Dxm2 Controls - Heat Controller DXM2 Application And Instruction Manual

Application, Operation, & Maintenance Manual

DXM2 Controls

THERMOSTAT COMPATABILITY - IT IS STRONGLY RECOM-
MENDED THAT A COMMUNICATING THERMOSTAT (7602-443)
BE USED WITH GEOMAX COMMUNICATING SYSTEMS FOR:
1. Four-wire connections between the thermostat, compres-
sor section (HTS), and air handler (WDG).
2. Confi guring, monitoring and diagnosing the system in
PLAIN ENGLISH on the thermostat.
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 and Fault LED displays will change.
The Status LED will either fl ash rapidly to indicate the
control is in the test mode, or display a numeric fl ash
code representing the current airfl ow if an ECM blower is
connected and operating. The Fault LED will display the
most recent fault condition in memory. Note: A fl ash code
of 1 indicates there have been no faults stored in memory.
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.
The test mode can be exited by pressing the TEST
pushbutton for 3 seconds. The test Mode can also be
entered and exited by cycling the G input, 3 times within a
60 second time period.
During Test Mode, the control monitors to see if the LT1
and LT2 thermistors are connected and operating properly.
If the control is in Test Mode, the control will lockout, with
Code 9, after 60 seconds if:
a) the compressor is On in Cooling Mode and the LT1
sensor is colder than the LT2 sensor. or,
b) the compressor is On in Heating Mode and the LT2
sensor is colder than the LT1 sensor.
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.
Note: Jumper 3 must not be clipped prior to adding
antifreeze to the water loop. Antifreeze protection to
10°F required. Clipping JW3 without antifreeze may
result in freeze damage and will void the unit warranty.
Water coil low temperature limit setting: Jumper 3 (JW3-
LT1 Low Temp) provides fi eld selection of temperature limit
DXM2 UNIT CONTROLS
setting for LT1 of 30°F or 10°F [-1°F or -12°C] (refrigerant
temperature).
Not Clipped = 30°F. Clipped = 10°F.
Alarm Relay Setting - Jumper 1 (JW1-AL2 Dry) provides
fi eld selection of alarm function when Alarm Relay is
energized.
Not Clipped = AL1 connected to R (24VAC) with Alarm
Relay active.
Clipped = Dry contact connection between AL1 and AL2
with Alarm Relay active.
JUMPERS (Set at Factory)
A0-2: Confi gure Modulating Valve (Optional)
Set A0-2 jumper (see Figure on page 5) to "IOV" if using
Internal Modulating Motorized Valve (optional).
DIP SWITCHES
Note: In the following fi eld confi guration options,
DIP switches should only be moved when power is
removed from the DXM2 Control to ensure proper
operation.
DIP Package #1 (S1)
DIP Package #1 is 8 position and provides the following
setup selections.
DIP 1.1: Unit Performance Sentinel Disable - Provides fi eld
selection to disable the UPS feature.
On = Enabled. Off = Disabled.
DIP 1.2: Compressor Relay Staging Operation - Provides
selection of Compressor Relay staging operation. The
Compressor Relay can be selected to turn on with 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. 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.
On = Stage 1. Off = Stage 2.
DIP 1.3: Thermostat Type (Heat/Cool) - Provides selection
of thermostat type. Heat Pump or Heat/Cool thermostats
can be selected. When in Heat/Cool Mode, Y1 is input call
for Cooling Stage 1, Y2 is input call for Cooling Stage 2,
W1 is input call for Heating Stage 1, and O/W2 is input call
for Heating Stage 2. In Heat Pump Mode, Y1 is input call
for Compressor Stage 1, Y2 is input call for Compressor
Stage 2, W1 is input call for Heating Stage 3 or Emergency
Heat, and O/W2 is the input call for RV (heating or cooling
dependent upon DIP 1.4).
6
Heat Controller, Inc.