Specifications

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Typical Wiring Diagrams
Figure 29: MicroTech III Unit Controller with PSC Motor – 208/230/460/575-60-3 Unit Sizes 024-070
Drawing No. 668991202
Note: Thegraytintedareasinthewiringdiagram;DischargeAir(DAT)andReturnAir(RAT)Temperaturesensorsareeld-installed
onunitsconguredwithacommunicationmodule.TheLeavingWater(LWT)sensorisunit-mountedfromthefactory.
*Wiringdiagramsaretypical.Forthelatestdrawingversionrefertothewiringdiagramlocatedontheinsideofthecontrolsaccess
panel of the unit.
Legend
Item
Description
C1
Capacitor-Compressor
C2
Capacitor-Fan
CC
Compressor - Contactor
CM
Compressor - Motor
COS Condensate Overow Sensor
DA
T
Discharge Air Temp Sensor
EWT
Entering Water Temp Sensor
HP
High Pressure Switch
ISO-NO
Isolation V
alve - Normally Open
LED1
LED
Annunciator / Harness
LP
Low Pressure Switch
SL
TS
Suction Line
Temp Sensor
LWT
Leaving W
ater Temp Sensor
MIII
MicroT
ech III Main Board
R1
Relay - Fan Motor
RA
T
Return Air
Temp Sensor
RV
Reversing V
alve Solenoid
TB1
Power
Terminal Block
X1
Primary 24V
AC Transformer
_____
Standard Unit Wiring
_ _ _ _
Optional Wiring (by others)
T
able B
208V
RED
230V
ORG
460V
BLK/RED
575V
BLUE
Notes:
1.
Main board jumpers:
JP3 Geothermal
T
ransformer:
Unused wire to be capped.