The Series PCP Level Controller is designed to be a power supply, an external relay, and a latching relay for differential level control with two level switches. As a power supply the PCP can step down line voltage to 5 or 24 VDC to power NPN switches such as the OLS and PC level switches or to power a transmitter. The PCP can function as an external relay to increase switching capability by providing up to a 10A SPDT contact for direct control of moderate loads. As a latching relay the PCP can be used with any two normally open level switches and provide level control for pumps. The latching circuit can also be used to hold the relay in an actuated state until manually reset.