Specifications

Page 26 of 36 / IM 1049-4
Thermostat Connections
Figure 33: 7-Day Programmable Electronic Thermostat
(P/N 668375301)
MicroTech III Unit Control Board
Low Voltage Terminal Strip (Circuit 1)
W1
Y1
W2
Y2
G
Thermostat
Terminals
-
C
TB2
24VAC
Alarm Output
Heat 2
Heat 1
Cool 2
Cool 1
Fan
Tenant Override
24VAC Common
C
O
G
Y1
Y2
W1
W2
A
R
+
R
Ferrite Core Suppressor
(See NOTICE)
Notes: IncludesThermostatandWallPlate.
 Refertotheinstallation,operation&applicationguide
(LIA265)forthermostat668375301.
Figure 34: Non-Programmable Electronic Thermostat
(P/N 668375401)
MicroTech III Unit Control Board
Low Voltage Terminal Strip (Circuit 1)
W1
Y1
W2
Y2
G
Thermostat
Terminals
-
C
TB2
24VAC
Alarm Output
Heat 2
Heat 1
Cool 2
Cool 1
Fan
Tenant Override
24VAC Common
C
O
G
Y1
Y2
W1
W2
A
R
+
R
O
Ferrite Core Suppressor
(See NOTICE)
*Override (Optional)
Notes: IncludesThermostatandWallPlate.
 Refertotheinstallation,operation&applicationguide
(LIA266)forthermostat668375401.
* When remote reset of a lockout condition is required
at the wall thermostat, it will be necessary to utilize a
conductorbetweenterminal"O"onthewallthermostat
toterminal"O"ontheMicroTechIIIunitcontroller(non-
programmablestatonly).
For 50Hz units, it may be necessary to install a Ferrite Core
Noise Suppresor on the thermostat cord cable where it enters
the unit “Low Voltage” opening (see Figure 35). The Installer
is responsible for checking local codes to determine if a Noise
Suppressor is necessary to meet CE compliance.
NOTICE
Figure 35: Ferrite Core Noise Suppressor on Thermostat
Cord Cable
Ferrite Core Noise Suppressor
on thermostat cable
Low voltage, themostat wiring entry
Optional Remote Sensor (P/N 66720401)
1. Remove cover from remote sensor housing.
2. Select an appropriate location for mounting the remote
sensor.
3. Mount remote sensor unit using hardware provided.
4. Installtwostrandshieldedwirebetweenremotesensor
andthermostat.Shieldedwiremustbeused.
Do not run remote sensor wire in conduit with other wires.
 • Wire1shouldrunbetweentheS1terminalonthe
thermostat and the S1 terminal on the remote sensor
 • Wire2shouldrunbetweentheS2terminalonthe
thermostat and the S2 terminal on the remote sensor
 • ConnecttheshieldingofthewiretotheS2terminalon
the thermostat
5. Disablethemainsensor(R12)onthethermostatby
cuttingitfromthecircuitboard.
Figure 36: Optional Remote Sensor Wiring
S1
S2
S1
S2
Cut R12 from
circuit board
Remote Sensor
Thermostat
Wire 1
Wire 2