I'm wiring a small outdoor workshop (Structure separate from the house) with two 20 amp circuits. Now, I know I need to have a master cut-off power switch through which all my power enters the workshop.
My question is.....If I have two 20 amp circuits entering the shed, do I have to have one or two switches for the master switch(s) upon entering the workshop? If just one, does anyone know what type of capacity or type of switch can handle two 20 amp circuits?

Thanks in advance, Troy

I had an electrician out to estimate the job and he only mentioned a master switch and nothing regarding a possible subpanel.

Thanks for the response

it means that each of the 20 amps circuits are on different legs of the 120/240 V service, and a single double pole breaker is used to feed the circuit.

A single double pule switch can be used if you want a single switch to kill all the power to the shed (even in the shed).

You should be aware theta the branch circuit to the shed would no be a 120/240 V circuit.

Any loads from either hot leg to the neutral will be 120 V, while 240 V would be available from hot-to-hot.

So I have to use two 12/2 wires on a single double pole breaker connected to a single double throw switch.......

and the possibility of using a single 12/3 cable to feed both circuits isn't code "wise" right? I've seen wiring diagrams illustrating this possibility.

Thanks!

Let me clarify a bit....this will be more of a craft-y workshop and not so much a wood or metal type workshop in the traditional sense of what most people may think of. Basically, two twenty amp circuits is more than plenty when it comes to usage here for my situation. There are only going to be 6 outlets and 3 light fixtures on both these circuits. In fact, I may have been able to get by on only one 20 amp circ.

Having said that, would you still recommend a subpanel? I'm really trying to keep this as simple as possible and wondering the best possible wiring scenario.

To recap.....I'm wanting to run two 20-amp circuits to an outdoor shed/workshop and wondering what type of breaker, wire, and master cut-off switch to use.

Be sure to include a GFCI protection in the circuit.

Perfectly acceptable.

Since the hots are on opposite legs they can share a neutral.
The neutral only carries the difference in the current on the two hot lugs.

You do need to make sure the "cable" is rated for wet locations since underground conduit is wet by definition and use in a conduit system.

Separate THWN wires are a lot easier to pull.

Because I've got a lot of elbows in my conduit run from the house to the shed, I'm thinking about using THHN or THWN wire instead of UF (I'm pulling the wire through conduit under a deck for the first portion of the run from the house and then going underground from the deck to the shed for which I'll use UF for that). Does anyone know which would be best for this application?

Thanks

With a multi-wire branch circuit you have the 240 right there. I wired my previous garage with a MWBC and wired up a 240v outlet between the garage doors so in the summer I could take my radial arm saw out in the sunshine.

The electrician who estimated the job said he would use THHN for the run under the deck, then transfer to UF. My only idea for using THHN would be for the higher temp rating as compared to THWN because the wire isn't underground (therefore subject to more heat build up). But I read THHN is rated for damp locations, just not wet like THWN.....Any ideas?

Would THWN be the best all around for the "under deck" run as well as the underground portion (i'm attaching the conduit to the deck, not in the gound, under the deck)? Does it matter at all (wire choice)if I'm installing a small junction box at the outer edge of the deck?