shielding terminal blocks and wiring from dust

Operating on a standard 24V control circuit

Always check for continuity across the relay terminals

ensuring a precision seal between the heat exchanger and the collector box

McDonnell & Miller 305200 Replacement Switch Els PW 17895 shielding terminal blocks and wiringThe McDonnell & Miller 305200 Replacement Switch (Model number FS4 33) is a high performance SPDT (Single Pole, Double Throw) snap action assembly specifically engineered for integration with general purpose liquid flow switches. This technician grade component serves as the core electrical interface for Series FS4 3 and FS4 3T units, detecting flow velocity changes to trigger or terminate power to downstream equipment such as pumps, burners, and