- Occupation
- Licensed Electrician
I'm not gonna be Sancho Panza for you. You are on your own tilting at this windmill.
250.53(C) vs. 250.102(C)
- Thread starter George Stolz
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jwelectric
Senior Member
- Location
- North Carolina
- Location
- Illinois
- Occupation
- retired electrician
I don't really understand the question. 250.104(A)(1) says the jumper in question is sized per Table 250.66 and that table stops at 3/0.
Maybe I am on the wrong part of the water pipe, but if this is a metal underground water pipe used as a grounding electrode, I still see no need to have the connection larger than 3/0. I don't see it as a supply side bonding jumper, but I also don't see it defined in the code.
Maybe I am on the wrong part of the water pipe, but if this is a metal underground water pipe used as a grounding electrode, I still see no need to have the connection larger than 3/0. I don't see it as a supply side bonding jumper, but I also don't see it defined in the code.
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- Location
- Connecticut
- Occupation
- Engineer
Your conductor may meet the definition of an SSBJ, but that is irrelevant without a code section to support it.
You reference 250.102(C), but 250.102 is titled "Equipment Bonding Jumpers." The conductor between the steel and water main in your diagram is not an equipment bonding jumper per that definition.
SSBJ is also referenced in 250.30(A)(2) for Separately Derived Systems, but again, that code section doesn't apply to your diagram.
Your diagram does show two grounding electrodes which are required to be bonded together to for the grounding electrode system, per 250.50. As Mike Whitt tried to point out (with in error is his reference) 250.53(C) says that the bonding jumper used to connect the grounding electrodes together to form the grounding electrode system...shall be sized in accordance with 250.66.
That is the bonding jumper that is in your diagram. There is no need to size that jumper at 12.5% of the ungrounded conductors size, because it is not an equipment bonding jumper per 250.102.
If this is a truism................thank you for clarifying this.
If it's still up for interpretation, I will still call it a wire.
Thanks Dave
Is the conductor between the steel and the water pipe a Supply Side Bonding Jumper?
I think the answer to that is no. 250.102 is for "Equipment Bonding Jumpers". 250.102(C) is for equipment bonding jumpers on the supply side of the service. Look at the chapter 2 definition of "Bonding Jumper, Equipment". The conductor you are asking about isn't one of those, so I don't think 250.102 or its sub-section comes into play. This conductor is a bonding jumper used to connect the grounding electrodes together as covered in 250.53(C) and is sized per 250.66. Table 250.66 only goes up to 3/0.
If you look at the chapter 2 definition of "Bonding Jumper, Equipment", the bonding jumpers covered in 250.102(C) are intended to be able to carry fault current, whereas the bonding jumpers in the grounding electrode system do not have the primary function of carrying fault current. I think that is why 250.102(C) includes the language for increasing the size above 3/0 where needed, but 250.66 does not.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
Hi Ed!
"250.102(C) is for equipment bonding jumpers on the supply side of the service."
My 2011 doesn't say that. The term EBJ isn't in the whole section, skimming through.
Again, I think we all agree on the intent, but I think they stuffed the SSBJ into the NEC in a hurry and didn't notice the little things.
"250.102(C) is for equipment bonding jumpers on the supply side of the service."
My 2011 doesn't say that. The term EBJ isn't in the whole section, skimming through.
Again, I think we all agree on the intent, but I think they stuffed the SSBJ into the NEC in a hurry and didn't notice the little things.
jwelectric
Senior Member
- Location
- North Carolina
Thank you for the correction. I guess I need to start proof reading :ashamed1:
Ok, now I see more clearly what you're getting at. My first response was based on the 2008 NEC. The 2011 hasn't been adopted here yet, so I don't have a copy, but I just borrowed one and took a look. I agree with you, under the 2011 definitions, there is a good argument that 250.102(C) applies to the bonding jumpers in the grounding electrode system.
My answer would still be 3/0 for the conductor you're asking about and here's how I come to that conclusion. 250.102(C) is a general requirement for bonding jumpers on the supply side. 250.53(C) is specific to bonding jumpers in the grounding electrode system. Because it is more specific, it takes precedence over 250.102(C). But I think more work needs to be done to clarify this in the code.
I cannot agree...
1) 250.102(C) is in Part V. Bonding.
2) 250.90 through 250.100 are precursorial provisions to 250.102 and enumerate what equipment is to be bonded.
3) 250.102(C)(1) is titled: Size for Supply Conductors in a Single Raceway or Cable.
4) Taken in context with 250.102(C)(2) Size for Parallel Conductor Installations
, both 250.102(C)(1) & (C)(2) are regarding bonding conductors and jumpers run with supply conductors.
What I do agree with is the notion of specificity. I've always considered Part V Bonding as "fallback" grounding requirements for situations not covered specifically under the other parts of Article 250. Refer to Figure 250.1 Grounding and Bonding.
- Location
- Connecticut
- Occupation
- Engineer
2011 hasn't been adopted here either...so I just have a draft copy, not the final copy.
Isn't the title of section 250.102 still "Equipment Bonding Jumpers"????
If so then nothing in 250.102 would apply to bonding jumpers in the grounding electrode system.
No, the title has been changed to "Bonding Conductors and Jumpers", and the title of 250.102(C) has been changed to "Size - Supply-Side Bonding Jumper".
yankj
Senior Member
- Location
- Carrollton, Texas
This is a "grounding electrode conductor" and therefore according to table 260.66 it can be 3/0. You need not go any larger.
But there is no general provision under (C). Goes directly to (C)(1) which is titled, as I so noted earlier, "Size for Supply Conductors in a Single Raceway or Cable."
Oh, I'm not disagreeing with your position on this. Your argument makes sense. I was just answering david luchini's question.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
The conductor between the water pipe and steel is not a grounding electrode conductor, it is a binding jumper.
- Location
- Windsor, CO NEC: 2017
- Occupation
- Service Manager
That's pretty solid; but it could be better.
ha ha ha............
WIRE!
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I suppose it could be more redundant
- Occupation
- Licensed Electrician
I can live with that. One of the problems with art. 250 is the terminology. And they keep adding to it under the false belief that it makes things clearer.
Somebody needs to put some big sheets of paper up on a wall and divide it up into three columns-
Earth
Neutral/Grounded
Equipment Ground
Add two more sub columns-
Before the first disconnect and after the first disconnect.
Then give each type of connection or wire one name based on which column it falls in.
George, whatta ya think? You got it in youl?
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