Mars 43906 Fan Cycling Pressure Control 210 275 Psi

Product Description

The MARS (MOTORS ARMATURES) 43906 is a fan cycling pressure control designed to regulate condenser fan operation in refrigeration and air conditioning systems. This control operates on a close-on-rise pressure action, with setpoints at 210 and 275 psi, making it suitable for head pressure control applications. It is typically installed by licensed HVAC-R technicians as part of condenser fan cycling schemes that protect compressor operation during low-ambient and variable-load conditions.

The 43906 is used in commercial and residential refrigeration and air conditioning condensing units where head pressure must be maintained within a defined operating range. Fan cycling controls of this type are commonly found in rooftop units, remote condensers, and split-system condensing sections. When head pressure drops below the cut-out point, the control opens the fan circuit; when pressure rises to the cut-in setpoint, the circuit closes and the condenser fan restarts.

Key Features

• Close-on-rise pressure action for condenser fan cycling duty
• Cut-in pressure setpoint of 210 psi
• Cut-out pressure setpoint of 275 psi
• Designed for head pressure control in refrigeration and AC condensing systems
• Supports low-ambient head pressure protection strategies

Compatibility

Designed as an OEM-style replacement fan cycling pressure control for refrigeration and air conditioning condensing units requiring a close-on-rise pressure switch in the 210 to 275 psi operating range.

Installation Notes

Installation should be performed by a licensed HVAC-R technician. Recover or isolate refrigerant pressure from the circuit before removing or installing any pressure control fitting. Verify the refrigerant type and system operating pressures are compatible with the control range before installation. Follow all applicable local codes and the system manufacturer guidelines when wiring the fan contactor circuit to this control.