Computer room equipment connections

[gmgerry]

I'm back with my computer room saga. The room is now just a room with a separate UPS and HVAC. This includes vents to outside the room from under the floor to outside the room and vents overhead to the office plenum for fresh air into the room.

The new question is the power cable from equipment to the receptacle under the floor.

1. The inspector states that we are not allowed to have receptacles under the raised floor. They are considered hidden receptacles.

2. He also states that we are not allowed to connect to those receptacles with a power cord from a piece of equipment such as server or plug strip. This is because the power cord is PVC.

This is all to weird. 645-22 states that the receptacles do not have to be mounted. It also states that the power cords are permitted under the floor.

I'm I missing something or is this inspector on dope?

I sure wish someone would clear all this computer room stuff because the code is not 100% on this.

 

[dereckbc]

Re: Computer room equipment connections

In order to use the relaxed requirements of 645 you have to meet every requirement of 645.2. Even if those conditions are met some local codes will still not allow the provisions of 645.

From a design perspective most do not want to meet all the requirements of 645.2 especially 645.2(1). So my question back to you is the room designed, stamped, and approved for 645? If not you cannot use the relaxed methods.

If all the conditions are met, and local AHJ adopts 645 without modification, you can run cord-and-plug connection under the raised floor up to 15 feet. But the receptacle box and raceway has to meet 645.5(D) and the methods of 300.11.

You might want to try a couple of methods I have used for data centers.

1. Do not install any whips. Get your C of O. As equipment is installed have electricians install the whips from the PDU?s using EMT to the point where it is under the cabinet, then transition to liquid tight and route inside cabinet and terminate on quad receptacle or term strip. (This is the best method)

2. If you just have to have a receptacle and 645 compliant installations run whip from PDU using any of the approved raceways (I like the EMT/liquid tight combo) to under the cabinet and install a L5-20R or L5-30R. From the receptacle run SO or similar to cabinet with a hard wired quad or term strip.

[ June 05, 2003, 04:41 PM: Message edited by: dereckbc ]