2SVV22PI2

David Baird
mrbaird@hotmail.com
Sr Controls Designer
EET degree.
Journeyman Electrician.

 

[el35]

I cannot find anything in NFPA 79 that covers my question. It was a standard of some sort through at least the late 80's. I am trying to find out when it was dropped and why. If safety regulations are written for electricians working on an open panel, it would seem to me that the door should be required to be latched before being turned on my other people.

 

[jraef]

JIC is no more, and never was an official regulatory agency. Most of it's standards have been adapted by other oficial sources such as OSHA and the NFPA 79.

Check out thread242-1929

Having said that, I too could not find his particular issue mentioned. It may be one that slipped through the cracks, maybe intentionally, because I know for a fact that it caused may European manufacturers nothing but headaches since they had no equivalent standards and did not have products that would work.

What the JIC required was bi-directional interlocking: you could not open the door without turning off the disconnect, but also you could not turn on the disconnect without latching the door first.. IEC safety disconnect products are based on the combined function, where as soon as you energize the disconnect, the disconnect mechanism interlocks with the door so that you cannot open it. The subtle difference is that the door is not necessarily "latched" in that you can have the door partially ajar even with the disconnect On. That would not have satisfied the old JIC standard.

I don't know what went on in the back rooms, but I suspect that under pressure from international manufacturers (who now own most of the old NEMA manufacturers), that subtle difference was allowed to quietly drop off the radar.

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[jraef]

Just FYI, that old JIC standard was EGP-1-1967, for what it's worth.

This guy said he had a copy of them back in 2003,but who knows if he still does. Might be worth asking.

http://www.control.com/1026164855/index_html