Are people using #12 grounding pigtails when you pull #10's (on a 20A breaker)?

Status
Not open for further replies.

Finite10

Senior Member
Location
Great NW
250.122 (B) 2008 NEC Says it's not allowable to use those premade #12 grounding pigtails when you pull #10 ungrounded conduntors for voltage drop, or maybe just a job spec or whatever. Even though it's fused at 20A.
But- are people doing this?

One contractor bids to assemble Stakons and #10 green, but the next bids for premade #12 pigtails everywhere. Is this right?

What say you...
 

Finite10

Senior Member
Location
Great NW
2008 NEC 250.122(B) reads;
Increased in Size.
Where ungrounded conductors are increased in size, equipment grounding conductors, where installed, shall be indreased in size proportionately according to CM area of the ungrounded conductors.

It doesn't give a situation where you can reduce the size of the EGC to exposed metal surfaces. Not for Vd or spec. I guess not even if it's all you had in your van!
 

John120/240

Senior Member
Location
Olathe, Kansas
#10 AWG was used to compensate for voltage drop, correct ? Who in their right mind wants

to connect #10 AWG to a recptacle. Infinity & George have both stated the remedy.
 

Finite10

Senior Member
Location
Great NW
#10 AWG was used to compensate for voltage drop, correct ? Who in their right mind wants

to connect #10 AWG to a recptacle. Infinity & George have both stated the remedy.

Not allowed for Vd, for spec or for any reason.

While nobody, right or wrong mindedly, may WANT to - it reads as though they SHALL not reduce the EGC size below the circular mill area of the ungrounded conductors.


my .02
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
#10 AWG was used to compensate for voltage drop, correct ? Who in their right mind wants

to connect #10 AWG to a recptacle. Infinity & George have both stated the remedy.

I agree. If you increase the current carrying conductors from point A to B where ever that might be, then you only need to increase the grounding between the same points.
 

realolman

Senior Member
Not allowed for Vd, for spec or for any reason.

While nobody, right or wrong mindedly, may WANT to - it reads as though they SHALL not reduce the EGC size below the circular mill area of the ungrounded conductors.


my .02

You don't have to bring the ungrounded conductors that are oversized for VD the last six inches. .... #12 are suitable for 20 a. circuit
 

iwire

Moderator
Staff member
Location
Massachusetts
Not allowed for Vd, for spec or for any reason.

While nobody, right or wrong mindedly, may WANT to - it reads as though they SHALL not reduce the EGC size below the circular mill area of the ungrounded conductors.


my .02

Consider a large parking lot, like at any big box store.

We often run 4 AWG, sometimes 2 AWG circuit conductors on 20 or 30 amp circuits, but once we reach the poles we reduce down to 10 AWG go up the pole.

IMO the code as written in no way requires that we continue the 2 AWG EGC all the way up the pole to the heads.
 

Finite10

Senior Member
Location
Great NW
I agree. If you increase the current carrying conductors from point A to B where ever that might be, then you only need to increase the grounding between the same points.

Anybody have a citation that allows a reduction after table 250.122? I sure am open to learn of one. Seems explicitly stated to me.

The mudring, the green screw on a receptacle, or a lightpole - all are the end of the line for the EGC system. From ground bar to anywhere the user may encounter exposed non-current carrying metallic parts – no reduction in CM allowed, as written in 250.122(B), for any reason I can read.

Here's what I'm reading:

2008 NEC
"250.122(B);
Increased in Size.
Where ungrounded conductors are increased in size, equipment grounding conductors, where installed, shall be increased in size proportionately according to the circular mil area of the ungrounded conductors."
 
Last edited:

iwire

Moderator
Staff member
Location
Massachusetts
Anybody have a citation that allows a reduction after table 250.122? I sure am open to learn of one. Seems explicitly stated to me.


2008 NEC
"250.122(B);
Increased in Size.
Where ungrounded conductors are increased in size, equipment grounding conductors, where installed, shall be increased in size proportionately according to the circular mil area of the ungrounded conductors."

You seem to be missing 'where'.

Where they are increased in size so shall the EGC, where they are not increased in size that need not be.
 

Finite10

Senior Member
Location
Great NW
You don't have to bring the ungrounded conductors that are oversized for VD the last six inches. .... #12 are suitable for 20 a. circuit

LOL, I like the way you think. And I agree this needs an exception. But it does not mention anything about un-increasing the size for a bit. Once they've been increased in size... they've been increased in size. Can't pretend it didn't happen, unfortunately.:blink:

It doesn't say the increased size needs to be the entire length, just that they've been increased.
 

iwire

Moderator
Staff member
Location
Massachusetts
And if 'where' does not give you a warm fuzzy feeling there is this.

250.122 Size of Equipment Grounding Conductors.
(A) General.
Copper, aluminum, or copper-clad aluminum
equipment grounding conductors of the wire type shall not
be smaller than shown in Table 250.122, but in no case
shall they be required to be larger than the circuit conductors
supplying the equipment.
Where a cable tray, a raceway,
or a cable armor or sheath is used as the equipment
grounding conductor, as provided in 250.118 and
250.134(A), it shall comply with 250.4(A)(5) or (B)(4).
 

Finite10

Senior Member
Location
Great NW
You seem to be missing 'where'.

Where they are increased in size so shall the EGC, where they are not increased in size that need not be.

I think that may be a leap of semantics. The word 'where' in this context equates to 'in the case of' or 'in this instance'. Not 'where' as in 'place' or 'location'; 6" from where that bigger wire is located.
 

iwire

Moderator
Staff member
Location
Massachusetts
I think that may be a leap of semantics. The word 'where' in this context equates to 'in the case of' or 'in this instance'. Not 'where' as in 'place' or 'location'; 6" from where that bigger wire is located.

Can you point to anything to support your opinion?

In my opinion 'where' in this context is used as 'place or location'.

If they meant what you suggest in my opinion the word used would be 'when' not 'where'.

The support for my opinion comes from common senses. Electrically it would make no sense to require the EGC to be larger than the circuit conductors.

Further support for my opinion is the fact is that is how it is applied in the field by many.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Not allowed for Vd, for spec or for any reason.

While nobody, right or wrong mindedly, may WANT to - it reads as though they SHALL not reduce the EGC size below the circular mill area of the ungrounded conductors.


my .02
Answer this, do you think once you have increased the size of conductors to compensate for VD that size conductor has to remain through out the circuit?


Roger
 
Status
Not open for further replies.
Top