grounding

[DCFIT]

while running EMT between service devices, meter, disconnects ect. do I need a grounding bushing at both ends of my conduit? was under the impression that there to be placed at all connection locations in devices. Cali code and Nevada are different Im currently working out of Las Vegas.

 

[infinity]

According to the NEC, a metallic service raceway (one that contains service entrance conductors) only requires bonding at one end. If there are no concentric or eccentric KO's present then you could use a method other than a bonding bushing.

 

[GoldDigger]

But note that this is very much dependent on the location of the ground neutral bond.
If the raceway contains wire EGC (or serves as the EGC?), then the condition of only carrying service conductors is not satisfied.

 

[iwire]

But note that this is very much dependent on the location of the ground neutral bond.
If the raceway contains wire EGC (or serves as the EGC?), then the condition of only carrying service conductors is not satisfied.

If there is an EGC it is not a service raceway.

 

[don_resqcapt19]

Also check with your utility...ours requires grounding bushings on both ends of a metallic raceway between the meter and the service equipment.

 

[al hildenbrand]

while running EMT between service devices, meter, disconnects ect. do I need a grounding bushing at both ends of my conduit?

According to the NEC, a metallic service raceway (one that contains service entrance conductors) only requires bonding at one end. If there are no concentric or eccentric KO's present then you could use a method other than a bonding bushing.

On the line side of the Disconnect, the Service Conductors are protected only by the overcurrent device(s) of the Power Company (PoCo) supply transformer. If a energized service conductor faults to the EMT it is in, the fault current must get large enough to trip that PoCo transformer overcurrent device, so we, as installing electricians, must establish the Effective Ground-Fault Current Path (see Article 100 Definition). The primary (although not only) current path is back through the grounded service conductor, so the single bond to grounded service conductor on one end of the run of EMT is all that is needed.

And, on the LOAD side of the Service Disconnect, the discussion of the bonding is different as it is now the Equipment Grounding Conductor.

 

[al hildenbrand]

Also check with your utility...ours requires grounding bushings on both ends of a metallic raceway between the meter and the service equipment.

Interesting.

I've never experienced a PoCo making such a requirement for the 208 or 240 Volt service conductive raceways. Is it only one PoCo? You probably have worked with several? Yes?

 

[don_resqcapt19]

Interesting.

I've never experienced a PoCo making such a requirement for the 208 or 240 Volt service conductive raceways. Is it only one PoCo? You probably have worked with several? Yes?

It was Illinois Power, but there have been an number mergers and now it is Ameren. I just looked at their latest rules and they now say grounding as required by the NEC.

 

[al hildenbrand]

It was Illinois Power, but there have been an number mergers and now it is Ameren. I just looked at their latest rules and they now say grounding as required by the NEC.

Thanks Don. Illinois Power is another example of how diverse the local PoCo rules can be.

 

[don_resqcapt19]

Thanks Don. Illinois Power is another example of how diverse the local PoCo rules can be.

Yes, our city had to fight with them to accept the concrete encased electrode. They were insisting that even with the concrete encased electrode that the contractor had to provide two driven rods. After some discussions they agreed to hook-up any service that had our city inspector's approved tag on it.

 

[al hildenbrand]

After some discussions they agreed to hook-up any service that had our city inspector's approved tag on it.

[laughing] [/laughing]