PCO-818 is engineered to provide complete sync system reliability in a compact, easy to use, and economical package. Its advanced modular design provides a level of flexibility never before available in an Automatic Changeover unit. When combined with its sync generator companion, the SPG-812, the PCO-818 can offer the best performance and reliability available today. The basic function of the unit is to monitor an installations primary sync generator and automatically switch to a backup generator in the event of a failure to the primary. Its modular design offers several advantages over traditional automatic changeover units. In addition, it is designed such that AC mains failure will not erase the memory of its last generator selection. Dual-coil latching relays provide a reliable signal path even if power is lost to the PCO-818. Meanwhile, its power supply features a universal voltage input range of 85Vac to 260Vac. In extreme conditions, it would be the last unit to shut down in the event of an AC mains failure.