Minimum Distance Between MCC and Wall

Zero, I think. (Else most MCCs I've seen are installed incorrectly.)

The minimum clearance is 1 radian/fortnight x the square root of the inverse if the voltage is 249V/11, or greater.

Otherwise, zero.

These rules do not apply if the walls are red.

What he said...

But seriously, unless it is a "back-to-back" MCC design, they are made to be totally front access and zero clearance.

Maybe we should distinguish between the back clearance (zero) and the front clearance of walls or other obstructions. In the NEC (U.S. National Electrical Code), the required clearance is 3 feet up to a certain voltage, and 4 feet for higher voltages. I forget the dividing line--something like 250 or 300 volts.

My mistake in ASS-U-Me-ing the OP was referring to clearance to the BACK wall, it actually wasn't clear. Good on you all for catching the distinction.

LOL on your signature line cuba pete.

If (s)he is referring to back wall clearance, (s)he needs to choose a new profession.

Unless, of course, it is a double-sided cabinet. There is a lot to assume, isn't there?

With some of the genius designers I've come across it's maximum panel door width minus six inches so it's impossible to fully open the door!

Exactly. One does need to be able to get the door open!

You need to look at your local fire codes. As the clearance is set by those. Here I believe it's 5 feet. That is not just from the walls but any obstruction.

msamad; that link ROCKS!!!! if you back up a little in that directory there is a proverbial a$$load of info on there!!! as for the MCC issue; unless prevented by composition of the wall (rice paper, balsa etc) a front only unit is designed to be mounted against the wall..unless "local jurisdiction" requires otherwise.

Hi msamad,

I agree 100% with duffdr when he writes that the site you gave is MAGIC. Thanks!

A little further back on that same site is a list of very interesting E-Books as well.

Regarding the OP's question I think your answer goes right to the crux of the question by stating 'sufficient working space being required'. Apart from the legal requirements (which often tend to give the minimum requirements) a practical approach which allows easy access should always be employed.

Reading some of the other posters comments I was reminded of times when I would have to actually take the door off in order to get clear access.

Great link! Thanks for the magic.

From a ventilation point of view it is better to have little clearance.

In real no standards as such, but the minimum clearance is whatever you need to open the MCC for maintenance access and to take items in or out of the MCC.

If the MCC is specified as front entry than you can place it right against a wall if you want, generally leave a space for ventilation.

Mr. Vithal,

you can download "Indian Electricity Rules" from "www.india.gov.in" for your reading.

Following are the required clearances around a MCC.

Front: minimum 3ft (from any projected point)

Sides: Less than 200mm or more than 750mm

Rear: It can be flushed to wall if it is single front, otherwise less than 200mm or morethan 3ft.

sitaram.

Dear Sitaram,

Thank u for your reply can you please give me exact link wherin i can get this info

Mr. Vithal,

i gave you the url of Govt. of India where you will get many of acts & rules. Any how, here is the direct link to Indian Electricity Rules-1956.

http://www.india.gov.in/allimpfrms/allrules/484.pdf

sitaram.

Dear Mr. VITHAL,

I believe you are in India. As per I.E.R it is 900 MM min.

DHAYANANDHAN.S

<...minimum clearance required from wall...as per statutory rules...>

Are there such things?