[toolsallaround]

Is this safe?

EDIT: cant post pics...

 

[toolsallaround]

Current configuration: www(dot)i.imgur.com/S8mtEJK.png

Shed mod, is this safe? www(dot)i.imgur.com/BRvfBfc.png

Thank you

 

[joed]

Yes. You can't have 30 amp circuit/cables protected by 60 amp breaker.
Go to the garage or the panel for the shed source.

 

[Speedy Petey]

Joe, I get the impression that the 30A in the house is the feeder breaker and the garage is the load. If so that is fine.

 

[Luke M]

You're very restricted in what you can do with a 30A circuit, since everything is made for 20A maximum, e.g. sockets. So my advice is, don't do it that way.

 

[joed]

I had to get up close to the screen to see the 30A note at the house. If the house is a 30 amp feed you are fine as long as you put only 30 amp receptacles in the shed. No lights, or normal 15 amp receptacles unless you install a 120 volt sub panel with 15 amp breakers.

 

[toolsallaround]

Thanks guys.

The house feeds the 120v 30A lines from two 30A breakers in the house panel. The switches are connected so they trip together/eachother.

I'm not 100% sure how the garage is wired (new house purchase, garage has drywall) but it has a sub-panel with three 15A breakers. These three breakers are labelled: Door Opener, Plugs, Lights. I haven't found a 240v plug yet (would it even make sense to have 240v 15A?), but there is a large shelving unit that needs to be removed. Maybe it is just a 120v sub-panel... I'll pop the garage panel open tomorrow and check the colours and compare to the junction box.

If I do the modification shown above and feed the shed 120v 30A I will indeed put a sub-panel in the shed with two individual 15A breakers. One breaker will just have two lights on a switch, the other will be a single receptacle.

 

[Speedy Petey]

You're very restricted in what you can do with a 30A circuit, since everything is made for 20A maximum, e.g. sockets. So my advice is, don't do it that way.

Can you explain what you mean by this? It makes no sense.

 

[Speedy Petey]

If I do the modification shown above and feed the shed 120v 30A I will indeed put a sub-panel in the shed with two individual 15A breakers. One breaker will just have two lights on a switch, the other will be a single receptacle.

Personally I'd just run a 20A multi-wire circuit to the shed from the garage panel. That'll give you two 20A circuits to work with, which should be more than enough for a small shed.

 

[Oso954]

......since everything is made for 20A maximum, e.g. sockets. So my advice is, don't do it that way.

And my advice is, don't call a receptacle a "socket". While I know you mean "wall socket" (receptacle), others may be wondering about lamp sockets, etc.

 

[Luke M]

Can you explain what you mean by this? It makes no sense.

It's not relevant since he's planning to put in a panel, but I meant that common things that he'd probably want to use like common duplex sockets, GFCI sockets, etc. either aren't available in 30A versions, or would be hard to find.

 

[Luke M]

And my advice is, don't call a receptacle a "socket". While I know you mean "wall socket" (receptacle), others may be wondering about lamp sockets, etc.

Yeah yeah you're right, but receptacle is a mouthful and I spell it wrong every time.

 

[toolsallaround]

Turns out there isn't a 240v receptacle in the garage. The 240v 60A feed was literally installed just to run the sub-panel (three 120v 15A breakers). I don't get it. Overkill? The previous owner was a DIY guy but there are a few things throughout the house that are questionable (upstairs bathtub isn't supported properly for example, caulking cracking all around).

I'm now considering rewiring the garage (eventually, like next year). Either give it a proper 240v 30A receptacle so I can run a welder, or strip it all down to 120v 20A (remove 240v feed from house).

Personally I'd just run a 20A multi-wire circuit to the shed from the garage panel. That'll give you two 20A circuits to work with, which should be more than enough for a small shed.

I would if I could. The garage is finished, I don't want to start tearing down drywall just to run some shed lighting. The outside junction box is completely accessible and is ~15 feet from the shed. Pulling 120v 30A from the junction box is the simplest solution.

 

[Oso954]

The 240v 60A feed was literally installed just to run the sub-panel (three 120v 15A breakers).

What 60 amp feed? According to your diagram it's a 30 amp feed. The fact that you have a panel that is rated for 60 amps doesn't change the 30 amp feed.

What size is that outside junction box ? It might be too small to add 4 more conductors. You need to detireman the cu in capacity and do a fill calc on it.

If you do come off of there, you will need a subpanel in the shed so you can mount 15 or 20 amp breakers to reduce the circuit amperage.

I think the 20 amp MWBC off of either of your existing panels is the way to go.

 

[Speedy Petey]

It's not relevant since he's planning to put in a panel, but I meant that common things that he'd probably want to use like common duplex sockets, GFCI sockets, etc. either aren't available in 30A versions, or would be hard to find.

Luke, sorry to sound harsh, but you don't know what you're talking about.

"Common" duplex receptacles are either 15 or 20 amp configuration. Same goes for typical GFI receptacles. It's not that they are not "available" in 30A versions, it's that 30A is different from 15 or 20A. There is NO such thing as a 30A receptacle that will even accept a 15A plug. It's not that they are "hard to find", it's that they don't exist.

 

[Luke M]

Luke, sorry to sound harsh, but you don't know what you're talking about.

"Common" duplex receptacles are either 15 or 20 amp configuration. Same goes for typical GFI receptacles.

Let me try again. You can put a 15A receptacle on a 20A circuit, but it's not legal to put a 15A or 20A receptacle on a 30A circuit. Do you still disagree?

It's not that they are not "available" in 30A versions, it's that 30A is different from 15 or 20A. There is NO such thing as a 30A receptacle that will even accept a 15A plug. It's not that they are "hard to find", it's that they don't exist.

That was my assumption, but I've never looked for such a thing. Though of course, you could always use an adapter if you had to.

 

[Speedy Petey]

Let me try again. You can put a 15A receptacle on a 20A circuit, but it's not legal to put a 15A or 20A receptacle on a 30A circuit. Do you still disagree?

You can put two or more 15A receptacles on a 20A circuit. Neither can be on a 30A circuit.

That was my assumption, but I've never looked for such a thing. Though of course, you could always use an adapter if you had to.

An adapter would likely not be listed or complaint, other than maybe an adapter for an RV receptacle. You CANNOT have a 15 or 20A receptacles fused or breakered at 30A.

 

[toolsallaround]

What 60 amp feed? According to your diagram it's a 30 amp feed. The fact that you have a panel that is rated for 60 amps doesn't change the 30 amp feed.

My mistake. I thought amps were added together how volts are added together. So two 120v 30A lines = 240v 30A, correct?

What size is that outside junction box ? It might be too small to add 4 more conductors. You need to detireman the cu in capacity and do a fill calc on it.

Four? I only need to add three (L1 hot, neutral, ground). There's room for three more wires.

If you do come off of there, you will need a subpanel in the shed so you can mount 15 or 20 amp breakers to reduce the circuit amperage.

I think the 20 amp MWBC off of either of your existing panels is the way to go.

Could I just swap the 30A two-pole breaker in the house with a 20A two-pole breaker? Bringing the entire circuit down to 20A and eliminating the need for a sub-panel in the shed. The lights and receptacle in the shed would run off of a single 20A circuit.

I won't be using anywhere near 20A in the garage or shed in the near future. If I ever buy another welder or need more amps in the garage I will rewire.

 

[Luke M]

You can put two or more 15A receptacles on a 20A circuit. Neither can be on a 30A circuit.

Okay then. That's really all I meant to say originally. Sorry for derailing the thread.

An adapter would likely not be listed or complaint, other than maybe an adapter for an RV receptacle.

Possibly if it had a a 15A or 20A fuse integrated.