ClimateMaster Tranquility TSV 070 - ClimaDry Modulating Reheat Option; ClimaDry Sequence Of Operation

climatemaster.com
47
Tranquility
®
20 (TE) Series
Rev.: June 5, 2020
THE SMART SOLUTION FOR ENERGY EFFICIENCY
ClimaDry
®
Modulating Reheat Option
ClimaDry
®
Sequence Of Operation
A heat pump equipped with ClimaDry
®
can operate
in three modes, cooling, cooling with reheat, and
heating. The cooling/heating modes are like any other
ClimateMaster WSHP. The reversing valve (“O” signal)
is energized in cooling, along with the compressor
contactor(s) and blower relay. In the heating mode the
reversing valve is de-energized. Almost any thermostat
will activate the heat pump in heating or cooling modes.
The DXM2 microprocessor board, which is standard with
the ClimaDry option, will accept either heat pump (Y,O)
thermostats or non-heat pump (Y,W) thermostats.
The reheat mode requires either a separate humidistat/
dehumidistat or a thermostat that has an integrated
dehumidication function for activation. The DXM2
board is congured to work with either a humidistat or
dehumidistat input to terminal “H” (DIP switch settings
for the DXM2 board are shown in table 6). Upon receiving
an “H” input, the DXM2 board will activate the cooling
mode and engage reheat. Table 7 shows the relationship
between thermostat input signals and unit operation.
There are four operational inputs for single stage units
and six operational inputs for dual stage units:
- Fan Only
- 1st Stage Cooling
- 2nd Stage Cooling
- 1st Stage Heating
- 2nd Stage Heating
- Reheat Mode
• Fan Only: A (G) call from the thermostat to the (G
terminal of the DXM2 control board will bring the unit
on in fan only mode.
• 1st Stage Cooling: A simultaneous call from (G), (Y1),
and (O) to the (G), (Y1), (O/W2) terminals of the DXM2
control board will bring the unit on in 1st Stage Cooling.
• 2nd Stage Cooling: A simultaneous call from (G),
(Y1), (Y2), and (O) to the (G), (Y1), (Y2), and (O/W2)
terminals of the DXM2 control board will bring the unit
on in 2nd Stage Cooling. When the call is satisfied at
the thermostat the unit will continue to run in 1st Stage
Cooling until the 1st Stage Cooling call is removed or
satisfied, shutting down the unit. Note: Not all units have
two-stage cooling functionality (e.g. GC series units).
• 1st Stage Heating: A simultaneous call from (G) and
(Y1) to the (G) and (Y1) terminals of the DXM2 control
board will bring the unit on in 1st Stage Heating.
• 2nd Stage Heating: A simultaneous call from (G), (Y1),
and (Y2) to the (G), (Y1), and (Y2) terminals of the DXM2
control board will bring the unit on in 2nd Stage Heating.
When the call is satisfied at the thermostat the unit
will continue to run in 1st Stage Heating until the call is
removed or satisfied, shutting down the unit. NOTE: Not
all units have two-stage heating functionality.
• Reheat Mode: A call from the Humidistat/Dehumidistat
to the (H) terminal of the DXM2 control board will
bring the unit on in Reheat Mode if there is no call
for cooling at the thermostat. When the Humidistat
Dehumidification call is removed or satisfied the
unit will shut down. Note: Cooling always overrides
Reheat Mode. In the Cooling mode, the unit cools and
dehumidifies. If the cooling thermostat is satisfied but
there is still a call for dehumidification, the unit will
continue to operate in Reheat Mode.
ClimaDry
®
Component Functions
The ClimaDry
®
option consists of the following components:
• Proportional Controller
• Supply Air Sensor
• Motorized Valve
• Loop Pump
• Hydronic Coil
The Proportional Controller operates on 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 of the supply air sensor.
The Loop Pump circulates condenser water through the
hydronic reheat coil during the reheat mode of operation.
In this application, the loop pump is only energized during
the reheat mode of operation. The Hydronic Coil is utilized
during the reheat mode of operation 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 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
[22.2°C], generally considered “neutral” air.