Siemens service panel neutral bonding???

[johnv]

I am installing a 100 amp subpanel off my Siemens 200 amp main entry panel. I do NOT see any jumpers bonding either neutral bar to the box. Neutral bars are bonded together. Are Siemens panels bonded differently??? the screw hole in the lug holding the main neutral wire is there, but NO green screw bonding it to the panel box??? Seems not right to me. Am not an electrician but work in electronics and I think I understand basic electicity. Anyone have experience with the Siemens panels?? This is a fairly new house, completed in Dec 2004, reputable builder, passed all inspections etc. Thanks in advance.

JohnV

[HayZee518]

Somewhere they have a bonding jumper affixed to the panel. You just loosen a screw and insert it in the neutral bar lug and tighten both the panel enclosure screw and neutral screw. In your case as a sub-panel do not bond the neutral to enclosure ground. What you must do is install an auxillary ground bar and tie all your earth grounds into this NOT the neutrals. The feeder from your main must contain 4 wires Hot-Hot-Neutral-Ground.

[johnv]

Zee,

Thanks for the reply. This panel has the service disconnect outside. Bonding is there, all seems righteous.

JohnV

[SSN596]

To be clear, there are specific codes governing neutrals and grounds in subpanels, and partly if depends on whether it is in an attached or detached structure.

The idea is, if you connect neutral and ground together, you could have half the neutral current flowing back to the main through the grounding wire. This is bad. Post back with your more specific descriptions of your layout.