Greetings from a first time poster. I would like to hear some opinions on your prefered methods for running an underground service or feeder to a subpanel such as to a pole building or other out-building. Do you prefer 3 wire or 4 wire when you have a choice? Do you use a cable assembly or run individual conductors in conduit? What type of cable or conductors? CU or AL. I hear many different arguements on this one here in central Michigan, particularly on when you need 4 wire vs. 3 wire. Thanks for any input, Ed.
I prefer to use a 4 wire installation. It will remain in complince should a conductive path be established between both buildings sometime in the future.
I have rarely had to replace an underground feeder that was installed in a raceway. I have replaced or repaired quite a few direct buried cables, usually type USE, not UF. I think it usually comes down to workmanship (not nicking the insulation & making sure the first 6" of backfill is free of rocks). I'll personally stick with single conductors in a raceway.
Most folks will jump on the savings offered by Aluminum. Since I'm the one doing the pulling, I like it also. Workmanship is very important with Aluminum conductors. I haven't had any failures that I know about.
[This message has been edited by Tom (edited 03-26-2002).]
Few things are harder to put up with than the annoyance of a good example.
Re: Prefered method for underground SE's or feeders#8554 03/26/0203:43 PM03/26/0203:43 PM
What size feeders are you talking about? I believe it is preferrable to run 4 wires and use a raceway. Just because something is acceptable, doesn't mean it is good design for considerations of maintenance and reliability.
Re: Prefered method for underground SE's or feeders#8555 03/26/0208:32 PM03/26/0208:32 PM
At that size, unless your running hundreds of feet, I can't think of any compelling reason, cost-wise, not to use 4 copper conductors in a raceway (possibly even oversizing the raceway for future considerations).
[This message has been edited by Redsy (edited 03-27-2002).]