MARS 33246 Sequencer

The MARS 33246 Sequencer is a field-proven DPST electric heat sequencer engineered for multi-stage staging in electric furnaces, heat pumps, and air handlers. This 2-switch thermal time delay relay utilizes a solid-state PTC (Positive Temperature Coefficient) heater to provide reliable, voltage-compensated timing, ensuring consistent performance even during line voltage fluctuations. With a 24V control circuit, it manages the sequential activation of heating elements and blower motors to prevent excessive inrush current and nuisance tripping of circuit breakers.

Designed as a versatile cross-reference replacement for Honeywell, White-Rodgers, and Klixon 60000EOM-158 controls, the 33246 is non-positional, allowing for flexible mounting in tight electrical cabinets. It features standard double quick-connect terminals for straightforward wiring of combination fan and element systems. The snap-action internal mechanism is shock and vibration resistant, providing positive make/break action across an ambient temperature range of -40°F to 165°F. For complex staging, multiple units can be wired in series to control additional heater banks while maintaining integrated fan interlock safety via the M1-M2 terminals.

• Reduced Inrush Current: Staggered timing prevents simultaneous element activation, protecting electrical service components.
• Broad Compatibility: Serves as a direct HVAC sequencer replacement for most major OEM furnace and heat pump brands.
• Positive Snap-Action: High-grade bimetal discs ensure clean contact transitions to prevent arcing and premature wear.
• Flexible Mounting: Non-positional design ensures reliable operation regardless of orientation within the air handler.
• Environmental Resilience: PTC heater technology compensates for ambient temperature shifts to maintain accurate timing logic.

What are the specific timing sequences for this model?
The MARS 33246 provides an ON delay of 1-60 seconds for both switches and an OFF delay of 1-45 seconds, ensuring the blower stays energized until elements have sufficiently cooled.

Can I use the 33246 to replace a single-switch sequencer?
Yes, this DPST sequencer can replace SPST models by utilizing only one set of contacts, provided the electrical ratings (25A at 240V) meet or exceed the original part specifications.

How do I wire this for a fan interlock?
The M1-M2 terminals should always be assigned to the blower circuit to ensure the fan is the first component on and the last component off during the heating cycle.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.