# Control room inside and MCC



## gpop (May 14, 2018)

NFPA 70E has rules about authorized entry into a mcc, They have further rules if the voltages are above 600. I can not see how a operator would be a qualified person. 

There are other rules about occupancy and egress that would also probably go against using this space. 

I thought all company's had got to the point where a mcc has to remain locked to avoid operators from entry.


----------



## John Valdes (May 17, 2007)

Welcome to Electrician Talk.
Thanks for taking the time to fill out your profile.

Are you typing on a keyboard unlike the American English type?
I'm just curious. What are those special characters?


----------



## MikeFL (Apr 16, 2016)

it's the apostrophe. 
certain programming languages have that fart embedded. kind of like the &amp to denote an ampersand.


----------



## joebanana (Dec 21, 2010)

I'm surprised they asked. We used to find scaffolding planks between two chairs, behind the switch gear in the MCC's. Complete with newspaper blankets.
There's no code section that addresses this particular issue, but the company policies do.


----------



## lighterup (Jun 14, 2013)

I would think working clearances would settle this issue as most 
MCC rooms aren't that wide to begin with , usually engineered to 
minimum standards as to not waste potential sq ft space in the 
plant.


----------



## Easy (Oct 18, 2017)

My question would be why does an operator want his desk in the same room as an MCC ? The MCC is normally controlled from the area it serves. If you had an exhaust hood in a lab and you wanted it to come on you would not want to go to the electrical vault to turn it on. 4160v probably has specific guide lines about this. Even at 480 volts you can get seriously injured if you were in front of an faulty installation and energize it. Don't put unauthorized people in places where they don't belong. You may also want to refer to OSHA requirements as well as NEC. Unqualified persons may not enter the rooms or spaces while the electric supply lines or equipment are energized. I once saw a video where an operator heard a buzzing noise coming from one of the buckets of a motor control center. What's he do ? He puts his ear up against the enclosure to isolate where the sound is coming from. Right at that exact moment there was and explosion. He was seriously injured. So just be aware of the potential danger.


----------



## Wiresmith (Feb 9, 2013)

show them the youtube videos where the room ignites


----------



## paulengr (Oct 8, 2017)

Easy said:


> My question would be why does an operator want his desk in the same room as an MCC ? The MCC is normally controlled from the area it serves. If you had an exhaust hood in a lab and you wanted it to come on you would not want to go to the electrical vault to turn it on. 4160v probably has specific guide lines about this. Even at 480 volts you can get seriously injured if you were in front of an faulty installation and energize it. Don't put unauthorized people in places where they don't belong. You may also want to refer to OSHA requirements as well as NEC. Unqualified persons may not enter the rooms or spaces while the electric supply lines or equipment are energized. I once saw a video where an operator heard a buzzing noise coming from one of the buckets of a motor control center. What's he do ? He puts his ear up against the enclosure to isolate where the sound is coming from. Right at that exact moment there was and explosion. He was seriously injured. So just be aware of the potential danger.




Be careful here. Energized is NOT the same as exposed. If that were the case no one could enter a room with lights or a light switch. The boundary is 3’6” even if it’s exposed. That’s under 600 V.

Above 600 V (outside US above 1000 V) the equipment must be protected by some sort of tool to gain access (wrench, screwdriver, lock) and even within the equipment due to insulation requirements the bus, switching equipment, and controls sections are physically isolated from each other.


Sent from my iPhone using Tapatalk


----------



## Easy (Oct 18, 2017)

Just be careful out there. This guy apparently was just investigating a sound coming from the MCC.. Doors closed and No live parts exposed. The video is kind of grainy so it's hard to tell what the voltage is. Note the table and other furnishings.


----------



## Easy (Oct 18, 2017)

I think the other point here is can stuff be stored in electrical rooms. The fire marshal in my area has a fit if anything is stored in an electrical vault or fan room for that matter. Even electrical parts like boxes of florescent tubes can't be stored or kept in vaults. It's a fire hazard and even more important it gets in our way when we need to do work. Smaller locked electrical rooms in commercial buildings always have junk stored in them. even buckets and mops used by janitors. Everyone has a key. That's probably a gripe we all have.


----------



## Southeast Power (Jan 18, 2009)

Usually electric and equipment room are designed for equipment not people.


----------

