Mars mars-33232 Heat Sequencer 3 Switches 24V Control

Product Description

The MARS mars-33232 is a heat sequencer designed for electric furnace and air handler applications that require staged heating element control. It features one DPST switch and one SPST switch across three switch positions, delivering two independent timing circuits. The main switch operates on a 1 to 24 second on-delay and a 45 to 75 second off-delay, with the auxiliary switch sharing the same timing range. Control voltage is 24 volts, and the sequencer is rated for 25 FLA at 240 volts. Licensed HVAC technicians handling electric resistance heating equipment are the primary installers of this component.

This sequencer is used in residential and light commercial electric forced-air heating systems where sequential staging of heating elements is required to prevent nuisance tripping of circuit breakers and reduce demand spikes at startup. It is commonly found in electric furnaces and heat strips inside air handlers. The two-timing configuration allows the installer to stagger element energization across the heating cycle, providing smooth, staged heat output during both the on and off sequences.

Key Features

• One DPST and one SPST switch configuration across 3 switch positions
• Two independent timing circuits for staged element control
• Main and auxiliary switch on-time: 1 to 24 seconds
• Main and auxiliary switch off-time: 45 to 75 seconds
• Rated 25 FLA at 240 volts for electric resistance heating loads
• 24-volt control circuit compatible with standard low-voltage thermostat wiring

Compatibility

The MARS mars-33232 references cross-reference number 51172-32 and is designed as an OEM-style replacement sequencer for electric furnaces and heat strip assemblies that require a 1 DPST and 1 SPST configuration with 24-volt control voltage.

Installation Notes

Heat sequencers are installed by licensed HVAC technicians. Disconnect and lock out all power to the unit before removing or installing a sequencer, as the heating element circuits carry 240-volt line voltage. Verify that the replacement sequencer matches the switch configuration, timing range, and FLA rating of the original before energizing the system. Inspect bimetal contacts and wiring terminals for corrosion or heat damage during the replacement procedure.

Technical Specifications

• Switch Type: 1 DPST and 1 SPST
• Number of Switches: 3
• Number of Timings: 2
• Control Voltage: 24 volts
• FLA at 240V: 25 amps
• Main Switch On-Time: 1 to 24 seconds
• Main Switch Off-Time: 45 to 75 seconds
• Auxiliary Switch On-Time: 1 to 24 seconds
• Auxiliary Switch Off-Time: 45 to 75 seconds
• Weight: 4 pounds

Standard Information

• Brand: MARS
• Manufacturer Part Number: mars-33232