AMX ViewStat, Instruction Manual

Page: 48 / 76

Support Module Installation and Wiring
42
ViewStat Communicating Thermostat
Applications
Heat Pump Applications
If the support module is being used with a heat pump thermostat with auxiliary heat, the thermostat
can be configured to disable the use of auxiliary heat during warm weather and to lock out the
compressor when the outdoor temperature is too cold. This allows for the most efficient use of
energy.
At warmer temperatures, a heat pump will operate much more efficiently than the auxiliary heat. It
can save energy to disable auxiliary heat in some cases, for example, when returning from a setback
on a mild day. The temperature above which auxiliary heat is disabled is the auxiliary lockout
temperature or high balance point. Refer to the thermostat user manual for a detailed explanation.
Air-to-air heat pumps become less efficient as the outdoor temperature drops. The temperature at
which it becomes more efficient to use auxiliary heat instead of the heat pump is the balance point
or low balance point.
Configure the temperature sensor (T1/T2) that you are using to sense outdoor temperature to the
"Monitor" mode by setting the DIP switch 3 to the "off" position and the support module address to
number 1. The high and low balance points are set at the thermostat.
Humidity Control (VST-TRH only)
In order to set your thermostat up as a humidity controller, you will need at least one (up to four for
averaging) VST-TRH (temperature/humidity) support module(s) wired to the thermostat.
1.
Locate the VST-TRH Support Module in the area that you want to control humidity.
2.
Set the T3/T4 sensor (Humidity) Input to "Control" by moving the # 4 DIP switch to the "on"
position. Up to four T3/ T4 humidity sensors can be set to control and the reported values will
be averaged and displayed on the thermostat.
3. Once the humidity control sensor(s) have been wired to the ViewStat, the thermostat display
will change to indicate % RH instead of °F/°C. The thermostat mode selections will also
change to reflect humidity control. The modes are " Humidify ", " Dehumidify ", " Humidify or
Dehumidify " and " Off ". Humidification/Dehumidification set points are changed the same way
that temperature control set points would be changed.
None of the temperature sensors connected to this ViewStat can be set to control
mode because a control temperature input to the ViewStat will override a control
humidity input. Make sure all temperature sensors connected to this ViewStat are set
to "Monitor".