Review on ⚡ Square QO120CAFI 20A Fault Breaker: Exceptional Performance for Enhanced Electrical Safety by Justin Guldin

The circuit breakers were housed in an SQ box and looked and worked like new. If you have an older SQ D, this is the only way to add arc fault protection and match the new code. They are longer than traditional switches and can fit well when there are a lot of thick gauge cables in the box. You will also need to remove the white neutral wire from the neutral terminal and reroute it to the arc breaker, then connect the white wire from the breaker to the box neutral terminal. You need to be sure you have the white wire that matches the hot wire on the switch. If you do not have electrical knowledge and experience, DO NOT attempt this.