- Location
- Massachusetts
don_resqcapt19 said:
Yes I knew about that.
It is not relevant to the point I was trying to make.
Derived Systems
- Thread starter mike0w
- Start date
- Status
Yes I knew about that.
It is not relevant to the point I was trying to make.
- Location
- Massachusetts
LarryFine said:
No, not to me.
We are not talking about a main bonding jumper, we are talking about an equipment bonding jumper.
It is not an EGC.
It is not an EGC until you are on the load side of the OCPD.
Check out this NECH image.
Exhibit 250.13 A grounding arrangement for a separately derived system in which the grounding electrode conductor connection is made at the transformer.
Notice what they call the conductor bonding the two separate enclosures.
It is not an EGC.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
It's funny Bob, but my 2005 Handbook has the exact same illustration with one exception. The words Bonding jumper are replaced with System bonding jumper. Seems that this was a change from the wording of 250.30(A)(1) from the 2002 NEC to the 2005.
- Location
- Massachusetts
infinity said:
So what your saying is,
Bob stop being cheap get a 2005 NECH.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
iwire said:So what your saying is,
Bob stop being cheap get a 2005 NECH.
I'm the cheapo. Couldn't get myself to pay a 150 or so bucks for the $1 CD-ROM.
- Location
- Illinois
- Occupation
- retired electrician
Bob,
Don
Maybe not, but you specified PVC between the panel and the transformer and that can put the exception into play depending on the mounting methods and building structure.
Don
- Location
- Massachusetts
I hear you Don, but help me out here.
Lets forget the PVC and say I used RMC.
Can I use the RMC as the systems bonding jumper as Larry was pointing out?
Obviously I do not think so.
Lets forget the PVC and say I used RMC.
Can I use the RMC as the systems bonding jumper as Larry was pointing out?
Obviously I do not think so.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Bob
I am not too sure if there is some confusion between the System Bonding Jumper 250.30(A)(1), and Equipment Bonding jumper 250.30(A)(2).
Both are sized using the same method.
Why could one not use the metallic raceway between the transformer and the first disconnect as the bonding jumper?
250.30(A)(2)
Where a bonding jumper of the WIRE type is run....
This portion of the requirement leads me to believe that it can be other than a conductor (wire).
I am not too sure if there is some confusion between the System Bonding Jumper 250.30(A)(1), and Equipment Bonding jumper 250.30(A)(2).
Both are sized using the same method.
Why could one not use the metallic raceway between the transformer and the first disconnect as the bonding jumper?
250.30(A)(2)
Where a bonding jumper of the WIRE type is run....
This portion of the requirement leads me to believe that it can be other than a conductor (wire).
- Location
- Illinois
- Occupation
- retired electrician
Bob,
Don
I agree that the conduit cannot be used as a system bonding jumper, but I don't see how it would ever be anything other than an EGC. If you place the system bonding jumper in the transformer the raceway to the panel is the EGC for the panel and its circuits. If you place the system bonding jumper in the panel, the raceway is the EGC for the transformer.
Don
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Yeah. What he said.
Whats interesting, in the 2005 CD hand book,(exhibit 250.13 and 250.7)These jumpers and grounds are applied differently.
Where the grounding electrode conductor connection is made at the xfrmr, the ground wire is called a system bonding jumper, but where the same connection is made at a generator, it is called an equipment grounding conductor.
Rick
Where the grounding electrode conductor connection is made at the xfrmr, the ground wire is called a system bonding jumper, but where the same connection is made at a generator, it is called an equipment grounding conductor.
Rick
- Location
- Massachusetts
don_resqcapt19 said:
Don that is odd to me.
Lets say we bond at the transformer and run a coper conductor to the first disconect beyond the transformer to bond the two enclosures together.
You say that conductor is an EGC.
How would you determine the correct size conductor?
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Bob
250.30(A)(2)
250.30(A)(2)
- Location
- Massachusetts
Pierre C Belarge said:
That is for GECs not EGCs or bonding jumpers.
I think you might have meant 250.30(A)(5)?
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Bob
Go back to your post with the illustration. They mislabeled the bonding jumper in the tranformer, or that is the 02 version... that conductor is now called the system bonding conductor.
Take a look at the bonding conductor installed from the transformer to the 1st disconnect. That is the bonding jumper that I am talking about, and it is sized according to 250.102(C), which says to use Table 250.66.
Go back to your post with the illustration. They mislabeled the bonding jumper in the tranformer, or that is the 02 version... that conductor is now called the system bonding conductor.
Take a look at the bonding conductor installed from the transformer to the 1st disconnect. That is the bonding jumper that I am talking about, and it is sized according to 250.102(C), which says to use Table 250.66.
- Location
- Massachusetts
It is the 2002 version but either way it is not identified as an EGC as Don and Larry are calling it.
I agree it would be sized per 250.66.
That alone should signal that it is not an EGC.
I agree it would be sized per 250.66.
That alone should signal that it is not an EGC.
- Location
- Illinois
- Occupation
- retired electrician
Bob,
Don
You are correct that it is an equipment bonding conductor, but there is no code requirement that it be a wire. If it is a wire it is sized by 250.66.
Don
- Status