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Disconnect physical height?

Disconnect physical height?

Disconnect physical height?

I have a motor with a fused disconnect. The disconnect is mounted within several feet of the motor. It is in a room that has five other motors. We have disconnects for each motor. The room houses a industrial water filter pool and these are the circulating pump motors. What is the NEC reference for height off the ground for the disconnects? I was told it is 18". I would like to verify this.

RE: Disconnect physical height?

It is definitely NOT 18 inches AFF (above finsihed floor).

In NEC, there are requirements and then there are exceptions. There is a requirement for maximum mounitng height of 78 inches for controls/breakers/disconnects etc. I beleive the height is measured to the center of the operating handle from the floor. (I would tend to measure to the top of the unit, to play safe). You can mount a disconncet higher, if you equip it with a pull chain/rod such that the chain handle is within 78 inches AFF.

The most common practice is to install the disconnects between 54 and 78 inches AFF.

By the way the 18 inches is recommended hight (measured to the top) for mountnig convenience receptacles. ADA (in the USA) requiers mounting of receptacles between 16 and 48 inches, among many other things.

The motor disconncets have nothing to do with ADA.

RE: Disconnect physical height?

It is common to mount equipment on a 4" slab to prevent the equipment from getting wet. but no rule that i know of for +18" . again ada requires about 18" for oulets.

RE: Disconnect physical height?

I did not read the question correctly. 54" to 78" is common for mounting disconnect switches. ada does has a mounting height for toggle switches but that is not the question.

RE: Disconnect physical height?

Thank you for all your responses, however I was looking for the Article in the NEC that pertains to this requirement. I need to be able to refute the installation and justify having them changed.

RE: Disconnect physical height?

you can also reject an installation based on 'unporfessinoal' installation. Stupidity is not covered by NEC.

Get the owner on your side (which he/she should be) and read an riot act to the contractor.

18 inches is not a convenient for operation of a disconncet.

By the what size disconncet are we talking about?

RE: Disconnect physical height?

These disconnects were installed for local disconnect means. They are for small 2hp - 5 hp motors. They will only be used for maintenance. Previously the disconnect means was out of sight from the motors. Fed from another room off a busway. The was an internal installation. This is new guy on block versus 30 years of "experienced maintenance" doing things the way they always have. So that is why I am looking for paper clarification. I do not have control only suggestive input. Thanks,

RE: Disconnect physical height?

See NEC 404.8.  Maximum height is 2 meters, 6 feet 7 inches to the center of the grip of the operating in its highest position.  The basic requirement is that the switch be "readily accessible" as defined in Article 100.  There is no minimum height.  18" would be acceptable per NEC, even if not by common sense.  

But there are some exceptions that allow motor disconnects to be placed higher than 2 meters, if they are installed adjacent to the motor.  You often see this on HVAC fans installed high up on walls.  

RE: Disconnect physical height?

I think these old guys are playing sucker ball with you. Just install thing the right way and let these old guys just fad away.

RE: Disconnect physical height?

Thank you for the reference. Another question since the ADA was brought up. Is there a guideline for when ADA applies in an industrial environment? Is this common sense? An example is the pool area my motors are in, is not readily accessible, therefore why would ADA apply?

RE: Disconnect physical height?

Get a copy of the ADA and read it. It is start foward and easy to understand by most people except maybe clients and your boss. The document explains the thing you are asking. You can usually find it in the Public library. Handy caped people go everywhere so it usually applies to most places.

RE: Disconnect physical height?

I think normally in an industrial facility, the ADA has come to be applied to those areas of the facility that would be accessible to someone in a wheelchair.  This is often limited to ground floor areas and areas accessible by elevators.

I'm not sure that even this is actually required.  The ADA was mainly intended to apply to facilities accessible to the public.   

As much as it pains me to say this, you might have to ask an architect.  

RE: Disconnect physical height?

ADA is only applicable for "public spaces".  It does not apply to electrical rooms, equipment rooms, roofs, etc.  Don't worry about ADA in your case...it doesn't apply.


RE: Disconnect physical height?

ADA extends beyond public areas. You may be faced with a worker asking for "accommodation."  "Reasonable" requests must be met. It's a case by case basis, though. I don't think I would try to plan in advance for every foreseeable disability that could be accommodated.

RE: Disconnect physical height?

This is taken from the US ADA website:

Q. Must every feature of a new facility be accessible?

A. No, only a specified number of elements such as parking spaces and drinking fountains must be made accessible in order for a facility to be "readily accessible." Certain nonoccupiable spaces such as elevator pits, elevator penthouses, and piping or equipment catwalks need not be accessible.

To me...this implies that non-public spaces need not be ADA accessible, only the public ones.


RE: Disconnect physical height?

I'm sure the public accessibility part is as you say. I was disputing your assertion that the (whole) ADA applies only to public areas. Much of it applies to employment. Search on some of the buzzwords in quotes above along with "bona fide occupational requirement."

RE: Disconnect physical height?

ADA requirements applies to Owners, (not employers) is only for public spaces..in a building.

Employement related issues are covered under equal opportunity guidelines and to accomodate a handiapped employee, the employer has to make reasonable attempt to provide facitilies which may follow guidlines of ADA (and more).

But that does not apply to electrical rooms...or other non public spaces..

RE: Disconnect physical height?

or in other words, if you do not have a physically challaged employee, say challaged with eye sight, the you do not have a braille keyboard and computer...

but you do need to install light swithes at 48" AFF max, etc...
but not a disconnect in a mechanical room.

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