No ground wire

[wwhitney]

ferrous raceways

I should have said ferrous wiring methods. For example, it would apply to steel jacketed MC cable, but not aluminum jacketed MC cable.

Cheers, Wayne

 

[infinity]

It bears repeating that the 300.3(B) graphic only applies to ferrous raceways, as 300.3(B)(3) would allow the EGC outside the raceway or cable for nonferrous wiring methods. The graphic could use updating to reflect that.

Wayne can you clarify how this is applicable to the OP? 300.3(B)(3) references 300.20(B) which makes no mention of any installation that resembles running 600' of EGC on the outside of a PVC raceway. Is there some other applicable section that would allow this?

2020 NEC:

300.3(B)(3) Nonferrous Wiring Methods.
Conductors in wiring methods with a nonmetallic or other nonmagnetic sheath, where run in different raceways, auxiliary gutters, cable trays, trenches, cables, or cords, shall comply with 300.20(B).

300.20(B) Individual Conductors.
Where a single conductor carrying alternating current passes through metal with magnetic properties, the inductive effect shall be minimized by (1) cutting slots in the metal between the individual holes through which the individual conductors pass or (2) passing all the conductors in the circuit through an insulating wall sufficiently large for all of the conductors of the circuit.

 

[ptonsparky]

Digging up and strapping an external EG to 600' of conduit is not practical even if legal.
Would not even consider it. Someone else could have the project. With my blessings.

 

[wwhitney]

Wayne can you clarify how this is applicable to the OP? 300.3(B)(3) references 300.20(B) which makes no mention of any installation that resembles running 600' of EGC on the outside of a PVC raceway. Is there some other applicable section that would allow this?

Sure. The wording at the start of 300.3(B) prohibits the EGC from being outside the conduit, except for the situations covered in subsections (1) through (4).

The title of subsection (3) tells you all nonferrous wiring methods are exempt from 300.3(B), as long as you comply with the requitements within section (3). The first sentence expands the requirements of 300.20(B) from covering just "single conductors" (per the text of 300.20(B)) to any time you fail to comply with 300.3(B) (e.g. two different cables with nonferrous sheaths carrying the circuit conductors, but no "single conductors".) So strap your EGC to the outside of your PVC conduit as long as you comply with 300.20(B) at the ends.

Of course, and perhaps this was your point, your EGC still needs to be in a Chapter 3 wiring method, barring one of the retrofit allowances in Article 250. [That also applies to the graphic Dennis posted.] That's why I think someone suggested single conductor UF cable for the EGC. Or you could pull an EGC in a separate small PVC conduit next to your main conduit.

Cheers, Wayne

 

[don_resqcapt19]

Wayne can you clarify how this is applicable to the OP? 300.3(B)(3) references 300.20(B) which makes no mention of any installation that resembles running 600' of EGC on the outside of a PVC raceway. Is there some other applicable section that would allow this?

2020 NEC:

I agree that 300.3(B)(3) is an exception and permits the ECG or any other conductor of a circuit to be run separate from other circuit conductors as long as there is no ferrous coverings. I doubt that was the intent, but that is what the language says.

 

[kwired]

Sure. The wording at the start of 300.3(B) prohibits the EGC from being outside the conduit, except for the situations covered in subsections (1) through (4).

The title of subsection (3) tells you all nonferrous wiring methods are exempt from 300.3(B), as long as you comply with the requitements within section (3). The first sentence expands the requirements of 300.20(B) from covering just "single conductors" (per the text of 300.20(B)) to any time you fail to comply with 300.3(B) (e.g. two different cables with nonferrous sheaths carrying the circuit conductors, but no "single conductors".) So strap your EGC to the outside of your PVC conduit as long as you comply with 300.20(B) at the ends.

Of course, and perhaps this was your point, your EGC still needs to be in a Chapter 3 wiring method, barring one of the retrofit allowances in Article 250. [That also applies to the graphic Dennis posted.] That's why I think someone suggested single conductor UF cable for the EGC. Or you could pull an EGC in a separate small PVC conduit next to your main conduit.

Cheers, Wayne

But then an EGC can be bare conductor in most cases as well so does it really matter what is or if there is any covering on the conductor except in the few cases that do require a covering?

 

[wwhitney]

But then an EGC can be bare conductor in most cases as well so does it really matter what is or if there is any covering on the conductor except in the few cases that do require a covering?

I was going to say that an EGC still needs to be part of a Chapter 3 wiring method. In fact (2017) 300.3(A) says "Single conductors specified in Table
310.104(A) shall only be installed where part of a recognized wiring method of Chapter 3."

Chapter 310.104(A) covers insulation types, so 300.3(A) would apply to an insulated EGC. But that still leaves your question, what about a bare EGC? Is there any code section that would prohibit, for a non-ferrous wiring method, running a bare EGC strapped to the outside of the cable or raceway that contains the circuit conductors?

Article 250 has some provisions limiting the length of bonding jumpers, and the definitional distinction between a bonding jumper and an EGC is poor, but let's assume that this is not a bonding jumper so such limits don't apply.

Seems like 300.3(A) needs an exception for GECs, bonding jumpers, etc that may be insulated and may be run outside of a Chapter 3 wiring method.

Cheers, Wayne

 

[kwired]

I was going to say that an EGC still needs to be part of a Chapter 3 wiring method. In fact (2017) 300.3(A) says "Single conductors specified in Table
310.104(A) shall only be installed where part of a recognized wiring method of Chapter 3."

Chapter 310.104(A) covers insulation types, so 300.3(A) would apply to an insulated EGC. But that still leaves your question, what about a bare EGC? Is there any code section that would prohibit, for a non-ferrous wiring method, running a bare EGC strapped to the outside of the cable or raceway that contains the circuit conductors?

Article 250 has some provisions limiting the length of bonding jumpers, and the definitional distinction between a bonding jumper and an EGC is poor, but let's assume that this is not a bonding jumper so such limits don't apply.

Seems like 300.3(A) needs an exception for GECs, bonding jumpers, etc that may be insulated and may be run outside of a Chapter 3 wiring method.

Cheers, Wayne

Something I run into occasionally is direct bury underground to field irrigation equipment that was 480 V corner grounded delta when it was new, most were back in 1970's and 80's. They were often up to 1400' runs from utility pole to the equipment and POCO was installing them at that time. Three conductors direct buried, no problem. Then sometime in late 80' and early 90's POCO's decided corner ground delta was too dangerous for the many non qualified farmers that often ended up messing with this equipment and occasionally electrocuting themselves. So they started converting to 480/277 wye systems and burying a fourth conductor that was to be the grounded conductor. Problem is they would mark out where existing conductors were and would trench that grounded conductor in anywhere between 5 and 10 feet away for most of the length of the run. Always wondered how much impedance that introduced in ground fault situations.

 

[ptonsparky]

Something I run into occasionally is direct bury underground to field irrigation equipment that was 480 V corner grounded delta when it was new, most were back in 1970's and 80's. They were often up to 1400' runs from utility pole to the equipment and POCO was installing them at that time. Three conductors direct buried, no problem. Then sometime in late 80' and early 90's POCO's decided corner ground delta was too dangerous for the many non qualified farmers that often ended up messing with this equipment and occasionally electrocuting themselves. So they started converting to 480/277 wye systems and burying a fourth conductor that was to be the grounded conductor. Problem is they would mark out where existing conductors were and would trench that grounded conductor in anywhere between 5 and 10 feet away for most of the length of the run. Always wondered how much impedance that introduced in ground fault situations.

Did that once way back when and always wondered.

 

[Jpflex]

If this were a metallic emt or rmc pipe and were not underground NEC says you would not have to run a ground/ bonding wire inside or outside of conduit if you make metallic conduit mechanically tight along with bonding bushings and wire to

 

[kwired]

If this were a metallic emt or rmc pipe and were not underground NEC says you would not have to run a ground/ bonding wire inside or outside of conduit if you make metallic conduit mechanically tight along with bonding bushings and wire to

Correct, but there is times when a metal raceway needs bonding jumper around it because it is not sufficient enough of an EGC. Mostly with metallic flex or places where electrical continuity is not well maintained for whatever reason.

 

[infinity]

If this were a metallic emt or rmc pipe and were not underground NEC says you would not have to run a ground/ bonding wire inside or outside of conduit if you make metallic conduit mechanically tight along with bonding bushings and wire to

What does underground have to do with it being an EGC?

 

[Buck Parrish]

This is not optional. Metallic well casings must be connected to the EGC. See 250.112(M). There have been deaths over the years due to unbonded well casings. All modern well casing caps have provision for this.

Yes , I know you know. But for the benifit of those that don't.
They make little plastic brackets to keep the wire from hitting the sides. If it hits the sides , every time the pump kicks on it sometimes bumps the wire. Then obviously it will ware a bare spot on the wire causing problems.

 

[ptonsparky]

Yes , I know you know. But for the benifit of those that don't.
They make little plastic brackets to keep the wire from hitting the sides. If it hits the sides , every time the pump kicks on it sometimes bumps the wire. Then obviously it will ware a bare spot on the wire causing problems.
View attachment 2562030

Every well guy in my area uses tape. At least for the small ones I see.

 

[LarryFine]

If this were a metallic emt or rmc pipe and were not underground NEC says you would not have to run a ground/ bonding wire inside or outside of conduit if you make metallic conduit mechanically tight along with bonding bushings and wire to

Metal conduit underground doesn't last forever. That's the one application I install an EGC in metal for, even RMC.

 

[kwired]

Metal conduit underground doesn't last forever. That's the one application I install an EGC in metal for, even RMC.

depends on soil conditions but often it is the first few inches above and below grade that corrode the fastest