Garage Subpanel - Do I understand this right?

[BMS]

Couple pics of the subpanel in my garage. I think I understand this correctly but just wanted to verify. The subpanel doesn't have a separate ground bar so neutral and ground are both terminated on the same bar. Per NEC, the subpanel should have a separate ground bar. This could have been done 30 years ago so may be it was different then or maybe the homeowner did it all himself.

The second part that had me scratching my head for a min is the green and white wires (ground and neutral) that are twisted together. I am assuming that was done just to save space since there is no separate ground bar in the subpanel. Is that what it looks like to you all? Each one of those green/white twisted pair feeds one outlet around the garage.

I'm looking to remove a couple of the single 10amp outlets and connect a 20amp dedicated circuit for a mini-split a/c I just installed (110v unit). Went into the panel and wanted to make sure I understood what the previous owner had done before I started moving stuff around. Would like to bring it up to code while I am in there if that means adding a dedicated ground bar.

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[pattenp]

You've got it right. The grounds need to be isolated from the neutrals, so you need to add a ground bar and remove the ground bonding screw from the existing bar to the panel.

To clarify, is this an attached garage? If detached garage then there could be other problems.

Edit: The conduit for the all the circuits looks like it may be suffering from over fill.

 

[oleguy]

grounds and neutrals need to be in seperate screws.

 

[xbanone]

To clarify, is this an attached garage? If detached garage then there are other problems.

If it is detached, can you elaborate on this for educational purposes?

 

[pattenp]

If detached it's considered an outbuilding so,

1) It needs to have its own grounding electrode system, which I can't see that it has.

2) There needs to be a main disconnect since there are more than six (6) breakers to turn off the power at the garage. I don't see one of those either.

If it is detached, can you elaborate on this for educational purposes?

 

[BMS]

It is an attached garage. Thanks for the feedback. Yes, I plan on combining some of the circuits since for the outlets, each outlet is on one breaker.

 

[Gooch]

You've got it right. The grounds need to be isolated from the neutrals, so you need to add a ground bar and remove the ground bonding screw from the existing bar to the panel.

To clarify, is this an attached garage? If detached garage then there could be other problems.

Edit: The conduit for the all the circuits looks like it may be suffering from over fill.

DO NOT do this UNLESS you add a seperate ground wire (4 wires) from the main panel!!!!!

 

[brewchief]

DO NOT do this UNLESS you add a separate ground wire (4 wires) from the main panel!!!!!

I see 4 wires there, 5 if you count how they split the ground into two separate sections so they would fit the lugs.

 

[Gooch]

I see 4 wires there, 5 if you count how they split the ground into two separate sections so they would fit the lugs.

Hard to tell where it exactly goes since it is not bundled in with the rest of the conductors in the SE cable used.

 

[Alchymist]

Hard to tell from the picture, but it looks like no anti-oxidant paste was used on the aluminum terminations.

 

[pattenp]

Looks like 3 w/g SER to me. The OP will need to say for sure.

Edit: Looking closer at the picture it almost looks like that heavy wire hooked to the neutral bar is a separate pull outside of the SE cable.

DO NOT do this UNLESS you add a seperate ground wire (4 wires) from the main panel!!!!!

 

[brewchief]

Hard to tell where it exactly goes since it is not bundled in with the rest of the conductors in the SE cable used.

Good eye, it looked to me like it was part of the SER cable but on closer inspection it looks like it's separate. I wonder if it goes back to the panel or to a ground rod or what?


In a subpanel in an attached garage was it ever code to only have 3 wires plus a ground rod like it was in a detached garage? If so what code cycle was it?

 

[BMS]

you guys are right. that separate black wire goes outside to a ground rod.

 

[Alchymist]

Good eye, it looked to me like it was part of the SER cable but on closer inspection it looks like it's separate. I wonder if it goes back to the panel or to a ground rod or what?


In a subpanel in an attached garage was it ever code to only have 3 wires plus a ground rod like it was in a detached garage? If so what code cycle was it?

Only reference handy is the 1999 issue, and even then 4 wire was called out, section 250-32. HOWEVER, Fig. 250.13 gives one exception - If a building is supplied by only 1 branch circuit, a ground electrode is not required.

 

[ElectroLight]

So, the cable feeding the garage from the house main panel lacks a neutral. This is an attached building so the panel should be feed with a 4 conductor cable that has the two hots, one neutral and one ground. The ground and neutral are to remain separate (separate busses, no bonding screw as mentioned earlier). Go to the house panel, pull the cover and snap a pic, I wonder where that ground braid landed?
Hate to say it, but this is looking like a DIY hack job.

 

[pattenp]

That being the case then forget what I said about isolating the neutral and grounds. You need an insulated neutral back to the main panel before you can separate the neutral and grounds.
You need to pull the correct 4 wire SER cable. If the feed was wired correctly you would not need the ********* wire to a ground rod.

you guys are right. that separate black wire goes outside to a ground rod.