Siemens QG320 20-Amp Three Pole Switching Neutral BreakerSwitching neutral breakers are used when all conductors are required to be disconnected. There is an additional pole connected to each switching neutral breaker that provides a means of disconnecting the neutral when the breaker is tripped or open. The additional pole does not connect to and is not energized by the bus bar. Siemens strongly recommends against the use of "used" breakers. The installation of used breakers in a Siemens panel will void