Planning Electrical Changes - Subpanel and branch questions

[jds62f]

Hi,

I have an existing detached garage, with wiring, but done poorly. I'm at the onset of planning, and i got great answers last time so I'm hoping someone will be gracious again. NEC 2014 is what I'm looking at for my area. I am looking at replacing all of the branches coming from this panel and will be having the work inspected.

Here's the subpanel I have. Power comes in through the bottom left, and leaves primarily out the top (with one exit on the lower right)

Panel Questions

I have 2 40a circuits from the main panel feeding this subpanel. Is it allowed to have 8 15amp circuits assuming I don't plan to use all circuits to their capacity at the same time? (8*15a=120a, which is greater than the incoming 80a, does that pass inpsection)

This panel doesn't have a ground and i am planning to redo all circuits coming from it. I'm interested in what sort of changes I might do that would make changing the panel a requirement for passing inspection:

Can I add a circuit to this panel? I couldn't find circuit breakers like this anywhere I looked, what type are they?

If I replace the existing branches, they will require a ground wire correct? If this panel doesn't have one, does this mean I need to replace it with a panel that has one? Can I add a ground to this panell?

If I did add a ground, does it come from the main panel? Can/should this subpanel be grounded separately from the main?

Branches

Is there anything against running 2 branches in the same EMT run provided I meet the wire count limitations specified for a given EMT size?

I have an unfinished ceiling. Can I run branches to recepticles with electrical plugs mounted to the joists, and then plug shop lights into them (rather than hardwiring)? Where in the NEC I should look at for the rules that surround putting an electrical plug for lighting overhead?

 

[brewchief]

That's a pushmatic panel, breakers are available but I would simply replace it with a much more modern panel with more space.

There should only be one feed to the panel, it's possible that there are two single pole breakers feeding it.

Sent from my SM-G965U using Tapatalk

 

[pattenp]

All outlets need to be gfci protected, even ones that are on the ceiling for plug-in lights.
Is the feed to the garage coming from a two pole 40A breaker? It should be either a 4 wire or 3 wire feeder. Current code requires 4 wire, 2 hots, 1 neutral and 1 ground.

 

[Norcal]

The OP in in the Chicago area so that is pipe land, a metallic conduit is permitted to serve as the grounding conductor.

 

[wyliesdiesels]

Hi,

I have an existing detached garage, with wiring, but done poorly. I'm at the onset of planning, and i got great answers last time so I'm hoping someone will be gracious again. NEC 2014 is what I'm looking at for my area. I am looking at replacing all of the branches coming from this panel and will be having the work inspected.

Here's the subpanel I have. Power comes in through the bottom left, and leaves primarily out the top (with one exit on the lower right)

Panel Questions

I have 2 40a circuits from the main panel feeding this subpanel. Is it allowed to have 8 15amp circuits assuming I don't plan to use all circuits to their capacity at the same time? (8*15a=120a, which is greater than the incoming 80a, does that pass inpsection)

your picture link didnt work but i was able to copy and paste it

When you say 2 40a circuits, do you mean a 40a double pole breaker? thats not 2 40a circuits. thats 1 40a 240v circuit

As to the loading on the panel, adding up all the breakers means nothing because of load diversity. If you really wanna know if it will be ok, you need to do a load calc.

Now you havent listed your loads, number of people working, etc so theres really no way for us to ascertain what your load would be.

This panel doesn't have a ground and i am planning to redo all circuits coming from it. I'm interested in what sort of changes I might do that would make changing the panel a requirement for passing inspection:

IF the panel is fed with metallic conduit, that is your EGC as long as its intact end to end.

You also need 2 ground rods for detached structure. Do you have any?

Can I add a circuit to this panel? I couldn't find circuit breakers like this anywhere I looked, what type are they?

There is no more room in that panel for additional breakers and the panel is garbage. I would replace it.

If I replace the existing branches, they will require a ground wire correct? If this panel doesn't have one, does this mean I need to replace it with a panel that has one? Can I add a ground to this panel?

If I did add a ground, does it come from the main panel? Can/should this subpanel be grounded separately from the main?

Since youre in chicago, the metallic conduit provides the EGC/ground.

Do you have 2-wire or 3-wire outlets?

There is no ground bar or ground wires because the metallic conduits transfer the EGC through the panel enclosure.

As long as the conduit from the main panel is intact, you should be good with the grounds. make sure you have ground rods.

As to your questions in green. yes the ground wire would come from the main. As to grounding it separately, I'm not sure what you're referring to. Are you referring to ground rods? A detached panel needs both an EGC(metallic conduit in your situation) and 2 ground rods.

Branches

Is there anything against running 2 branches in the same EMT run provided I meet the wire count limitations specified for a given EMT size?

I have an unfinished ceiling. Can I run branches to receptacles with electrical plugs mounted to the joists, and then plug shop lights into them (rather than hardwiring)? Where in the NEC I should look at for the rules that surround putting an electrical plug for lighting overhead?

no

 

[jds62f]

All outlets need to be gfci protected, even ones that are on the ceiling for plug-in lights.
Is the feed to the garage coming from a two pole 40A breaker? It should be either a 4 wire or 3 wire feeder. Current code requires 4 wire, 2 hots, 1 neutral and 1 ground.

...

When you say 2 40a circuits, do you mean a 40a double pole breaker? thats not 2 40a circuits. thats 1 40a 240v circuit

The breaker on the main that goes to the garage looks like this, so I assume it is 240v/40a

...
As to the loading on the panel, adding up all the breakers means nothing because of load diversity. If you really wanna know if it will be ok, you need to do a load calc.

Now you havent listed your loads, number of people working, etc so theres really no way for us to ascertain what your load would be.

Thanks for confirming the load calculations drive the breaker and branch loads, not strictly the incoming values of the breakers feeding this panel. Understood that those breakers at the main do drive how much the subpanel can use at any given time.

...
You also need 2 ground rods for detached structure. Do you have any?

There are none that I can tell. more below.

...
Do you have 2-wire or 3-wire outlets?

I believe they are 2 wire. Often I do see a red, a black, and two white wires- a lot of the outlets are wired such that one of the 3 prong power outlets is always on, and the other is switched.

...
There is no ground bar or ground wires because the metallic conduits transfer the EGC through the panel enclosure.

As long as the conduit from the main panel is intact, you should be good with the grounds. make sure you have ground rods.

As to your questions in green. yes the ground wire would come from the main. As to grounding it separately, I'm not sure what you're referring to. Are you referring to ground rods? A detached panel needs both an EGC(metallic conduit in your situation) and 2 ground rods.

I'm learning so I think I've got some terms I am mixing. In newer panels I see a bar with the green wire and this panel doesn't have that. The conduit that brings power in does go into the ground, but there is a part of it rusted and it clearly needs replacement. There are no ground rods I see around my garage.... all I see coming out of the building are 2 pipes: One that I know has the blue, black, and white thick wires that go into this panel, and another pipe for natural gas (which I have turned off from the house).