Does my main service panel need grounded?

[Strathead]

We are on the same page I believe.

Take a GE main service panel for instance. The grounded conductors and EGCs are landed on the neutral buses (the buses and strap make up the neutral bus assembly as you pointed out)

So if someone asked me "why do you need to install the bonding screw? The grounds and neutrals are already connected"

My answer would be...

I'm installing the screw to bond the enclosure to the neutral that way a fault will clear if an ungrounded conductor ever contacted the enclosure and also if at a later date someone added circuits and ran out of room on the neutral bus they could install an EGC bus, move some EGCs over to it and those EGCs are bonded to the neutral by the screw.

Did I miss anything?

I feel that it is important to point out terminology, especially at the service disconnect. So I would say, grounded bus, and bonded to the grounded conductor. Part of my reasoning is that in all other enclosures you do a similar thing and even green help generally gets this information quickly. That is bonding all metal parts together to the "grounding conductor" Often referred to as grounding the enclosure. At the service disconnect is where the grounding conductor and the grounded conductor diverge. So that additional level of ensuring that the enclosure is bonded to the grounded conductor needs to be ensured.

 

[DBoone]

Correct you are bonding the enclosure. The bonding jumper is just the starting point for the entire equipment grounding conductor network. Any enclosure ahead of the bonding jumper (primarily dealing with services here) is bonded to the grounded conductor and there is no EGC. At the service equipment they are basically the same thing - except the grounded conductor can not rely on the enclosure as part of it's current path, but the equipment grounding conductor can.

:thumbsup:

 

[DBoone]

I feel that it is important to point out terminology, especially at the service disconnect. So I would say, grounded bus, and bonded to the grounded conductor. Part of my reasoning is that in all other enclosures you do a similar thing and even green help generally gets this information quickly. That is bonding all metal parts together to the "grounding conductor" Often referred to as grounding the enclosure. At the service disconnect is where the grounding conductor and the grounded conductor diverge. So that additional level of ensuring that the enclosure is bonded to the grounded conductor needs to be ensured.

:thumbsup:

BTW, I'm over to the west of you. Vacationing in Destin. Headed home today. Great weather.