When you purchase and install FPE circuit breakers, the first thing you learn from reading a set of installation instructions is to make sure the power is completely off at the circuit breaker box. Turn the main circuit breaker to the off position and you kill power to the whole house. Are you ready to install your FPE circuit breaker safely at this stage?
Yes and no. Before you do the installation is is very important to use a volt meter to make absolutely certain there is no power coming to the electrical panel. Never assume that turning off the mains has actually stopped the flow of electricity until you can verify it with the volt meter. To properly install your FPE circuit breakers, you need to connect wires to the ground bus bar and the neutral bus bar. If any current is flowing, an electrocution hazard is present. The only way to tell is by using the volt meter.