Heat Controller, Inc. | DXM2 UNIT CONTROLS | Application, Operation, & Maintenance Manual |
Advanced Troubleshooting and Configuration Information
General
To properly configure and troubleshoot advanced control features, and to aid in troubleshooting basic control features, a communicating thermostat or diagnostic tool with similar capabilities should be used.
System Configuration
All factory installed DXM2 controls have their basic configuration parameters set as part of the factory manufacturing and test process. The System Configuration option under the communicating thermostat Installer menu provides the installer with the ability to adjust ECM target airflows for each operating mode, set control options, setup the loop configuration and parameters, and configure field replacement controls.
Airflow Selection – The Airflow Selection menu allows the installer to adjust the ECM target airflow for each control operating mode, as well as independently set the heating and cooling blower off delays.
ECM Airflows – Independent airflow selections may be made for each stage of heating operation, each stage of cooling operation with and without dehumidification, as well as constant fan operation. The DXM2 control has set minimum and maximum airflow limits for each operating mode, based on the unit configuration that may not be changed.
Heating / Cooling Off Delays – The heating and cooling mode blower off delay times may be independently adjusted by the user. Each delay time may be set between 0 and 255 seconds.
Option Selection – The Option Selection menu allows the installer to set selected control options.
LT2 Setpoint – The LT2 setpoint should be set to ANTI- FREEZE ONLY when the unit is configured as a
WATER.
Motorized Valve – The Motorized Valve option should be set to ON when a motorized water valve with end switch wired to the DXM2 Y1 is used with a communicating thermostat. For all other system configurations, the Motorized Valve option should be set to OFF.
Unit Configuration – Selections under the Unit
Configuration menu are normally set at the factory as a normal part of the manufacturing and test process. This menu allows the configuration to be modified for special applications, or to configure field replacement controls.
The Unit Configuration menu provides the ability to select the Heat Pump Family, Unit Size, Blower Type, and Loop Type. The Heat Pump Family, Unit Size, and Blower Type are needed to properly operate any particular unit configuration, especially those with ECM blowers.
Heat Pump Family – When replacing a control in the field, the Heat Pump Family value must be set for proper blower and loop operation. The valid family values (HEV/H and other Communicating units) are available for the user to scroll through to select the proper value.
Heat Pump Size – When replacing a control in the field, the Heat Pump Size value must be set for proper blower operation. After a Heat Pump Family has been selected, the valid Heat Pump Size values will be available for the user to scroll through to select the proper value.
Blower Type – When replacing a control in the field, the Blower Type value must be set for proper operation. The valid Blower Type values will be available for the user to scroll through to select the appropriate value from No Blower, ECM Blower, or PSC configurations.
Loop Configuration – When replacing a control in the field, the Loop Configuration value must be set for proper operation. The valid Loop Configuration values will be available for the user to scroll through to select the appropriate value from VS PUMP, MOD VALVE, or
OTHER.
Loop Configuration – The Loop Configuration menu allows the installer to set the operating parameters for either
an internal flow center, or a proportional water valve, depending on the unit configuration.
Heating Delta T – The Heating Delta T option allows the target delta T (EWT – LWT) value selection for operating in the heating mode. The DXM2 control has set minimum and maximum delta T limits that may not be changed. Cooling Delta T – The Cooling Delta T option allows the target delta T (LWT – EWT) value selection for operating in the cooling mode. The DXM2 control has set minimum and maximum delta T limits that may not be changed.
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