[waterjet]

I am upgrading the subpanel in our garage with a new 100amp Homeline 6-space 12-circuit outdoor load center. This is on a farm, with a lot of old wiring.

Previously there were two hot wires coming into the old box, supplying 120 voltage, separately, to all the attached circuits.

Can I use the same two hot wires to energize the new box, when using single-pole breakers or should I wire it more conventionally? I believe that it is 10 gauge wire. I was going to connect each hot wire to the two separate lugs on the box and the neutral/ground to the neutral bar on the box. I was also going to add a ground bar and connect it to a ground rod and keep all the ground wires and neutral wires separated.

Do I need to have a ground wire coming from my supply panel, connecting to the ground bar on the subpanel?

Recently, I did rewire the old box and have it attached with only one hot wire, a neutral, and ground wire coming from the supply box that has a 25amp fuse on it. I'm just wondering if this is the best method, since the total amperage needed in the garaged is less than 20amps. I realize that this may require a two-pole main breaker on the box to connect the circuit.

 

[Arrow3030]

Can I use the same two hot wires to energize the new box, when using single-pole breakers or should I wire it more conventionally?

I'm not sure what you mean by more conventionally.

You should have a grounding conductor feeding this panel. There was a time when grounding conductors weren't ran to remote buildings and this may be the case.

If there is any way to get a grounding conductor to the feeding panel, it should be done. If it isn't possible to do, you can bond the neutral to the ground at your new sub.

 

[waterjet]

What I meant by, conventionally, was to us the neutral wire as an actually neutral and not as a hot wire to increase amps on sub panel, which is probably not recommended. I've read that you want to supply about 20% more amps than your maximum pull.

 

[joed]

A wire is not called a neutral just because it is white.
You are confusing me. How many wires do you have coming into the panel from the house? What colour are they? What size are they? You say the neutral was being used as a hot. This would seem to indicate you only had two hot wires and no neutral.

 

[Run and find ou]

Is it an attached garage or a detached garage?

 

[waterjet]

The garage is detached. I've decided to feed this new box from a different source. A single 50 amp breaker box that is approximately 50-60 feet from the subpanel. The current wire feeding the old box looks like 10 gauge 2-wire with ground wire. The subpanel lists either 6 or 8 as the smallest size for the lugs. What would be the most economical and still be safe?

Arrow was talking about a grounding conductor. Does this mean a ground wire coming from the feed box that is attached to the neutral or ground bar on the subpanel? And if not possible, grounding the subpanel seperately, which I read should have a separate ground bar installed to do this; or are you recommending bonding the neutral to the box with a ground wire attached?

And Joed was asking me about the old hook up. I didn't like it and rewired it last weekend. There was an old fuse box, as the supply box, that had four breakers in it. The black wire was attached to one breaker and the white to another and the ground wire was attached to the neutral bar. The wiring in the subpanel was too confusing that's why I tried everything and decided to get a new box that could accommodate at least five circuits.

 

[joed]

If you run a new cable you must remove the existing wire. You are only permitted one feed to a detached building.
You didn't say what the loads will be, so it's hard to say which size cable you need. You definitely need a four wire feed with two hots, neutral and ground.

 

[waterjet]

I added up the loads and it is around 16amps at present. Would like to have room for expansion and read that you should add 20%. I think that 30amps should be more than enough.

Is the four wire you are describing the same as 3-wire with ground wire?

 

[joed]

Is the four wire you are describing the same as 3-wire with ground wire?

Yes, three wire plus ground.

If 30 amps is enough then a 10/3 cable will be all you need. That gets you 30 amps on both hots or 60 amps total at 120 volts.

 

[Jim Port]

If the minimum wire size is listed as #6 that is the smallest wire you should have in the lug. You could pigtail a piece of #6 to the #10 .

 

[joed]

If the minimum wire size is listed as #6 that is the smallest wire you should have in the lug. You could pigtail a piece of #6 to the #10 .

Or change the lug if it is removable. Some of them are bolted on and can be changed.

 

[waterjet]

If I pigtailed the 6 and 10 gauge wires together, what would be best for doing this?

 

[waterjet]

Just looked at new box again and it says that main terminals are suitable for no. 8 to no. 1 wire. Had seen no.6 somewhere else on the box.

 

[rjniles]

Wire nut. Or Polaris connector(pricey).

 

[Jim Port]

A large blue or grey wire nut is the cheapest and easiest.

 

[waterjet]

I really appreciate all of your help on this. Some time in the near future I would also like to upgrade the service wire that runs from our meter to the house. It's 200amp and can't decide if I want to keep it above ground or bury it. Above ground would be shorter and require a smaller wire where as burying it would be a longer run and require much more work. Any suggestions on size?

 

[rjniles]

I really appreciate all of your help on this. Some time in the near future I would also like to upgrade the service wire that runs from our meter to the house. It's 200amp and can't decide if I want to keep it above ground or bury it. Above ground would be shorter and require a smaller wire where as burying it would be a longer run and require much more work. Any suggestions on size?

What are you planning on upgrading to? Do you need more than 200 amps?

 

[waterjet]

Concerning the 50 amp breaker I'm installing in the garage. I have the 10 gauge 4-wire, the breaker box, and breakers. What I need to know, is, how is a 120 volt, 50 amp breaker typically wired? I was going to put in a main breaker, but I don't think that I can when wiring with two hot wires on each side of the box. I had six, 15 amp breakers to fill every spot on the box, then I purchased one two-pole 50 amp breaker to use as the main breaker for the box, but I don't think this will work, because wouldn't that give me 220 volts?

 

[waterjet]

Upgrade

What are you planning on upgrading to? Do you need more than 200 amps?

Our main idea is to upgrade the size of the wire, because the current one is too small, but we may also have a new meter installed and run the wire underground, directly to the panel, as it should be. So it's bigger than just a new wire, but we some disagreement on the size. I was looking in an older electrical contracting manual and used their tables to determine the size. Based on a 4% voltage drop, it recommends 250 to 350, depending on the type of aluminum wire and 4/0 to 3/0 to 250 if using copper for a 100 foot run, underground. Does that sound about right or have things changed drastically since 1983 when this Craftsman manual was written?

 

[waterjet]

Conflicting Information

Wire nut. Or Polaris connector(pricey).

The funny thing about this breaker box is, that when I removed the connectors, it listed on the connector that they can be used for 14 to 1 wire. Not sure why the box says differently.