The DXM electronic control is a robust, microprocessor based heat pump controller that is advanced and feature-laden for maximum application flexibility. The DXM Control has all of the basic CXM control features plus additional inputs and outputs which allow for extensive system capability. The DXM Control has relay outputs for Compressor, Fan, Fan Speed, Reversing V alve, Alarm Relay, and 2 configurable accessory outputs. There are 3 LED’s which provide status indication.

There are inputs for safety pressure switches, low temperature protection thermistors, condensate overflow sensor, DIP switch selection inputs, thermostat inputs, night setback inputs, and emergency shutdown input. There are also 2 communications ports: one for communications with DXM dual compressor heat pumps, and another for communications with DXM slaved heat pumps.

DXM Controller Part Number
17B0002N01 DXM Control Board

General Operating Parameters
The following are general operating parameters for the DXM Control:

• Operating Environment: -40°F to 176°F and up to 95% relative humidity, non-condensing.
• Storage Environment: -40°F to 185°F and up to 95% relative humidity, non-condensing.

DXM Power Requirements

• DXM only power draw –
• Normally 8 VA draw at 24VAC
• Maximum 12 VA draw at 24VAC. A dedicated 24VAC, 50-60Hz, 1Ph, 40VA transformer minimum is required for typical WSHP application.

DXM Relay and Connection Contact Ratings
The following relays are mounted on the DXM Control:

• Compressor Relay: 40VA at 24VAC
• Alarm Relay: 28VA at 24VAC
• Reversing Valve: 28VA at 24VAC
• Accessory Relay 1: 28VA at 24VAC
• Accessory Relay 2: 28VA at 24VAC
• Fan Enable Relay: 1 HP at 240VAC
• Fan Speed Relay: 1 HP at 240VAC
• Connection ratings on the DXM Control:
• ‘A’ terminal: 20VA at 24VAC. Larger solenoid valve draw should be used with accessory relays.

DXM Grounding
The control board is grounded through two of the metal standoffs.

Basic DXM Control Features

• Anti-short cycle protection
• High and low pressure cutouts
• High and low voltage cutouts
• Water coil low temperature cut-out
• Air coil low temperature cut-out
• Random start
• Status LED, test LED, and fault LED
• Reset lockout at unit or disconnect
• Intelligent reset
• Condensate overflow sensor
• Test Mode
• Electric heat outputs
• Accessory water valve connection

Advanced Control Features

• Two accessory relays configurable for multiple applications
• Night setback with override capability
• Emergency shutdown capability
• Communications port for DXM dual compressor applications
• Communications port for DXM slave heat pump applications
• Intelligent fan speed capabilities
• Boilerless electric heat
• Removable thermostat connector for ease of installation and service
• Accepts heat pump (Y,O) or heat/cool (Y,W) thermostat types
• Accepts heat pump thermostats with O or B reversing valve control logic
• Dehumidistat input for advanced functions