MCC In Hydraulics Room

[OhioAviator]

We're in the early stage of designing an equipment room for a new hydraulic scrap metal shear. The hydraulics room will contain 6 hydraulic pumps in the 100 to 150 HP range with operating pressures of 4000 to 6000 psi (250 to 400 bar). The pumps will be powered by 480 Vac electric motors. If the motor control center (MCC) were to be located in the same room with the hydraulics equipment, the closest hydraulic line would pass within 5 feet of the motor control center and the closest hydraulic pump would be about 10 feet away. My preference is to NOT locate the MCC in the same room with the hydraulic equipment, but rather put the MCC in a room that is separated from the hydraulic room. I am getting some push-back from management concerning the added costs of putting the MCC in a separate room.

I have several questions...
(1) Is the hydraulic room a classified area according to the National Electrical Code?
(2) If so, what is the exact classification?
(3) What does the NEC say regarding this situation? Will the NEC prohibit locating the MCC (NEMA 12 enclosure) in the same room with the hydraulics?
(4) If so, can anyone cite the specific code sections?
(5) If the NEC doesn't prohibit locating the MCC in the hydraulics room, are there any other general requirements?

Thanks! Any constructive comments appreciated.

 

[dpc]

See NEC Article 110.26. NEC requires dedicated "space", not a separate room.

Separate room is better, but NEC does not mandate this.

With increased concern for arc-flash safety, it is much easier to be in compliance with PPE and arc hazard boundaries if all 480V gear is in a separate room.

I don't think hydraulic fluid would create a classified area.

 

[OhioAviator]

Thanks dcp.

What about the circumstance when the hydraulics pressure lines, couplings, pump, valves, etc. springs a leak under pressure, thereby emitting hydraulic fluid in the form of a mist? I know that doesn't happen under normal operating conditions but it Does happen occasionally. Does the NEC address that circumstance? I can't find it in there if it does.

Again, thanks!

 

[dpc]

Don't think so. Classified areas per NEC and NFPA are based on risk of combustible gases and combustible dust. You can check Article 500 for listing of Class I Groups and see what you think. I don't know the volatility of hydraulic fluid, but I'm guessing it isn't very high.

I suppose an area subject to getting sprayed with hydraulic fluid would not be suitable for NEMA 1 or NEMA 12 MCC, but since this is not a normal occurence, I think that is a stretch.