How to lengthen feed wires for subpanel

[packerguy®]

My subpanel in my shop is full. Its a 60A (IIRC its fed with singe 4 gauge wires, underground in conduit) When I moved in years ago, I looked it over to upgrade the panel to one with more spots (wanting to add an additional 220V circuit) but the feed wires are JUST long enough and the new panel has to be moved over to fit (not enough room between the studs....last cavity against the house wall)


I have 2 220v outlets in the shop off the subpanel that has worked fine to this point. One is for the tools (only use one at a time so its no problem. The other is for my 5000w heater. There is a 5L30P plug on it so it can be unplugged, so now that I got a 3hp dc, I am sharing that outlet between the DC and heater. Not a problem, just a pain. It would be nice to get a dedicated outlet for the DC but back to the problem of no space in the existing panel. 

So to get the larger one, I need to lengthen the wires. Obviously I could pull new wires, but I am not real excited about that.....probably 70 feet with 3 90 degree elbows....and #4 wire.....sounds like a blast 


I remember on Ask This Old House years ago they ran a subpanel to a garage, that was like 150' away from the main panel in the house...they used under ground feeder cable, and instead of running the wires directly to the subpanel, the did some sort of connection (similar to the wago connectors I think) as soon as the wires entered the building then ran from that to the subpanel. 

Is this a solution I could use or is there another easy way short of running new feed wires?

[Bob10]

My subpanel in my shop is full. Its a 60A (IIRC its fed with singe 4 gauge wires, underground in conduit) When I moved in years ago, I looked it over to upgrade the panel to one with more spots (wanting to add an additional 220V circuit) but the feed wires are JUST long enough and the new panel has to be moved over to fit (not enough room between the studs....last cavity against the house wall)


I have 2 220v outlets in the shop off the subpanel that has worked fine to this point. One is for the tools (only use one at a time so its no problem. The other is for my 5000w heater. There is a 5L30P plug on it so it can be unplugged, so now that I got a 3hp dc, I am sharing that outlet between the DC and heater. Not a problem, just a pain. It would be nice to get a dedicated outlet for the DC but back to the problem of no space in the existing panel. 

So to get the larger one, I need to lengthen the wires. Obviously I could pull new wires, but I am not real excited about that.....probably 70 feet with 3 90 degree elbows....and #4 wire.....sounds like a blast 


I remember on Ask This Old House years ago they ran a subpanel to a garage, that was like 150' away from the main panel in the house...they used under ground feeder cable, and instead of running the wires directly to the subpanel, the did some sort of connection (similar to the wago connectors I think) as soon as the wires entered the building then ran from that to the subpanel. 

Is this a solution I could use or is there another easy way short of running new feed wires?

You don't say how far you have to move them so not sure what you have available for space.  You could add a junction box where they end now and tie on to get the length you need.


Edit to add I did something similar where are pulled all the wires from the breaker box to a spot close to the kitchen and tied everything from the kitchen into it.  I was much easier than pulling from the panel to each circuit

[fixtureman]

I would try a junction box and use split bolts.

[jerry s]

You don't say how far you have to move them so not sure what you have available for space.  You could add a junction box where they end now and tie on to get the length you need.


Edit to add I did something similar where are pulled all the wires from the breaker box to a spot close to the kitchen and tied everything from the kitchen into it.  I was much easier than pulling from the panel to each circuit

i think you can hook up another panel off your sub panel  jerry

[pprobus]

i think you can hook up another panel off your sub panel  jerry

To the OP:
I'm not entirely clear on what you are trying to do, but Jerry's suggestion that I quoted above, is what I would recommend.  Other alternatives, if it is a larger subpanel you are looking to put in, can you replace some of the 120V breakers with, I am not sure what they are called, but "mini" breakers?  They are normal sized 120V breakers, but with two separate breakers in the same breaker housing.  Two of those would free up two 120V spaces in the panel giving you 1 240V space, assuming you have two 120V breakers side by side, which I believe is very likely unless all the circuits out of that panel are 240V. 

To extend the #4 wire, I had to do something similar when I shortchanged myself on my welding outlet.  I consolidated multiple junction boxes into one large one (16x16 I think) and spliced the welding circuit in there (with wire that large, I do not recommend trying to do this in a normal 4" JB, I'd splurge for a larger one, perhaps 8x8, I opted to go even larger to keep from having to re-run conduits).  It was #6 wire, but I believe Lowes or HD carries splicing kits that can be used on #4 wire too.  It is a kit with a screw hold-down, wire coupling, a length of thick heat shrink tubing and a length of thinner heat shrink tubing.  The only thing is that you need a heat gun or some source of heat (not sure if a hair dryer would work) to heat up the heat shrink tubing.  

This looks like what I used and it appears that it max's out at #4 wire, so it looks like you can use this same product for your situation:  https://www.lowes.com/pd/IDEAL-1-Count-1...ng/3128687

Keep us informed of what you do and don't be afraid to post photos.

[TDKPE]

i think you can hook up another panel off your sub panel  jerry

Yes, he can.  He could put a small sub off of it to serve whatever is near where it would go.

Or a junction box with butt splices or splice blocks to extend the feeder.

Just so you know, if the insulation type of the buried feeder conductors is 75C or 90C, which they probably are (THWN, I'd guess, since it's underground in conduit), then you're legal up to 85A to that panel.  In case you thought you might need to up the ampacity, and as long as the panel is rated for that.  Assuming it's 4-gauge copper.  If it's 6-gauge, then you're only good to 65A, so 60A is appropriate.

Edit: Almost forgot - whatever you use (the OP, that is), be sure it/they're UL listed for the wire size, type, material (copper vs aluminium vs CU/AL), voltage, and application.

[Phil Thien]

Yep add another panel. Or turn the existing panel into a disconnect feeding the new sub panel. That way you can de-energize the entire new sub panel when you work on it.

[srv52761]

Yes, he can.  He could put a small sub off of it to serve whatever is near where it would go.

Or a junction box with butt splices or splice blocks to extend the feeder.
.............

I would go the sub panel route, solves all your problems, maybe...
If you decide to extend I would suggest the splice/distribution blocks that  TDKPE mentioned, cleaner look,  no taping, easier to check, less space than split bolt.

   

From your post, it sounds like your shop is a detached building? (underground conduit) but maybe not? (last cavity next to the house)
Many of those 60 amp panels were lug only with 4 or 6 spaces.  If that is your case, and in a separate building, and your added circuits will mean you have more than 6 throws, and I believe each 240v double pole breaker counts as two ( others may confirm/refute) you will need to add a single throw disconnect.  The 2020 code eliminated the 6 throw rule and requires a disconnect regardless.but not many municipalities will have adopted that yet.
The new code also requires it to be on the exterior.  
If this is your case, the easiest solution would be to add an outdoor rated load center.  Gives you your enclosure, your splicing blocks, your grounds, your disconnect, your additional spaces.

Edit, I type too slowly.... I see Phil touched on the disconnect.

[TDKPE]

The 2020 code eliminated the 6 throw rule and requires a disconnect regardless.

That's new information to me.  I'll have to look into that, as I've not been keeping up lately.  Kind of spooling down a bit at work, and concentrating on other technical areas, though sooner or later I'll get pulled back in.  

[srv52761]

......    as I've not been keeping up lately.  Kind of spooling down a bit at work, and concentrating on other technical areas, though sooner or later I'll get pulled back in.  

When you have a trade skill, spooling down never works out.  As soon as people find out you’re “spooling down” they figure that just gives you more time to do favors for your friends.... usually for free.