Disconnect height rules

[cjmpe]

NFPA70 Section 404.8 calls for a maximum height above the floor for a disconnect of 79 inches but provides for an exception (#2):
"Switches and circuit breakers installed adjacent to motors, appliances and other equipment they supply shall be permitted to be located higher than 2.0m (6ft 7 in) and to be accessible by portable means."

Now, I am installing a 2 door disconnect enclosure that has a nominal disconnect height of 68 inches above the floor - this is defined by the flange opening on the enclosure. The problem is that the enclosure is being installed on a houskeeping pad some 15" high. The disconnect will only be used when the system requires a full power down for electrical maintenance

Does anyone out there think that I will have any problems with this installation?

 

[allenwayne]

Re: Disconnect height rules

As far as I know unless if it s a mobile home there is a min.heightMax yes but min listed service gear ,but far as i know there is none .

 

[jim dungar]

Re: Disconnect height rules

One idea is to make the pad big (deep) enough to use as a step to get to the disconnect.

 

[hank1]

Re: Disconnect height rules

This disconnect sounds like a requirement to force maintenance to shut power off to the enclosure entirely to work on the unit. Is there a disco located nearby that services the enclosure?

Hank,

 

[George Stolz]

Re: Disconnect height rules

Originally posted by cjmpe:
The disconnect will only be used when the system requires a full power down for electrical maintenance.

What is "the system"?

Sounds too high. Sounds like Jim's idea isn't a bad one.

 

[mdshunk]

Re: Disconnect height rules

I've only run into that problem once. It was a tall VFD, with a factory supplied disconnect. It ended up about 7' off the floor when it was set on the housekeeping pad. Passed muster anyhow.