vogelaar
Nov 10, 2006, 11:29 PM
I am in the process of re-wiring my house. My load center used to be located on the outside of my house. I have now moved the load center (200 amp sq d qo panal) to the inside, and am looking to place a 200 amp disconnect next to the meter pan. I was told I needed to get 2 awg 3 cond with ground to run from the dieconnect to the load center. I recently went to the local supply house to buy 2 awg 3 cond with ground romex, because I was told the wire needed to be in a jacket. I was told at the supply house that they do not make 2 awg 3 cond with ground romex, and I would have to run it in Allum. I would rather not run Allum. I would like to run copper if possible. Can anyone tell what my options are.
Thanks in advance
Jim
tkrussell
Nov 11, 2006, 06:15 AM
It is a good thing that you did not listen to the person that told you to use #2/3 cable for a 200 Amp service, as #2 copper is rated to handle anywhere between 95-130 amps,depending certain specifics.
There may have been a misunderstanding, as #2/0 copper is allowed for a residential 200 amp service. Or you can use #4/0 aluminum.
If a cable assembly is made using #2/0Cu , it is not widely available, so if you want to use copper you may need to run conduit. Besides, copper is very expensive now. Also, if any cable will be outdoors the sheathing needs to be sunlight resistant, and Romex is not.
So, for 3-#2/0 THHN or XHHW cables and 1-#6 cu for the equipment ground, you need 2" conduit, Sch40 PVC is probably the most available and the easiest to work with.
If the disconnect can go close to the meter, you can use 2" conduit nipples, locknuts and bushings between both and use #2/0 Cu between the meter load side and the disconnect line side.
What is widely used and available for residential 200 amp service is #4/0 SER 4 wire aluminum cable. Aluminum is very popular for large amperage feeders.
The issue with Al wire is to be sure to treat the connections properly, by wire brushing, applying anti-oxidant compound, and proper torqueing the connection. Any disconnect, panel, and meter will list the torqueing specs for their connectors, which must be followed with both Cu and Al cable.
See the following spec sheets found at www.alcan.com: