The heart of all ASCO transfer switches is the solenoid operator, unique in the transfer switch industry. Time and again, it provides repeatable, fast, true double-throw operation.
The operator has a proven track record for simplicity, dependability and easy maintainability because it has no motors, gears or complicated mechanisms.
Its design ensures that loads will never be unintentionally transferred to a dead or inadequate source as the solenoid is powered from the source to which the load is being transferred. The positive interlocking design helps keep the main contacts closed dur- ing short circuit conditions. The true, double throw design ensures crucial loads are not connected to both power sources at the same time.
Importantly, the solenoid is never fused as some operators are. Fusing can render the transfer switch inoperable, an obviously undesirable feature for use in emergency and legally required standby systems.
ASCO designed and commercialized the first solenoid operated transfer switch.