Heat Controller DXM2 Electronic Heat Pump Controls, DXM2 UNIT CONTROLS, Heat Controller, Inc

Heat Controller, Inc. DXM2 UNIT CONTROLS Application, Operation, & Maintenance Manual

DXM2 Electronic Heat Pump Controls

DXM2 OVERVIEW

The manufacturer’s next generation control board, DXM2, is the geothermal industry’s first two-way communication.

The DXM2 electronic control is a robust, microprocessor based heat pump controller that is advanced and feature- laden for maximum application flexibility. The DXM2 Control has relay outputs for Compressor, Compressor Speed, Reversing Valve, Alarm Relay, and 2 configurable relays for Fan, Fan Speed, HWG Pump, and Loop Pump, and 2 configurable accessory relay outputs. For on board diagnostics, there are 2 LED’s to 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. Additional configurable temperature sensor inputs are available that may be used for hot water, compressor discharge, leaving air, leaving water, and entering water temperature sensors.

The DXM2 has an RS485 communications port to interface with a communicating thermostat or other compatible controls.

DXM2 Controller Part Number:

17B0002N02 DXM2 Control Board

General Operating Parameters

The following are general operating parameters for the DXM2 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.

Power Requirements

DXM2 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.

Relay and Connection Contact Ratings

The following relays are mounted on the DXM2 Control:

•Compressor Relay: 40VA at 24VAC

•Compressor Speed Relay: 28VA 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 / Loop Pump Relay: 1 HP at 240VAC

•Fan Speed / HWG Pump Relay: 1 HP at 240VAC

•Connection ratings on the DXM2 Control:

•‘A’ terminal: 20VA at 24VAC. Larger solenoid valve draw should be controlled with accessory relays.

Grounding

The control board must be grounded from one of the C terminals.

Basic Control Features

•Single or two–stage compressor control

•Anti-short cycle protection

•High pressure cut-out

•Loss of charge cut-out

•High and low voltage cut-outs

•Water coil low temperature cut-out

•Air coil low temperature cut-out

•Random start

•Status LED and Fault LED

•Reset lockout at unit or disconnect

•Condensate overflow sensor

•Intelligent fault retry

•Test Mode

•Multiple blower configuration options

•Electric heat outputs

•Accessory water valve connection

Advanced Control Features

•Direct control of ECM blower

•Intelligent hot water generator control

•Two accessory relays configurable for multiple applications

•Internal Flow Center output

•Proportional valve output

•Night setback with override capability

•Emergency shutdown capability

•Removable thermostat connector for ease of installation and service

•Accepts conventional heat pump (Y,O) or heat/cool (Y,W) thermostat types

•RS–485 port to interface with a communicating thermostat or other compatible controls

•Boilerless electric heat

•Configurable inputs and outputs for advanced functions

3