John asks us: One of my junior electricians lost the green bonding screw in an electrical cabinet we are installing. Can I use a regular silver machine screw to replace it?
Thank you for your question regarding green bonding screws, it is our pleasure to help.
No. You may not replace the green bonding screw with a silver one. NEC Article 250.28 (B) clearly states that the bonding screw (either the Main Bonding Jumper and/or the System Bonding Jumper) must be green in color and that it must be visible when installed.
Remember that the Main Bonding Jumper and System Bonding Jumper perform the same engineering function, in that they are the two (2) and only two (2) mandatory neutral-to-earth bonds that must occur in your electrical system. The Main Bonding Jumper is the name for the bond that occurs inside the transformer, the System Bonding Jumper is the name for the bond that must occur in the first service disconnect. See NEC 250.28. In your case, you are talking about the System Bonding Jumper which must be a visible green screw.
Sorry for the bad news, but your going to have to run to the shop and grab a few green screws! Good luck!
The Engineering Team at E&S Earthing Solutions