EMT grounding question

[walaby]

I know I am asking a lot of questions regarding grounding. I have a ground mounted solar array. I am running my PV cables through the attic. I know I need to have the PV cables and metal conduit once it enters the attic. I am running a separate EGC from the solar panels through the conduit to ground within the inverter. I am not using the EMT as an EGC. Do I need to separately ground the EMT conduit. If so, can I ground within a junction box and run that ground wire to a ground in the inverter. Or do I actually have to ground both ends of this EMT run even though I am not using it as an EGC. The EMT will come from the attic into the garage and connect to a plastic housing for the PV disconnect. Out of the PV disconnect will be flexible non-metallic conduit to the inverter.

Thanks in advance for any responses

Mike

 

[Q-Dog]

Yes, the EMT needs to be bonded. You can use ground/bonding bushings inside the plastic junction box to bond the EMT. I used them on mine.

 

[walaby]

Ok. So in that case do I just bond at the end where the metal conduit enters the plastic junction box in the garage or do I have to bond at the other end where PVC and EMT connect? I forgot to add the fact that I am running the PV cables and the panel EGC through PVC up to the attic and then transitioning to EMT. That transition currently is a PVC female and EMT male threaded connection.

 

[Q-Dog]

Ok. So in that case do I just bond at the end where the metal conduit enters the plastic junction box in the garage or do I have to bond at the other end where PVC and EMT connect? I forgot to add the fact that I am running the PV cables and the panel EGC through PVC up to the attic and then transitioning to EMT. That transition currently is a PVC female and EMT male threaded connection.

If the EMT is continuous you only need to bond one end. If you have multiple separate runs, each run needs to be bonded. The idea is to give a path to earth if something shorts inside the EMT. Everything metal needs to be bonded.

 

[sumpower]

You can use a bonding bushing with a lay in lug to bond the EMT at the connector at a plastic junction box.

https://www.platt.com/p/0169854/3-4-insulated-grounding-bushing-lay-in-lug/018997004512/34dcigbu

 

[ricardocello]

If the EMT is continuous you only need to bond one end. If you have multiple separate runs, each run needs to be bonded. The idea is to give a path to earth if something shorts inside the EMT. Everything metal needs to be bonded.

totally correct

However, I don’t trust EMT to function as an EGC.
I always run a green ground wire through the EMT.
It does not count as a current carrying conductor for conduit derating (but does take up space).

 

[Q-Dog]

totally correct

However, I don’t trust EMT to function as an EGC.
I always run a green ground wire through the EMT.
It does not count as a current carrying conductor for conduit derating (but does take up space).

Just to clarify, I'm not saying to use the EMT as EGC.

 

[ricardocello]

Just to clarify, I'm not saying to use the EMT as EGC.

sorry, I didn’t mean to imply you were.

 

[walaby]

Thanks all

To clarify - I am NOT using EMT as an EGC.

The EMT is continuous across attic and down to the IMO PV disconnect.

Mike