Computer room raised floor 50amp locking receptacle.

[J_Rubino]

Hi guys,

Im new to the forum. Im currently involved in a government project where i have a raised computer room floor with a liebert unit and a large ups. Those however are not my issues, I need to install 6 50 amp 250v single phase twist locks under this floor that are going to supply one rack of equipment. So that means they will all be crammed under one 2x2 tile or roughly that area. I'd like to streamline it as much as possible but cant seem to find any way of attaching maybe a piece of liquitight to a twistlock receptale rather than putting them in a box then installing a receptacle. I feel it will be really crowded that way as opposed to a seamless cord type connection. the existing stuff actually has m.c. stuffed in the cord cap which is horribly installed, and im unsure about running long runs of sj or so under the floor. When i say long runs i mean 15' or so. This portion of the project was not specced or engineered so im on my own and first and foremost i want to do whats right. does anyone have any ideas?

 

[TOOL_5150]

Use a FS or bell box on the end of the liquidtight. installing a 50A connector on the end of the LT would be a violation. I do think you can run SO cord and a connector under floor tiles though.

~Matt

 

[LarryFine]

I envision a row of 4"sq's bolted to a stick of strut.

 

[iwire]

If you use cord it would have to have a DP rating.

If you make your own LFMC whips the boxes have to be secured and the LFMC must not have more than 360 degrees of bend.

If you where to purchase factory made LFMC whip / box / receptacles you could install them like cord, just throw them under the floor.

Me, I would likely run 8 AWG MC cables to boxes mounted on a strut (As Larry mentioned) I would bolt the strut to the floor legs so the receptacles faced sideways not up.

 

[J_Rubino]

Those ae great ideas this IT guy thinks i'm going to be leaving 20' of slack so he can move things around himself in the event of equipment being swapped around which I wont be doing. So i know when he sees them bolted to the legs or some strut he is going to go nuts. Also just so i was clear i envisioned a 3/4 piece of LFMC with a straight connector possibly threaded into an adapter of the 50 amp twist lock. Had hubbell actually made such a thing i dont see how it would have been a violation the LFMC can hold 4 #10's i believe. But not possible i guess. What do you guys see more of under floors M.C. LFMC or SO?

 

[J_Rubino]

I apologize 4 #6's i believe in a 3/4 LFMC

 

[iwire]

Those ae great ideas this IT guy thinks i'm going to be leaving 20' of slack so he can move things around himself in the event of equipment being swapped around which I wont be doing.

That is common and can be done with listed factory made whips.

just so i was clear i envisioned a 3/4 piece of LFMC with a straight connector possibly threaded into an adapter of the 50 amp twist lock.

If you can find listed version god bless but the LFMC would have to be secured to the building.

What do you guys see more of under floors M.C. LFMC or SO?

When they are new I see EMT and LFMC, once some time goes by you will find anything.

By the way you mentioned it is a Govt job, usually they have everything specified.

 

[J_Rubino]

Yes you would think. But the engineering firm has screwed up more times than you could possibly believe. One example is of a 160amp 3phase 480volt UPS that is specced to be piped in 4" and fed with 350 MCM. But thats just the tip of the iceberg. More than just the electrical has been terribly screwed up there is a 500 KW genset that was fed with a 2" gas line come to find out the gas needs to be ripped out and redone in 3 possibly 4" to get the desired volume and pressue to support the load. We have made 3 attempts to load bank with no success. Also problems with liquid lines to the dry coolers and pumps on the roof. I have seriously never ever seen more go wrong on one job in my life. That is why it is important to me that what i do that isnt specced out is definitely done right.

 

[steve66]

Hi guys,

I need to install 6 50 amp 250v single phase twist locks under this floor that are going to supply one rack of equipment.

If I understand what you are saying, that's just insane. Nowhere other than a goverment job would they run six 50 amp circuits to a single rack. Either only a fraction of that power will ever be used, or that rack will melt down.