Benshaw SPO-85-55A Relay

The Benshaw SPO-85-55A is a three-pole, bimetallic Class 10 overload relay designed to protect motors in 3-phase circuits and mount directly to Benshaw RSC contactors (RSC-50, RSC-65, RSC-75, and RSC-85) in any coil voltage. It provides thermal overload protection with a trip range of 45–65 A, guarding against motor damage from overloads, phase failure, and long starting times or stalling in AC-3 service. The device includes a pair of auxiliary contacts—a normally open and a normally closed contact—for signaling and for interrupting the coil to shut the starter down when protection is activated. As part of the RMSO/SPO family, the SPO-85-55A delivers reliable, mechanical overload protection with straightforward integration into standard low-voltage motor-control schemes and works with Benshaw control products to maintain consistent protection across the drive system.