height of disconnects

[mfred]

I am installing a 400amp service in an electrical room in a plaza and am running out of space to mount equipment. The existing MDP will feed a 400 Fused disconnect which will then feed a 400amp meter can and from there I have to feed 2 200 amp disconnects controlling 2 seperate 200 amp panels in one of the plaza spaces. I have room to install the 400amp disconnect and meter can at standard height (approx 6ft. high) and wanted to mount the 2 200 amp disconnects above them which will be approx 8 feet high when complete. I was wondering if I can install the 2 disconnects higher because they are feeders as long as the main 400amp disconnect is at normal height. thanks

 

[charlie]

Re: height of disconnects

You will have a problem with section 404.8(A) since the circuit breakers are not just the overcurrent devices. They are also the switches for the circuits they are feeding. If I were the inspector, I would nail you on that provision.

 

[BAHTAH]

Re: height of disconnects

mfred, just a suggestion without knowing the obsticles you are facing. Would you pick up enough room if you used an enclosed breaker for the 400amp main instead of the fusible switch. A 400amp fusible switch is typically much larger then an enclosed breaker. Also is the metering utility or customer? In my area we use E-mon meters for tenant space customer metering as they require much less space.

 

[mfred]

Re: height of disconnects

I guess now I am just curious if there is a code restriction for mounting feeder disconnects at that height?

 

[iwire]

Re: height of disconnects

It is all in the article Charlie posted.

404.8 Accessibility and Grouping.
(A) Location. All switches and circuit breakers used as switches shall be located so that they may be operated from a readily accessible place. They shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform.

Exception No. 1: On busway installations, fused switches and circuit breakers shall be permitted to be located at the same level as the busway. Suitable means shall be provided to operate the handle of the device from the floor.

Exception No. 2: Switches and circuit breakers installed adjacent to motors, appliances, or other equipment that they supply shall be permitted to be located higher than specified in the foregoing and to be accessible by portable means.

Exception No. 3: Hookstick operable isolating switches shall be permitted at greater heights.

IMO your best bet is to talk to the inspector about your space restrictions and see if the both of you can reach a decision.

Just a question is there any reason for the 400 amp fused switch?

How about using the tap rules to feed the meter socket directly.

Many times a meter can is feed straight off of the utility with no OCP on the line side.

The two 200 amp disconnects will prevent an overload on the 400 amp meter.

 

[mthead]

Re: height of disconnects

does anyone have a picture of what would qualify as a busway installation as mentioned above?
I've read about them ,answered questions about them on all three exams and yet I've never come accross that term as applied to a situation when I was working or now inspecting.
I appreciate it.

 

[iwire]

Re: height of disconnects

Here is the best picture I could find, the two disconnects on this busduct (busway) are under 6'-7" but if we where to add a couple more large switches onto it we would end up above 6'-7"

Also if this was run horizontal along the ceiling any of the switches on it would be above 6'-7".

Exception 1 allows this.

 

[mthead]

Re: height of disconnects

Thanks for the picture.Now that I see it I have seen it before but it was referred to by a different name-