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I just installed a sub panel in my garage 50 amp. i removed the strap that ties the ground and neutral bus bars.I know a 76 year old retired electrician I asked him to check my work. He told me that they should be connected. The Garage is detached from the house.Everything i read says no. Now i am confused. i put the trap back but after he left i shut the breaker in the house till i figure this out.He is old a nice guy i didnt argue. i do think his mind is slipping a little.Once and for all how should a sub panel in a detached garage be ?? thank you !
Reply:A sub panel should have a separate ground and neutral. If you have them bonded the ground will carry power that should be going through the neutral wire. This is dangerous because it will cause everything that is grounded to be hot.ZachLast edited by WTXBTUMOVER; 06-01-2016 at 08:20 PM.
Reply:Remove the bonding strap.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:What did you take from the house to supply the garage? Assuming that you took 240V from the house did you take 2 hot legs, a neutral and a ground, or just 2 hot legs and a neutral? If you brought the ground from the house you need an isolated neutral bar. If you didn't bring the ground you can reestablish the ground neutral bond and you will need to drive some ground rods and bond the water service if you have one in the garage. Please note that this is only legal because of the garage is detached. Also your local code may have other inclusions or deletions from the NEC and may not be using the current code at all. Bottom line is I have no idea what your local government requires but I can tell you what the current NEC says on the subject. Good luck with your project.
Reply:Originally Posted by gundog77What did you take from the house to supply the garage? Assuming that you took 240V from the house did you take 2 hot legs, a neutral and a ground, or just 2 hot legs and a neutral? If you brought the ground from the house you need an isolated neutral bar. If you didn't bring the ground you can reestablish the ground neutral bond and you will need to drive some ground rods and bond the water service if you have one in the garage. Please note that this is only legal because of the garage is detached. Also your local code may have other inclusions or deletions from the NEC and may not be using the current code at all. Bottom line is I have no idea what your local government requires but I can tell you what the current NEC says on the subject. Good luck with your project.
Reply:Originally Posted by winginitThe sub panel in the detached garage is supplied with 6/3ga
Reply:What they said. Each service gets one point where ground, and white center tap connect. Usually this takes place in the enclosure where the service disconnect(s) are. No other place are they to be bonded. Driven rods are correct. Connect them to bare ground conductor, and buss bar. The white conductor floats on a plastic insulated buss. This does NOT connect to ground except in the enclosure for service disconnect. Had it been twenty five years ago, there would be one conductor run for neutral, and ground. You would bond then.WillieThere is no such thing as neutral. The white wire connects to the middle of your utility transformer. Half the time it is the source of electrons. DO NOT TREAT IT AS GROUND!!!!! IT IS LIVE!!!! Think of it as a hot leg as you do the other two. It is!Last edited by Willie B; 06-01-2016 at 09:28 PM.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Originally Posted by AcemanYou can't run Romex outdoors to a detached garage. You need a wet location wire or cable.
Reply:Originally Posted by Willie BWhat they said. Each service gets one point where ground, and white center tap connect. Usually this takes place in the enclosure where the service disconnect(s) are. No other place are they to be bonded. Driven rods are correct. Connect them to bare ground conductor, and buss bar. The white conductor floats on a plastic insulated buss. This does NOT connect to ground except in the enclosure for service disconnect. Willie
Reply:I have one other question that was not asked. How far are you running from main panel to sub panel?Klutch 220si mig , stick, and dc tigHobart 140 AHP ALPHA 200X 2016Lotos LTP5000DSmith O/P
Reply:Sub panel wiring is quite simple but many people get it wrong, including some that are working as "electricians". The grounding conductors must always be isolated from the grounded conductors (usually incorrectly called neutral conductors) after the first disconnect. A common mistake is to run only 3 conductors for a 240 sub panel and drive grounding rods for the grounding conductors. This leaves you with no ground fault protection and in the event of a ground fault it energizes the grounding system without tripping a breaker.Miller Challenger 172Miller Thunderbolt AC/DC 225/150Miller Maxstar 150 STLVictor 100CVictor JourneymanOxweld OAHarris O/ASmith O/A little torchNo, that's not my car.
Reply:you are correct in "NOT" bonding the neutral in your sub panel. the grounds you added are a bonus + to your installation. As for the real reason you should not bond the neutral in the sub. " In the even of of failure of the neutral in your sub panel the "ground" usually undersised from the neutral would be forced to carry the return current back to the main panel.
Reply:I thought detached garages (buildings) were treated differently than true sub panels within the same structure."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:Originally Posted by SandyI thought detached garages (buildings) were treated differently than true sub panels within the same structure.
Reply:Originally Posted by bigbThey were some years back. But there were still conditions, mainly that a detached structure could be supplied with a 3 wire feeder only if there were no other conductive paths (metal piping, phone line etc). Existing 3 wire installations are still allowed as long as there are no other conductive paths and the neutral must be bonded. Per current NEC all new installations require 4 wires (unless 120 volts only) and a supplementary grounding electrode system at the detached structure
Reply:Originally Posted by bigbThey were some years back. But there were still conditions, mainly that a detached structure could be supplied with a 3 wire feeder only if there were no other conductive paths (metal piping, phone line etc). Existing 3 wire installations are still allowed as long as there are no other conductive paths and the neutral must be bonded................... Per current NEC all new installations require 4 wires (unless 120 volts only) and a supplementary grounding electrode system at the detached structure
Reply:Originally Posted by bigbSub panel wiring is quite simple but many people get it wrong, including some that are working as "electricians". The grounding conductors must always be isolated from the grounded conductors (usually incorrectly called neutral conductors) after the first disconnect. A common mistake is to run only 3 conductors for a 240 sub panel and drive grounding rods for the grounding conductors. This leaves you with no ground fault protection and in the event of a ground fault it energizes the grounding system without tripping a breaker.
Reply:Originally Posted by SandyAnd what happens with the neutral? Bonded or through?
Reply:Originally Posted by bigbThey were some years back. But there were still conditions, mainly that a detached structure could be supplied with a 3 wire feeder only if there were no other conductive paths (metal piping, phone line etc). Existing 3 wire installations are still allowed as long as there are no other conductive paths and the neutral must be bonded. Per current NEC all new installations require 4 wires (unless 120 volts only) and a supplementary grounding electrode system at the detached structure
Reply:Ill bet that replacing the panel is the same as a new installation in the eyes of the electrical inspector and he's going to insist on 4 wires. I needed to have one piece of my feeder line replaced and wasn't allowed to repair it, it all had to be brought up to current code (built in 1952). Building department required new feeders from the street, new meter pan, new panel, every bit of wire up to the panel.In the end l am glad they made me do it the right way because it allowed me to upgrade to 200 amp service and get rid of a fuse box with a sub breaker panel.As to the o.p. when my garage sub panel was installed, the tie bar to the ground neutral was left in place and a seperate ground bus bar was installed in the panel isolated from the originals, building department wanted it that way so that's what we did.apparently it makes it obvious to anyone that looks that the ground and neutral are seperated.Last edited by Sedanman; 06-02-2016 at 11:13 AM.Eventual master of the obvious, practitioner of "stream of consciousness fabrication". P.S. I edit almost every post because because I'm posting from my phone and my fingers sometimes move faster than my brain.
Reply:Originally Posted by SedanmanIll bet that replacing the panel is the same as a new installation in the eyes of the electrical inspector and he's going to insist on 4 wires. I needed to have one piece of my feeder line replaced and wasn't allowed to repair it, it all had to be brought up to current code (built in 1952). Building department required new feeders from the street, new meter pan, new panel, every bit of wire up to the panel.In the end l am glad they made me do it the right way because it allowed me to upgrade to 200 amp service and get rid of a fuse box with a sub breaker panel.As to the o.p. when my garage sub panel was installed, the tie bar to the ground neutral was left in place and a seperate ground bus bar was installed in the panel isolated from the originals, building department wanted it that way so that's what we did.apparently it makes it obvious to anyone that looks that the ground and neutral are seperated.
Reply:Originally Posted by winginitThanks i removed the bonding strap this morning and installed a 110v outlet circit with 1 outside plug. i am going to post another question about installing 50amp outlet box on the outside of my garage. Thanks
Reply:Only certain voltage, and amperage need GFCI protection. Home depot online offers a covered rain tight enclosure for RV power. It comes with a receptacle you can replace with the needed one. The enclosure is made by Midwestern, model # eludes me at the moment. the Leviton # for the receptacle is 5374.Enter through the bottom using 6-3 SEU, or UF-B, and a 842 Arlington connector. Use Noalox from Ideal on the wires. A disconnect turning it off when not in use is a good plan. I use Square D QO 200TR disconnects if I can't turn off the circuit breaker. WillieAn optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared. |
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发表于 2021-8-31 22:05:14