Cable Trench Codes
Cable Trench Codes
(OP)
Does anyone know of a code or standard that applies to installing electrical wire & cable in a concrete trench? The trench was saw cut into a floor and the owner wants to just lay the cable and wire into the bottom of the cut-out and cover it with steel plate. There is some 480vac and 120 control power in there. I don't like it but don't see a code or standard to back up my opinion. I didn't see anything in NEC but sometimes that's like trying to find a needle in a haystack.






RE: Cable Trench Codes
These folks make a pre-cast concrete trench system, so they may have looked into this in more detail: www.trenwa.com
RE: Cable Trench Codes
If the runs are very long, you may be well to do that anyway to reduce interference with the control circuits.
RE: Cable Trench Codes
Cable trenches can interfere with the design of a floor drain system, especially if trench drains are used. The floor should slope away from the cable trench and the trench should have some means for draining any collected water.
RE: Cable Trench Codes
I have also installed tray in trench and allowed to use the ampacity table for cable in tray.
If you install a 2500 KVA transformer at 480 volts a combination of trench and tray works fairly well. It almost impossible to run 4000 amps ( 133% overload ) in a duct bank.
RE: Cable Trench Codes