Sparky Question.........

Stuart Ablett

Member
Messages
15,909
Location
Tokyo Japan
OK, guys, how many 20 amp circuits are usually allowed on a 30 amp service?

I'm going to buy a new panel for the Dungeon, and don't want to over do it.

No light gauge wiring, all #12 or #10 wire.

No real power hogs in the Dungeon on the 100V circuits, the small bar fridge, (11 amps max), SCMS, TS, lighting and then hand tools, oh yeah, the lathe too, which is 15 amps max.

Cheers!
 

Greg Cook

Member
Messages
2,882
Location
Tokiwadai, Japan
Stu,

By "20A circuits", do you mean 20A sockets? or actual 20A circuit breakers? I believe 10 sockets on one circuit breaker is the max allowed. I think it's more important for you to layout the sockets/circuit breakers according to their use/current and balance the number that way. The lathe on it's own circuit, saws that would only be used one at a time on the same circuit with multiple sockets, etc..

Also, when you say your lathe is 15A and fridge 11A "MAX", is that including the startup current?
 

Darren Wright

Administrator
Staff member
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17,479
Location
Kansas City, Missouri
Well my assumption is that you are feeding from a main supply somewhere to the room off a 30 amp breaker circuit in the main panel. Your putting a sub panel in that may have multiple 20 amp circuit breakers in the room.

I'm not a licensed electrician, but as long as you've got a 30 amp breaker at the main feeding it and properly sized wiring, you could put as many as you need after it. I might suggest to get a subpanel that has another 30 amp main breaker in it to protect the wire feed from the main supply in the event the main fails to throw.
 

Greg Cook

Member
Messages
2,882
Location
Tokiwadai, Japan
OK, back from some rain gutter work.....

You mentioned lighting... Be sure to put your lights on separate circuits than your equipment circuits. You do not want to pop a breaker and have a saw winding down while you are in the dark...and can't find your way to the breaker! :doh: I would put 2 breakers for lights, just for double peace of mind.

Think about what tools you might be running at the same time, if any. I would put equipment with high start-up current, as well as high running current equipment on separate circuits. Whatever motors you have that can run on 200VAC, I would rewire them to run on it...thus saving you current draw.

Be sure your wall socket and switch specs match your circuit specs as far as voltage and current. Might be a good time to double check all your cords and plugs to make sure they are the right specs for the voltage, current and plug style. This would be good if you happen to use a cord you had on hand for a project, intending to upgrade next time you went to the DIY store.

(circuit = breaker circuit, not wall socket)
 

Stuart Ablett

Member
Messages
15,909
Location
Tokyo Japan
Sorry, it was late and I just fired that off with not much info :eek:

Here is half of my "Panel"


it is indeed a "sub panel" from the main panel.

I know it looks scary, but it is all perfectly legal here in Tokyo. :dunno:

I do have a lot of things on separate circuits, like the lathe, and the fridge, table saw etc. The large tools, the Jointer, The Phoenix, and the cyclone all run on 3-phase of which I have lots of power. Tools that are 100V that I'd be running together are something like the Festool saw and the vacuum cleaner, not much more than that.

So if I buy a panel with 20 spots for breakers, that is OK?

Just checking.
 

Greg Cook

Member
Messages
2,882
Location
Tokiwadai, Japan
Stu,

A 20 breaker service panel should be more than enough, but will give you a lot of flexibility in ways you can wire up the Dungeon now, and in the future. :thumb:

Oh...where is the "main panel"? Any pics of it?

How much current does your elevator draw under a full load?
 

Steve Ash

Member
Messages
2,437
Location
Michigan
Wish my boys were here to answer your question Stu.:dunno:

Jr. is a second year journeyman running a crew and Chris is a 2nd year apprentice.....both work on commercial wiring.

I'm pretty hard to stump on antique John Deere tractors though in case you ever have the need to know.....:rofl:
 

Al killian

Member
Messages
1,941
Location
Floydada, Tx
Wow, stu, I am suprised they let that be legal. My inspector made me pull all the old wiring of the walls before he would approve the new panel.
 

Drew Watson

Member
Messages
2,070
Location
Salt Spring Island, BC Canada
Stu I would suggest talking to a professional electrician that lives in your region and see what they recommend. Clearly your electrical codes are far more lax than what we have here in Canada as what you have would scare most electrical inspectors here. I know that we are limited to a certain # of 30 amp breakers to a panel and that you can wire in 13 outlets to a 15 amp breaker. Of course I have a 150 amp 240 volt service. I am not firmiliar with what the services are in Japan. Sorry I wish that I could be more help.
 

Stuart Ablett

Member
Messages
15,909
Location
Tokyo Japan
Well, just to give you all a laugh, my whole family, both sides are electricians, and my Dad worked for the BC government as an electrical inspector for 30 years :D
 

Stuart Ablett

Member
Messages
15,909
Location
Tokyo Japan
Soooo... This was just a test? :huh:

:doh:


:rofl::rofl::rofl:

Nope, I never said "I" was an electrician, I know the basics, and such, I have no problem with running a circuit or three, heck, I can even wire a 3-way switch, but the specifics of what is "allowed" and what is not, in terms of how many plugs on a 20 amp circuit, or how many 20 amp circuits on a 30 amp sub panel, well, I have to ask, just to be sure. :thumb:

I spent a few hours this afternoon cleaning up the panel area, and double checking a few things.

I DO have one set of lights that run off the main panel, so if I trip the sub panel, I still have lights.

I have the AC on another circuit that comes off the main panel, not my sub panel, which is good, as in the summer between the AC and the fridge starting up, I would be using a good portion of my power.

I'll also say that in the years I've been using the Dungeon, I've never had a breaker trip, not one.

main_panel.JPG
This is what the main panel looks like, this is in the parking area on the first floor.

main_panel_inside.JPG
Here it is open so you can see the guts.

panel_close1.JPG
I've cleaned up the panel area, I finished breaking out the box that is in the wall that the electricians did a poor job of, the box was also about 1/3 full of concrete.

panel_3-phase_open.JPG panel_3-phase_closed.JPG
I next moved and upgraded the 3-phase feed into the panel area.

I put in a larger junction box (I know it is BIG, but I had it on hand, it was left over from something) and I added a breaker/switch for the cyclone.

I'll send my Dad these pics and see what he says, if he has no problem with it, I'll not bother changing anything more.

Sure it would be nice to have a fancy nice sleek panel there, but it looks like it will cost me about $120 or so, and the time to do it.

I know it would not pass in Canada, or the US, but then again, I'm not in Canada or the US :rolleyes:

The local electrician had a look at this when I did it originally, and he saw no problem with it. :dunno:

My dad also said, that being a one man shop, the chances of me tripping a breaker is kind of low, especially with most of my large tools on the separate 3-phase power.

Cheers!
 
Last edited:
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2,369
That's pretty scary looking I must say. Just keep in mind electrical codes...in our country or yours, are not the end all-be all, but merely the minimum required to get the job done.

Where I live I don't even have an electrical inspector, but I over-do everything just to be safe...GFCI's on every outlet but the refrigerator. 20 amp sockets and switches. Plenty of sub-panels....

I will say this though. Its been claimed that they use mice in Japanese food. From the looks of your panel it must be true because you don't even have a steel box to keep the mice out.:rofl:

As for your 3 phase...you suck!! :D
 

Stuart Ablett

Member
Messages
15,909
Location
Tokyo Japan
Aw come on, "MICE" in food.... :huh: :dunno: :rolleyes:

Well, I'm waiting for my Dad to reply to my e-mail, he saw a pic of the panel, and agreed it would not pass in Canada, but, did not see it as being inherently unsafe. He also commented that the loads I would have on my circuits, being a "One Man Shop" would not come close to overloading any of the circuits.

Now I have to decide if I want to, or need to spend the $120 on one of these........

plastic_panel_40amp_20a.jpg plastic_panel_40amp_20b.jpg plastic_panel_40amp_20c.jpg

..........because that is what I'd replace my DIY panel with.....:dunno:
 
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