Bizarre Workshop Wiring

goose134 · 11-07-2007, 06:16 PM

When you open up your sub panel there will be a green screw that bonds the neutral bus to the case. After you run the new feed and before you connect it, remove the screw. If you have a grounding detail in the panel, great. If not, get one. Pull a four wire circuit into your pipe (Two hots, nuetral and ground). Land your hots on the breaker, neutral on the bus, and the ground on the ground detail. By bonding the panel in the shed again, you will create a multiple ground. Very bad. As for the ground rods I don't think you'll need them (I may be wrong on this) But it's all about equipotential on the ground. You don't want multiple points of ground. Hope that was a bit clearer.

Andy in ATL · 11-07-2007, 06:26 PM

250.32 of the NEC says that yes... you got to have the rods. Go ahead and include them. Much more important is the previous advice. Ground and neutral seperate. Even though there are no metallic pathways now there may be in the future. OBJECTIONABLE CURRENT, while being certainly objectionable, also kills people under the right circumstances.

goose134 · 11-07-2007, 08:19 PM

I may be reading this wrong, but 250.32 (d) says to bond the ground of the outbuilding in the absence of a grounding electrode. I think that if he were to simply bond the ground in the outbuilding it should be compliant. Now if the sub panel does not have the disconnecting means, I believe you may be right about the rods. Am I reading this right? Go through conditions 1,2, and 3 in the section I referenced.

slakker · 11-07-2007, 09:28 PM

You guys are going to places that as a Canadian, I have no point of reference...

But it is still very interesting as the theory still holds...

goose134 · 11-08-2007, 11:23 PM

Never mind. I re read 250.32. You're right about the ground rods.

Andy in ATL · 11-09-2007, 03:49 PM

Rods are my favourite...not!!!! What is 110% more important than the rods is a PERFECTLY RIGHT AND TIGHT connection of everything back to the source. Read what Stubbie has to say on another thread today about subs. It explains it all.

11-07-2007, 06:16 PM	#16
goose134 Union Electrician Join Date: Nov 2007 Location: Chicago, USA Posts: 615	Bizarre Workshop Wiring When you open up your sub panel there will be a green screw that bonds the neutral bus to the case. After you run the new feed and before you connect it, remove the screw. If you have a grounding detail in the panel, great. If not, get one. Pull a four wire circuit into your pipe (Two hots, nuetral and ground). Land your hots on the breaker, neutral on the bus, and the ground on the ground detail. By bonding the panel in the shed again, you will create a multiple ground. Very bad. As for the ground rods I don't think you'll need them (I may be wrong on this) But it's all about equipotential on the ground. You don't want multiple points of ground. Hope that was a bit clearer.

11-07-2007, 06:26 PM	#17
Andy in ATL Electrician philosopher Join Date: Aug 2007 Location: Lilburn, GA Posts: 838	Bizarre Workshop Wiring 250.32 of the NEC says that yes... you got to have the rods. Go ahead and include them. Much more important is the previous advice. Ground and neutral seperate. Even though there are no metallic pathways now there may be in the future. OBJECTIONABLE CURRENT, while being certainly objectionable, also kills people under the right circumstances.

11-07-2007, 08:19 PM	#18
goose134 Union Electrician Join Date: Nov 2007 Location: Chicago, USA Posts: 615	Bizarre Workshop Wiring I may be reading this wrong, but 250.32 (d) says to bond the ground of the outbuilding in the absence of a grounding electrode. I think that if he were to simply bond the ground in the outbuilding it should be compliant. Now if the sub panel does not have the disconnecting means, I believe you may be right about the rods. Am I reading this right? Go through conditions 1,2, and 3 in the section I referenced.

11-07-2007, 09:28 PM	#19
slakker Member Join Date: May 2007 Posts: 220	Bizarre Workshop Wiring You guys are going to places that as a Canadian, I have no point of reference... But it is still very interesting as the theory still holds...

11-08-2007, 11:23 PM	#20
goose134 Union Electrician Join Date: Nov 2007 Location: Chicago, USA Posts: 615	Bizarre Workshop Wiring Never mind. I re read 250.32. You're right about the ground rods.

Bizarre Workshop Wiring