# of wires through knockout

2 questions for an inspection I’m doing (see attached pictures)

  1. how many branch service circuits can go through one knockout? There are about 4 in this panel.

  2. When is it OK to have only 3 conductors (hot, hot, neutral) in a 120/240 main panel? This panel is on the inside wall while the meter is on the outside directly behind it. However, there is no ground conductor, and the ground and neutral bars aren’t bonded. The neutral bar has the green ground screw in it. Thoughts?




The question should have been how many cables are the connectors or clamps listed for. That depends on the device used and it’s listing. However, two xx-2 or one xx-3 cables in the correct sizes are typical.

You did not say there was a disconnect outside near the meter which makes this the service panel which only needs a 3 wire feed. There is no separate ground bar. The bars are bonded together by the insulated jumper shown just above the bond screw.

The panel enclosure is bonded to the service neutral via the green screw. A separate equipment grounding bus can be connected directly to the enclosure without the need for a separate bonding jumper. Your photo’s do not show the separate EGC bus but if it’s bolted to the enclosure then it’s code compliant.