MCC Question

[starbright28]

MCC - motor Control Centers.

Is a cement slab required to be installed underneath a MCC or is this just good practice.

My old job place specified this on the drawings, but I can't seem to find a code articel to state you have to do this.

in my current job I have a project that is requiring 1 MCC in a penthouse. I am just curious to know if there should be concrete around and underneath this MCC. the concrete would extend 2" out all the way around the MCC.

Thanks!

 

[jim dungar]

What you are describing is often called a housekeeping pad. This is a design issue, not an NEC one.

 

[LawnGuyLandSparky]

These curbs also help keep small leaks and spills away from the gear. When they're not specified, we always set mccs and switchgear on unistrut.

 

[John Valdes]

Amanda, If you would have taken your masters first. You probably would have a license already........LOL
Good luck on the next test.....John

 

[don_resqcapt19]

Amanda,

the concrete would extend 2" out all the way around the MCC.

While a common practice, that is a violation of 110.26(a)(3). Note, I do not think that the concrete pad is "other associated equipment". The only other issue is making sure that the pad does not place the top operating handles above 6'6".
Don

 

[celtic]

Amanda,

While a common practice, that is a violation of 110.26(a)(3). Note, I do not think that the concrete pad is "other associated equipment".

(3) Height of Working Space
The work space shall be clear and extend from the grade, floor, or platform to the height required by 110.26(E). Within the height requirements of this section, other equipment that is associated with the electrical installation and is located above or below the electrical equipment shall be permitted to extend not more than 150 mm (6 in.) beyond the front of the electrical equipment.

I don't see the violation in the housekeeping pad extending 2" beyond the MCC.

 

[iwire]

Celtic I don't see it as a big deal but I do agree with Don.

IMO the platform they are taking about is a platform to work from.

So to make the housekeeping pad 'legal' it would have to stop flush with the MCC or extend out the required working space.

Of course extending it would be IMO creating a spot which people will trip on or fall from.

 

[bmac71]

(3) Height of Working Space
The work space shall be clear and extend from the grade, floor, or platform to the height required by 110.26(E). Within the height requirements of this section, other equipment that is associated with the electrical installation and is located above or below the electrical equipment shall be permitted to extend not more than 150 mm (6 in.) beyond the front of the electrical equipment.

If I understand this correct, as Celtic stated, this would not be a violation to have a 2" pad extending from the MCC. As stated within the height requirements..........extend Not More Than 6". Am I not understanding this, where is the violation with a 2" housekeeping pad.

 

[celtic]

(3) Height of Working Space
The work space shall be clear and extend from the grade, floor, or platform to the height required by 110.26(E). Within the height requirements of this section, other equipment that is associated with the electrical installation and is located above or below the electrical equipment shall be permitted to extend not more than 150 mm (6 in.) beyond the front of the electrical equipment.

Is a pad "grade, floor or platform" or is it "other equipment"?

IMHO, this is a tripping hazard has been created as iwire noted...a violation for sure, but is it a 110.26(A)(3) violation?

I don't see an issue here with the pad.

 

[Rockyd]

Did You do that Celtic?

I'd call it a nice job.

 

[celtic]

Did You do that Celtic?

I'd call it a nice job.

The only job I did here was searching google.

I'll take some pics from the next big job I do....unless I start posting some "Friday's Horrors" from the resi. world I seem to be inhabiting now.