What to do When the Panel Neutral Bar is Full

By - Summary:

How to Expand the Capacity of the Neutral Terminal Bar in a Panel: If the terminal bar runs out of room then an additional terminal bar may be added.

Expanding the Capacity of the Neutral Terminal Bar in a Panel

Electrical Question: I would like info on adding an additional neutral bar to my main service panel.

  • I have a Cutler Hammer CH20CM100 panel with a 100 amp main breaker.
  • I switched out the single breakers for tandems to get additional circuits however I ran out of space on the existing neutral bar with only 13 holes.
  • I am adding a GBK21CS bar for extra spaces.
  • I am using a #6 jumper wire from the original bar to the new one.
    • My question is, does the new bar have to be isolated from the panel box or can I just use supplied self tapping screws and mount it directly to the box?
      • The original bar is mounted in a plastic housing which I assume isolates it from the box.
      • The main feed is 3 wire with 2 hot legs to the main breaker and an aluminum wire to the neutral.
      • There is also a bare ground wire from the neutral bar to the water pipes.

This electrical wiring question came from: Richard, a Contractor from Keyport, New Jersey.
See more about Home Wiring for New Jersey

Dave’s Reply:
Thanks for your electrical wiring question Richard.

How to Expand the Capacity of the Neutral Terminal Bar in a Panel

  • Both the Grounds and Neutrals are bonded together in the Main Electrical Panel.
  • If the terminal bar runs out of room then an additional terminal bar may be added.
  • Typically the additional terminal bar is  available from the panel manufacturer and is designed for mounting to pre-drilled and tapped holes of the panel enclosure.

Please Note:
Home Owners or inexperienced individuals should not perform work in electrical panels, but rather locate a licensed electrical contractor to perform this type of panel work and wiring.

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