Dxm2 Controls - Heat Controller HEV Series Installation, Operation & Maintenance Manual

Installation, Operation & Maintenance
DXM2 Control - For detailed control information, see DXM2
Application, Operation and Maintenance (AOM) manual.
Field Selectable Inputs - Test mode: Test mode allows
the service technician to check the operation of the control
in a timely manner. By momentarily pressing the TEST
pushbutton, the DXM2 control enters a 20 minute test mode
period in which all time delays are sped up 15 times. Upon
entering test mode, the status LED display will change,
either fl ashing rapidly to indicate the control is in the test
mode, or displaying a numeric fl ash code representing the
current airfl ow if an ECM blower is connected and operating.
For diagnostic ease at conventional thermostats, the alarm
relay will also cycle during test mode. The alarm relay will
cycle on and off similar to the fault LED to indicate a code
representing the last fault, at the thermostat. Test mode can
be exited by pressing the TEST pushbutton for 3 seconds.
Retry Mode: If the control is attempting a retry of a fault,
the fault LED will slow fl ash (slow fl ash = one fl ash every 2
seconds) to indicate the control is in the process of retrying.
Field Confi guration Options - Note: In the following fi eld
confi guration options, jumper wires should be clipped ONLY
when power is removed from the DXM2 control.
Water coil low temperature limit setting: Jumper 3 (JW3-
LT1 Low Temp) provides fi eld selection of temperature limit
setting for LT1 of 30°F or 10°F [-1°F or -12°C] (refrigerant
temperature).
Not Clipped = 30°F [-1°C]. Clipped = 10°F [-12°C].
Alarm relay setting: Jumper 1 (JW1-AL2 Dry) provides fi eld
selection of the alarm relay terminal AL2 to be jumpered to
24VAC or to be a dry contact (no connection).
Not Clipped = AL2 connected to R. Clipped = AL2 dry
contact (no connection).
DIP Switches - Note: In the following fi eld confi guration
options, DIP switches should only be changed when power
is removed from the DXM2 control.
DIP Package #1 (S1) - DIP Package #1 has 8 switches and
provides the following setup selections:
1.1 - Unit Performance Sentinel (UPS) disable: DIP Switch
1.1 provides fi eld selection to disable the UPS feature.
On = Enabled. Off = Disabled.
1.2 - Compressor relay staging operation: DIP 1.2 provides
selection of compressor relay staging operation. The
compressor relay can be selected to turn on with a stage 1
or stage 2 call from the thermostat. This is used with dual
stage units (2 compressors where 2 DXM2 controls are being
used) or with master/slave applications. In master/slave
applications, each compressor and fan will stage according
to its appropriate DIP 1.2 setting. If set to stage 2, the
compressor will have a 3 second on-delay before energizing
during a Stage 2 demand. Also, if set for stage 2, the alarm
relay will NOT cycle during test mode.
HEV/H SERIES

DXM2 CONTROLS

On = Stage 1. Off = Stage 2.
1.3 - Thermostat type (heat pump or heat/cool): DIP 1.3
provides selection of thermostat type. Heat pump or heat/
cool thermostats can be selected. When in heat/cool mode,
Y1 is the input call for cooling stage 1; Y2 is the input call
for cooling stage 2; W1 is the input call for heating stage 1;
and O/W2 is the input call for heating stage 2. In heat pump
mode, Y1 is the input call for compressor stage 1; Y2 is the
input call for compressor stage 2; W1 is the input call for
heating stage 3 or emergency heat; and O/W2 is the input
call for reversing valve (heating or cooling, depending upon
DIP 1.4).
On = Heat Pump. Off = Heat/Cool.
1.4 - Thermostat type (O/B): DIP 1.4 provides selection of
thermostat type for reversing valve activation. Heat pump
thermostats with "O" output (reversing valve energized for
cooling) or "B" output (reversing valve energized for heating)
can be selected with DIP 1.4.
On = HP stat with "O" output for cooling. Off = HP stat with
"B" output for heating.
1.5 - Dehumidifi cation mode: DIP 1.5 provides selection of
normal or dehumidifi cation fan mode. In dehumidifi cation
mode, the fan speed relay will remain off during cooling
stage 2. In normal mode, the fan speed relay will turn on
during cooling stage 2.
On = Normal fan mode. Off = Dehumidifi cation mode.
1.6 - DDC output at EH2: DIP 1.6 provides selection for DDC
operation. If set to "DDC Output at EH2," the EH2 terminal
will continuously output the last fault code of the controller.
If set to "EH2 normal," EH2 will operate as standard electric
heat output.
On = EH2 Normal. Off = DDC Output at EH2.
1.7 - Boilerless operation: DIP 1.7 provides selection of
boilerless operation. In boilerless mode, the compressor is
only used for heating when LT1 is above the temperature
specifi ed by the setting of DIP 1.8. Below DIP 1.8 setting, the
compressor is not used and the control goes into emergency
heat mode, staging on EH1 and EH2 to provide heating.
On = normal. Off = Boilerless operation.
1.8 - Boilerless changeover temperature: DIP 1.8 provides
selection of boilerless changeover temperature setpoint.
Note that the LT1 thermistor is sensing refrigerant
temperature between the coaxial heat exchanger and the
expansion device (TXV). Therefore, the 50°F [10°C] setting is
not 50°F [10°C] water, but approximately 60°F [16°C] EWT.
On = 50°F [10°C]. Off = 40°F [16°C].
DIP Package #2 (S2) - DIP Package #2 has 8 switches and
provides the following setup selections:
2.1 - Accessory1 relay personality: DIP 2.1 provides
selection of ACC1 relay personality (relay operation/
characteristics). See Table 7a for description of functionality.
2.2 - Accessory1 relay personality: DIP 2.2 provides
selection of ACC 1 relay personality (relay operation/
characteristics). See Table 7a for description of functionality.
2.3 - Accessory1 relay personality: DIP 2.3 provides
selection of ACC 1 relay options. See Table 7a for
description of functionality.
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Heat Controller, Inc.