Sub panel to a sub panel

I am building a detatched garage about 75 feet from my attached
garage. I have my main panel and a sub panel beside each other in my
attached garage. The sub panel only has my small upstairs heat pump/
air conditioner for a bonus room hooked to it as well as a 50 amp plug
for a small welder I almost never use. Can I run a sub panel in my new
detached garage/workshop from the sub panel in my current attached
garage?
If so, do I need another ground rod at the detached garage?
If it helps, I can remove the 50 amp welding plug because I only plan
to wel in the detached garage anyway.
I have 200 amp service in my main panel. I think the sub panel next to
it I bought was either a 50 or 100 amp panel but like I sais, the only
thing on it is the 1.5 ton heat pump. It is usually turned off as the
upstairs is a play room for the kids.
I added the sub panel because all of the breakers in my main pannel
were almost full.
Reply to
stryped
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Maybe. What type of cable (size, material, and number of conductors) runs from the main panel to the existing subpanel? What is the rating of the existing subpanel? Is the subpanel connected to a breaker in the main panel, and if so, what is the rating of that breaker?
Yes.
Do so.
That makes a BIG difference.
IMO you're much better off hiring a licensed electrician. The questions you're asking -- and the fact that you failed to gather such elementary but crucial information such as the rating of the existing subpanel -- strongly suggest that you do not possess the knowledge or the skills to do this safely on your own.
Reply to
Doug Miller
stryped fired this volley in news:2a8c8464-ab25- snipped-for-privacy@r36g2000vbn.googlegroups.com:
Someone could. We've watched your progress long enough to think that's not safe (for your family -- think "kids playing upstairs") for you to do.
Two, eight feet apart in many jurisdictions.
That scares me. It sound like you have multiple circuits stuffed into all the available connector space on every breaker.
An electrician might be your best friend, here.
I'm not banging on you, Stryped. This just doesn't sound like the right project for you to undertake.
LLoyd
Reply to
Lloyd E. Sponenburgh
The main pannel had two spots left. I added a 100 amp breaker in the main panel to the 100 amp sub panel. the wiring between the two was the correct size for 100 amps. (I checked when I did this several years ago.)
Reply to
stryped
Let's double-check, OK? Please answer all of these questions:
What type of wire? What gauge? How many conductors did you run to the subpanel? What are they connected to? Does the subpanel have separate busses for neutral and ground? Are they connected to each other, or electrically separate? How are the neutral and ground busses in the subpanel connected to the main panel?
Reply to
Doug Miller
snipped-for-privacy@milmac.com (Doug Miller) fired this volley in news:BxH6m.20458 $ snipped-for-privacy@nlpi070.nbdc.sbc.com:
And how far, Doug. (actual wire run, Stryped, not just the "walking distance".) LLoyd
Reply to
Lloyd E. Sponenburgh
The sub panel is essentially a main type panel. I will have to look again at the wire, but there is a 100 amp breaker form the main panel feeding the sub pannel. The sub panel has a 100 amp main breaker also.
Everythign feeds to the main panel. (ground and everything.)
I will take some pictures tonight.
Reply to
stryped
Make a hole in the main panel for another sub panel, just like you did before. Move a couple of circuits to the other sub if necessary. Yes you will need a main panel, ground rods and fused disconnect at the new shop. I'd leave the welding plug for possible future use. It only matters if you try to use it while heavily loaded on other circuits, but if everything is fused/breakered correctly you should still be safe.
Reply to
Tim
How did that truck engine overhaul work out?
Reply to
Jim Stewart
Great. I am sellign it as we speak. It runs like a scalded dog. (it is fairly fast). the only thing I have noticed is after sittign overnight when starting it there is some lifter ticking that goes away after about 5 seconds.
For what it is worth. I ask alot of questions here but all of my projects (knock on wood) have turned out ok, (That is why I ask alot of questions, to make sure everythign is right.).
The tiller is still runnign too by the way :)
Reply to
stryped
is there a reason to run the second sub from the main panel rather than the 1st sub panel?
Do I need a disconnect on top of having a panel in the attached garage with a main breaker? Where would I put it, on the outside of the building?
Reply to
stryped
-is there a reason to run the second sub from the main panel rather -than the 1st sub panel?
Yes, you want your load to come through the 200 amp main breaker if you have a 200 amp meter can and service. Connecting up stream or bypassing the 200 amp main could allow you to overload the service.
-Do I need a disconnect on top of having a panel in the attached garage -with a main breaker? Where would I put it, on the outside of the -building?
I'm not certain what the codes say, but a disconnect on the outside of your main service panel could be a good idea just before you go underground. When you come up to the new service, a fused disconnect shouldn't be necessary if you come through the wall, and immediately in to your new panel. If you cannot locate your new main panel, just inside the wall from your service entrance, then yes, a fused disconnect would be a must.
Reply to
Tim
What Lloyd said.
What Doug said.
FWIW: My shop uses the cheapest available (usu. on sale) 4 ft. fluorescent fixtures, mounted 2 each over major machine tools. Additional spot lighting on each machine tool is turned on as needed.
Recommend you get the services of a licensed electrician for bulk of electrical specks and design, even if you do the work yourself. This may prevent grief from the electrical inspector. In the same regard, be sure to obtain a building permit as required in your area.
Bob Swinney
Reply to
Robert Swinney
What size panel for the new garage would I need? (If my home service is 200 amps, and my current sub panel is 100 amps?) Can I put another 100 amp panel in my new garage/shop?
I will have to route the cable under the house (crawl space) and outside under a deck to a ditch to the new shop. So you are sayign a disconnect where the wite comes out of the house? (Which would be under the deck).
B the way, I will have to disconnect somethignin the main panel to give me space for the extra sub panel. If there is not enough slack to move it over. (wire wise). What can I do?
Reply to
stryped
If you installed it the same way as a main panel is installed, then you installed it wrong.
And is the subpanel rated for 100A?
That's fine, but make sure to answer the questions too -- we won't be able to tell wire type or gauge from photographs.
Reply to
Doug Miller
???
The 1st subpanel is fed from the main; if he feeds the second subpanel from the first, he's still feeding from the main anyway. There's no danger of overloading the service.
And *assuming* that the breaker protecting the feed from the main to the first subpanel is properly sized for the conductors, there's no danger of overloading that feed either.
Reply to
Doug Miller
What can you do? Hire an electrician. Please. You're in over your head. The safety of your family is at stake.
Reply to
Doug Miller
What do you mean if I installed it the same as the main panel it is wrong? I put a (rated) 100 am sub panel right next to the main panel. There is a 100 amp breaker in the main panel feeding the sub panel and also a 100 amp main breaker in the sub panel. the ground in the sub runs to the grounding bus in the main panel.
Reply to
stryped
Code requires the main and neutral bus bars to be bonded together in the main panel, and requires them to be electrically *isolated* in subpanels.
Reply to
Doug Miller
Do you mean ground and neutral?
i
Reply to
Ignoramus20849

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