Equipotential bonding conductor in conduit

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infinity

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If the #8 solid copper EBC is run in a ferrous conduit (EMT) is bonding to the conduit ends required like with a GEC?
 

Carultch

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If the #8 solid copper EBC is run in a ferrous conduit (EMT) is bonding to the conduit ends required like with a GEC?

Only if there is no other way to achieve sufficient continuity among the equipment, the conduit, and the enclosures. For instance, plastic enclosure to plastic enclosure.

As long as at least one end of the conduit is sufficiently bonded to the equipment grounding conductor system, the conduit is as bonded as it needs to be.
 

infinity

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They serve two different purposes, so I say no.

That was my thought as well because of the purpose of the EBC. In this case the pool equipment room is next to the pool and the metallic parts requiring bonding are spread out around the room so they do not want the #8 run in free air around the room.
 

don_resqcapt19

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If the #8 solid copper EBC is run in a ferrous conduit (EMT) is bonding to the conduit ends required like with a GEC?
The code rule that requires the bonding only applies to GECs, it does not apply to this application, but the physics of the issue is the same in both cases. I would bond it as required for a GEC.

That being said, and given that the choke effect is limited at lower currents...currents below a few hundred amps...it probably doesn't make any real difference, as it is extremely unlikely that the bonding conductor would ever see such high currents.
 
The code rule that requires the bonding only applies to GECs, it does not apply to this application, but the physics of the issue is the same in both cases. I would bond it as required for a GEC.

That being said, and given that the choke effect is limited at lower currents...currents below a few hundred amps...it probably doesn't make any real difference, as it is extremely unlikely that the bonding conductor would ever see such high currents.

Ferrous metal conduit enclosed GEC has the choke effect due to the high frequency high current of lightning. In this application, the AC current in this solid conductor is not the same as high frequecy lightning current (high current lightning is a fast step-respond waveform and a step waveform is made up from many high frequency sinusoidal waveforms). GEC practice should not be required in this case.

Btw, GEC required to be installed in a straight line as possible due to a sharp bend angle would impede the high frequency current flow. This is not the case for general electrical practices.
 

iwire

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Btw, GEC required to be installed in a straight line as possible due to a sharp bend angle would impede the high frequency current flow.

Forgive me Brain but you are sounding like someone that spends all their time in a book and has no experience in the real world.

I will bring you on my next GEC job and you can show me how to route a GEC from equipment to ground rod with no sharp bends.

By the way, it may well be good idea but it is not required nor possible in most cases.
 
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Carultch

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Forgive me Brain but you are sounding like someone that spends all their time in a book and has no experience in the real world.

I will bring you on my next GEC job and you can show me how to route a GEC from equipment to ground rod with no sharp bends.

By the way, it may well be good idea but it is not required nor possible in most cases.


Did you intentionally misspell Brian as Brain? ;)

I agree. It is impractical to avoid bends completely, and often there simply isn't an option to install a perfectly straight and short GEC.
 
"As possible" or as good as it could be done. I meant don't give someone a reason to say it was a messy job, including the AHJ. I take ESD (electrostatic discharge) protection seriously in my microprocessor circuit designs, and I see lightning is just a much bigger bigger ESD event. The practice is the same: diverting the energy away by using low impedance conductor with small inductance as possible: short and straight. Consider grounding the neutral conductor from the meter panel 5' high, to a grounding electrode at soil level and 5' to the left. A nice looking GEC running from the meter straight down, 90* left turn to the electrode, is not as effective as compare to running the GEC diagonal straight from meter to electrode, for conducting lightning current. In modern-day fast digital circuit, capacitors with 1/8" long radial leads are useless for power filter, due to high inductance from the leads at high frequency. Only surface-mounted capacitors (have no leads) are used for fast response in delivering the instantaneous current demand.
 

GoldDigger

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It is sometimes difficult to give the necessary weight to the fact that a lightning strike is for many purposes better characterized as a very high frequency event than as a DC event.
 

don_resqcapt19

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"As possible" or as good as it could be done. I meant don't give someone a reason to say it was a messy job, including the AHJ. I take ESD (electrostatic discharge) protection seriously in my microprocessor circuit designs, and I see lightning is just a much bigger bigger ESD event. The practice is the same: diverting the energy away by using low impedance conductor with small inductance as possible: short and straight. Consider grounding the neutral conductor from the meter panel 5' high, to a grounding electrode at soil level and 5' to the left. A nice looking GEC running from the meter straight down, 90* left turn to the electrode, is not as effective as compare to running the GEC diagonal straight from meter to electrode, for conducting lightning current. In modern-day fast digital circuit, capacitors with 1/8" long radial leads are useless for power filter, due to high inductance from the leads at high frequency. Only surface-mounted capacitors (have no leads) are used for fast response in delivering the instantaneous current demand.
A contractor did that install would never get paid by me, and if one of my guys did it, he would no longer be one of my guys.
You work on the other side of the decimal point:)....micro or nano amps are likely a problem for you, but building electrical systems can take hundreds, maybe even thousands, of amps for a very short time without a problem.
 

don_resqcapt19

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Ferrous metal conduit enclosed GEC has the choke effect due to the high frequency high current of lightning. In this application, the AC current in this solid conductor is not the same as high frequecy lightning current (high current lightning is a fast step-respond waveform and a step waveform is made up from many high frequency sinusoidal waveforms). GEC practice should not be required in this case.

Btw, GEC required to be installed in a straight line as possible due to a sharp bend angle would impede the high frequency current flow. This is not the case for general electrical practices.
While the effect is not near as much with 60 hertz systems than it is with much higher frequencies, the impedance of a single conductor run in an unbonded ferrous raceway is about two times the impedance run in the open or in a non-ferrous raceway.
 
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