AMX ENV-VST-C Installation Manual page 2

Wiring for AxLink
Follow these steps to connect the wiring into a captive-wire connector:
1. Strip 1/4 inch off the wire insulation for all four wires.
2. Tin 2/3 of the exposed wire.
3. Insert each wire into the appropriate captive-wire connector up to the
insulation.
4. Tighten the captive screws to secure the fit in the connector.
Use 18 AWG wire to connect the AxLink wiring from the thermostat to the
connector on the AxLink device as shown in FIG. 2.
FIG. 2
AxLink wiring
Note: The ViewStat Color Communicating Thermostat interfaces with a 24 VAC
power supply from the heating/cooling unit through its RC terminal. You should
not connect the power wiring from the AxLink device to the thermostat with the
intent of using the AxLink device to provide power to the thermostat. The L1
terminal on the thermostat can accept the AxLink +12VDC wire and you can
connect the wire to the terminal if you want to assure there are no loose wires
inside the thermostat, but you should not power the thermostat by running a
jumper to the RC pin.
Wiring Diagrams
ViewStat Color Communicating Thermostats are equipped with terminals RC,
RH, C, Y, W, G, O, B, S1, S2, L1, L2, L3, and L4. You can use terminals S1 and
S2 to accommodate a remote temperature sensor. Terminals L1-L4 connect to
the AxLink cable. The remaining terminals are used to control various types of
heating and cooling systems. You can use the thermostat with the following
types of heating and cooling systems:
• Single Stage Furnace and Single Stage A/C
• Dual Stage Furnace and Dual Stage A/C
• Roof Top Unit with Dual Stage Heat and Dual Stage Cool
• Boiler with A/C with Separate Transformers
• Single Stage Heat Pump
• Two Stage Heat Pump
• First Stage Radiant Floor Heat, Second Stage Furnace One Stage of
Cooling
Communication and Equipment Terminal Wiring Definitions
FIG. 3 displays the terminal layout for the thermostat.
FIG. 3
Terminal Layout
The following table lists the communication and equipment terminal wiring
definitions:
Communication and Equipment Terminal Wiring Definitions
RH 24 VAC in
RC 24 VAC in for AC relays. If a separate 24 VAC is not supplied to the RC
terminal, you should install a jumper from RH to RC.
C 24 VAC common
G1 Fan on 1. If you are using a single speed fan, connect it to the G1
terminal, since the fan speed is set to Low by default. On a multi-speed
fan, G1 is the lowest speed.
G2 Fan on 2. On a multi-speed fan, G2 is the medium speed.
G3 Fan on 3. On a multi-speed fan, G3 is the highest speed.
W1 1st stage heat or emergency heat for a heat pump system.
Communication and Equipment Terminal Wiring Definitions (Cont.)
W2 2nd stage heat
Y1 1st stage compressor
Y2 2nd stage compressor
B Reversing valve (heat)
O Reversing valve (cool)
DEH Dehumidify
HUM Humidify
S1 External thermistor. The ViewStat Color Communicating Thermostat
supports only one external sensor.
S2 External thermistor. The ViewStat Color Communicating Thermostat
supports only one external sensor.
L1 AxLink PWR. This terminal is optional for AxLink connections.
L2 AxLink AxP. This terminal is required for AxLink connections.
L3 AxLink AxM. This terminal is required for AxLink connections.
L4 AxLink GND. This terminal is required for AxLink connections.
Warning: Applying voltage to the external temperature sensor pins (S1 and S2)
can cause permanent damage to the thermostat.
Single Stage Furnace and Single Stage A/C
FIG. 4 displays the thermostat wiring for a system with a single stage furnace
and A/C.
FIG. 4
Single Stage Furnace and Single Stage A/C wiring
The thermostat automatically defaults to One Stage Furnace for the HVAC
System setting when you install it. For information about changing the HVAC
System setting, consult the Changing the Type of HVAC System section in the
ViewStat Color Communicating Thermostat User Guide.
Dual Stage Furnace and Dual Stage A/C
FIG. 5 displays the thermostat wiring for a system with a dual stage furnace and
A/C.
FIG. 5
Dual Stage Furnace and Dual Stage A/C wiring
Roof Top Unit with Dual Stage Heat and Dual Stage Cool
FIG. 6 displays the thermostat wiring for a system with a roof top unit with dual
stage heat and dual stage cool.
FIG. 6
Roof Top Unit with Dual Stage Heat and Dual Stage Cool
Boiler with A/C with Separate Transformers
FIG. 7 displays the thermostat wiring for a system with a boiler with A/C with
separate transformers.
FIG. 7
Boiler with A/C with Separate Transformers
Single Stage Heat Pump
FIG. 8 displays the thermostat wiring for a system with a single stage heat pump.
FIG. 8
Single Stage Heat Pump
Two Stage Heat Pump
FIG. 9 displays the thermostat wiring for a system with a two stage heat pump.
FIG. 9
Two Stage Heat Pump
First Stage Radiant Floor Heat, Second Stage Furnace One Stage of
Cooling
FIG. 10 displays the thermostat wiring for a system with first stage radiant floor
heat and second stage furnace, one stage of cooling.
FIG. 10
First Stage Radiant Floor Heat, Second Stage Furnace One Stage of Cooling
Changing the Type of HVAC System
The thermostat automatically defaults to One Stage Furnace for the HVAC
System setting when you install it. You can change the type of HVAC system you
are using, which activates certain features depending on which type of system
you have. This option should be set when the thermostat is installed for the first
time, and should not need to be changed after that. Perform the following steps
to change the type of HVAC system you are using:
1. From the Main screen, press Mode/Select until the Thermostat Mode
screen appears.
2. Use the navigation buttons to select Settings, and press Mode/Select.
The Settings screen appears.
3. Use the navigation buttons to select Advanced Settings. Press
Mode/Select to access the Security Code screen.
4. Enter the security code, and select Enter to access the User Preferences
screen.