32 A adjustable overload — sets the motor FLA window
The MS450-32 is a 3-phase Manual Motor Protector (MMP) rated 32 A, with an adjustable overload range of 22 to 32 A Full Load Amps (FLA). That adjustment band is where you set the motor's actual running current — the device trips when the load exceeds that set point over time, protecting the winding from sustained overload. Trip Class is listed as 10/20, meaning the overload relay can be set to either a Class 10 or Class 20 trip curve. Class 10 trips faster (within 10 seconds at 600% of set current) — better for submersible pumps or compressors that must clear a stalled rotor quickly. Class 20 gives more time for high-inertia loads like fans or centrifuges to accelerate without nuisance tripping.
Integrated short-circuit and phase-failure protection
This MMP includes built-in short-circuit protection and phase-failure detection per the description. That means it combines the motor disconnect, overload relay, and magnetic short-circuit trip in one device — no separate fuse or circuit breaker needed upstream for the motor branch circuit, as long as the SCCR rating of the panel is met. Rated 600 V, UL508 listed — the standard for industrial control equipment in North America. The UL508 listing covers the device as a manual motor controller and protector, which is the basis for accepting it in a UL 508A panel.
Active production — no successor on record
Sourced through independent distribution channels.