Latest Discussions : Electrical & Lighting

sgoodno

10:44AM | 11/27/05
Member Since: 12/10/03
15 lifetime posts
Hello, I recently had a 60A dual pole breaker, located in my main panel, trip. This breaker fed a subpanel in my guesthouse. In troubleshooting the problem we tracked it down to a short in a splice box near the main panel, which we cleaned and reattached with wirenuts and rubberized tape, for now. We also found a second short where the copper 6/0 cable enters the main panel. One of the hot leads shorted against the bulkhead where the conduit enters the box. Also, temporarily insulated this wire.

The splice box was installed by the PO and houses a splice of 2/0(or 4/0?) Aluminum service feed from the guesthouse to a short 6/0 copper feed to the 60A dual pole in the main panel. I am not sure why the splice was done.

Nonetheless, I want to install a new weather tight junction box, rework the splice within this box and replace the 6/0 copper wire with damaged insulation.

Questions?

Is it ok to keep this splice in the service feed to the guesthouse subpanel? Or should it be all one run of cable from the weather-head to the main panel?

If a splice is okay, what would you recommend in terms of a weather tight box and connectors other than the wirenuts? Is there an aluminum paste that should be used on the Al service cable to prevent corrosion? Lastly, what sort of insulation tape should I use around the new splices?

Thanks!

Scott

MistressEll

07:11PM | 12/07/05
Member Since: 01/30/05
360 lifetime posts
you may NOT "splice" copper directly to aluminum! you may NOT wire-nut your main supply. you will NOT achieve effective "insulation" with electrical tape.

*I have no idea what "the PO" is.

Call in someone QUALIFIED to do this work for you.

"Electricity is an equal opportunity killer".

househelper

04:12AM | 12/08/05
Member Since: 03/31/05
265 lifetime posts
I assume you mean #6 wire as there is no such animal as 6/0. Also check your wire size for the"2/0(or4/0" you mention. You should not splice Al and Cu without special connectors. Are you sure it is Al? Some older SE cable looks like Al but is actually Cu with a silvery coating to prevent the insulation from reacting with the copper.

High quality electrical tape (Scotch 33+) can work as an effective insulator if properly applied.

There are set screw type connectors that will work for your application, just make sure they are rated for Cu to Al connections. Better to replac the feed with a continous run of 4 wire #6 copper.


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