I am assuming he didn't put in a sub panel in the shed was to save me money?
Didn't save much money. 30A #10 copper is about the same price as 90A #2 aluminum, and at such large sizes, alumium is known to be reliable. With three #12, it was "six of one, half dozen of the other" costwise to go with 3 circuits vs #2 feeder + subpanel.
The only trick is that box with the splices where your buddy switched from Romex to THWN/XHHW individual wires. Your guy used 5 cent wire nuts. But there's no cheap option to splice #2 SER (indoor loose in walls) to #2 THWN/XHHW (outdoor/conduit). You're talking Polaris at $25 a pop x 4. There is no good option I'm aware of that will work both loose in walls and also outdoors in conduit.
He did it because he didn't know how to do it correctly.
A larger feeder, a sub panel just may have been cheaper than the extra circuits he ran.....which won't satisfy code.
But since it is in conduit.....it can be fixed (done correctly).
That will open up a lot of possibilities for lighting, outlets and heat.
Yes, to correct the faults, two things will be needed. #1 mandatory disconnects. at the entrance point to the shed, you'll need a 3-gang box (or two 2-gang boxes) and put 3 switches there all close together. The 120V lines can be 20A rated switches, the 240V line must be a
2-pole 20A rated switch.
#2 make "two 120V circuits to a shed" legal by making one of them a switched line, nominally for remote control of lights. The switch must be in the house.
In a wood working shop there is often a warning . If it gets to a hi enough dust density point occupants will develop a cough but usually don't connect with the reason . Those shop dangers of explosion are un-heard of but i suppose it's possible .
Are you kidding me? It's HUGE. USCSB (Chemical Safety Board) has
dozens of accident breakdown videos on Youtube where people were totally oblivious to the risk.
It's usually a double explosion. Over years, dust accumulates on walls, ceiling and every nook and cranny, top of pipes, bottom of I-beams, you name it. The first explosion is limited but it throws a shock wave through the whole building. That shakes dust off all those places. Now dust is raining down in curtains throughout the building, you guessed it, a Much Larger explosion hits that does all the damage. If they had power-washed their walls, ceiling and nooks and crannies every evening the 2nd explosion would not have occurred. The survivors are always surprised that it could even happen.
With the dusty conditions any kind of heat scares hell outta me other than hot bricks for heat .
In other words, you don't want high-temperature heat sources. WELL... AHEM.
#1 the baseboard heaters OP already rejected are notorious for running cool because they have a huge surface area. They
expect children to poke their fingers in there and are cool enough that's not a big problem. They will accumulate some dust but just blow them out every once in awhile with compressed air.
#2 the indoor unit on a mini-split heat pump is also gigantic, (because it must also work in A/C mode when temperature diff might only be 30 degrees, freon vs ambient) ... so it's only getting up to 140-160F, and can't get much hotter because of how freon works.
Of course everyone is recommending blower-driven fans with hot elements that glow cherry red. I guess if it's not glowing cherry red, it's not actually heating because God forbid we get useful heat from something that's only 140F.
It won't be that bad. Just a small Workshop in a 200 square foot shed. I've got doors windows
Not in heating season, you don't.
I received a shock with that one. The metal heater.
Coz they're junk. Bet it has a 2-prong plug also. 2-prong plug = metal case isn't grounded.
