Mars mars-33245 Thermal Time Delay Relay Sequencer

Product Description

The MARS mars-33245 is a thermal time delay relay sequencer designed for staged electrical control in HVAC systems. It provides an ON delay range of 30 to 75 seconds and an OFF delay range of 1 to 40 seconds, making it well suited for sequencing electric heat strips, blower motors, or other loads that require controlled startup and shutdown timing. The contact configuration is DPST normally open. Licensed HVAC technicians and service professionals install this type of component as part of electric furnace or air handler sequencing circuits to prevent simultaneous load energization and protect system components from current surges.

This sequencer is used in residential and light commercial electric heating applications where staged heat element activation is required. It is commonly installed inside electric furnaces and air handlers to stagger the energization of resistance heat strips. Proper sequencing reduces demand spikes and extends the service life of contactors, fuses, and heating elements. This part is suited for retrofit and replacement work in systems that require a thermally actuated two-pole normally open relay with adjustable delay timing.

Key Features

• ON delay adjustable from 30 to 75 seconds for staged load activation
• OFF delay adjustable from 1 to 40 seconds for controlled load deenergization
• DPST normally open contact configuration provides two switched poles
• Thermal actuation mechanism — no electronic components to fail in high-heat environments
• Compact design suitable for installation inside electric furnace control compartments

Compatibility

Designed as an OEM-style replacement thermal time delay relay sequencer for residential and light commercial electric furnaces and air handlers requiring DPST normally open contact sequencing with adjustable ON and OFF delay timing.

Installation Notes

Installation should be performed by a licensed HVAC technician. Disconnect and lock out all electrical power to the unit before removing the existing sequencer or making any wiring connections. Follow applicable NEC requirements for low-voltage and line-voltage wiring within the air handler or furnace cabinet. Verify delay timing settings are appropriate for the load being sequenced before returning the system to service.

Technical Specifications

• ON Delay Range: 30 to 75 seconds
• OFF Delay Range: 1 to 40 seconds
• Contact Configuration: DPST Normally Open
• Relay Type: Thermal Time Delay
• UNSPSC Code: 39121604

Standard Information

• Brand: MARS
• Manufacturer Part Number: mars-33245