Neutral wires at main service disconnect

[Joshua L. Frederick]

Newer SD 200 amp main service panel. Most of the grounded & grounding conductors were installed appropriately on the bus bars. However there were two isolated (bonded to panel) bus bars on both sides, with a few grounded & grounding conductors installed there. Now, I know the grounds are o.k. here, but what about the neutral wires and/or grounded conductors? Do the neutral wires need to be installed at the main neutral bus bar(s)?

Thanks in advance.

[Larry D. Kage]

Originally Posted by jfrederick

Newer SD 200 amp main service panel. Most of the grounded & grounding conductors were installed appropriately on the bus bars. However there were two isolated (bonded to panel) bus bars on both sides, with a few grounded & grounding conductors installed there. Now, I know the grounds are o.k. here, but what about the neutral wires and/or grounded conductors? Do the neutral wires need to be installed at the main neutral bus bar(s)?

Thanks in advance.

The grounded and grounding wires should be bonded at the service disconnect anyway...

[Robert Meier]

Those neutrals conductors are not permitted on the EGC bus even in a service panel as shown in that photo. I see a main breaker, is this the service disconnect?

200.2 General.
(B) Continuity. The continuity of a grounded conductor shall not depend on a connection to a metallic enclosure, raceway, or cable armor.

[Joshua L. Frederick]

Thanks Robert, just wanted to confirm.

[Jim Port]

Originally Posted by lkage

The grounded and grounding wires should be bonded at the service disconnect anyway...

The problem is that you now have return current on the metallic enclosure where you should not. RM has posted the code prohibition below.

[Larry D. Kage]

Originally Posted by Jim Port

The problem is that you now have return current on the metallic enclosure where you should not. RM has posted the code prohibition below.

Please help me out. Isn't that a bonding screw at the bottom of the grounded conductor bus bar?

[Jim Port]

That is a lug for a larger conductor. The bond screw on that Square D panel is out of the pic. It is a green domed head screw near the main breaker.

As it is now the neutral current will flow across the enclosure to the bond screw and then through the neutral buss and then out to the transformer.

[Larry D. Kage]

Originally Posted by Jim Port

As it is now the neutral current will flow across the enclosure to the bond screw and then through the neutral buss and then out to the transformer.

Thanks for the help.

[ROBERT V. YOUNG]

Originally Posted by Jim Port

That is a lug for a larger conductor. The bond screw on that Square D panel is out of the pic. It is a green domed head screw near the main breaker.

As it is now the neutral current will flow across the enclosure to the bond screw and then through the neutral buss and then out to the transformer.

Alwaysa green doomed or green screw that is sized to fit only that thread on the panel. Will not fit any other entry.
Am I correct in my statement Jim.

[Jim Port]

The domed screw is just for the Square D. The correct location is shown on the panel label.

IIRC Cutler-Hammer Classic uses a bond strap into the buss.