System information

34
Geothermal Applications
ClimateMaster: Smart. Responsible. Comfortable.
• 2nd Stage Heating: A simultaneous call from (G), (Y1), and
(Y2) to the (G), (Y1), and (Y2) terminals of the DXM control
board will bring the unit on in 2nd Stage Heating. When the
call is satisfi ed at the thermostat the unit will continue to run in
1st Stage Heating until the call is removed or satisfi ed, shutting
down the unit. NOTE: Not all units have two-stage heating
functionality. 2nd stage heating for units with PSC fan and single
stage compressor is auxiliary electric heat (Y, W1, G).
• 3rd Stage Heating (ECM fan models only): A simultaneous call
from (G), (Y1), (Y2), and (W) terminals to the (G), (Y1), (Y2),
and (W1) terminals of the DXM board will bring the unit on in
3rd Stage Heating (compressor plus auxiliary electric heat).
• Reheat Mode: A call from the Humidistat/Dehumidistat to
the (H) terminal of the DXM control board will bring the
unit on in Reheat Mode if there is no call for cooling at the
thermostat. When the Humidistat/Dehumidifi cation call is
removed or satisfi ed the unit will shut down. NOTE: Cooling
always overrides Reheat Mode. In the Cooling mode, the unit
cools and dehumidifi es. If the cooling thermostat is satisfi ed but
there is still a call for dehumidifi cation, the unit will continue to
operate in Reheat Mode.
ClimaDry
®
II Component Functions
The ClimaDry
®
II option consists of the following componets:
• Proportional Controller
• Supply Air Sensor
• Motorized Valve
• Internal Loop Pump
• Hydronic Coil
1
Cooling input takes priority over dehumidify input.
2
DXM is programmed to ignore the H demand when the unit is in heating mode.
3
N/A for single stage units; Full load operation for dual capacity units.
4
Single stage unit: W = 2nd Stage backup elec. heat; Two-Stage units: W = 3rd stage backup elec. heat.
5
ON/OFF = Either ON or OFF.
Mode
Input Output
O G Y1 Y2
3
W H O G Y1 Y2
3
Backup
Elec Heat
Reheat
No Demand ON/OFF
5
OFF OFF OFF OFF OFF ON/OFF
5
OFF OFF OFF OFF OFF
Fan Only ON/OFF
5
ON OFF OFF OFF OFF ON/OFF
5
ON OFF OFF OFF OFF
Cooling 1st Stage ON ON ON OFF OFF OFF ON ON ON OFF OFF OFF
Cooling 2nd Stage ON ON ON ON OFF OFF ON ON ON ON OFF OFF
Cooling & Dehumidistat
1
ON ON ON ON/OFF
5
OFF ON ON ON ON ON/OFF
5
OFF OFF
Dehumidistat Only ON/OFF
5
OFF OFF OFF OFF ON ON ON ON ON OFF ON
Heating 1st Stage OFF ON ON OFF OFF OFF OFF ON ON OFF OFF OFF
Heating 2nd Stage OFF ON ON ON ON/OFF
5
OFF OFF ON ON ON ON/OFF
5
OFF
Heating 3rd Stage
4
OFF ON ON ON ON
4
OFF OFF ON ON ON ON
4
OFF
Heating & Dehumidistat
2
OFF ON ON ON/OFF
5
ON/OFF
5
ON OFF ON ON ON/OFF
5
ON/OFF
5
OFF
Table 6: ClimaDry
®
II Operating Modes
The Proportional Controller operates on a 24 VAC power supply
and automatically adjusts the water valve based upon the Supply
Air Sensor. The Supply Air Sensor senses supply air temperature
at the blower inlet providing the input signal necessary for the
proportional control to drive the motorized valve during the
reheat mode of operation. The Motorized Valve is a proportional
actuator/three-way valve combination used to divert the
condenser water from the coax to the hydronic reheat coil during
the reheat mode of operation. The proportional controller sends a
signal to the motorized valve based on the supply air temperature.
The internal loop pump circulates condenser water through the
hydronic reheat coil during the reheat mode of operation. In this
application, the internal loop pump is only energized during the
reheat mode. The Hydronic Coil is utilized to reheat the air to
the setpoint of the proportional controller. Condenser water is
diverted by the motorized valve and pumped through the hydronic
coil by the internal loop pump in proportion to the control
setpoint. The amount of reheating is dependent on the setpoint
and how far from setpoint the supply air temperature is. The
factory setpoint is 72°F [22°C], generally considered “neutral” air.
ClimaDry
®
II