Specifications
Page 20 of 32 / IM 1060-3
Typical Wiring Diagram
Figure 17: MicroTech® III Controller with I/O Expansion 
Module & Communication Module 208/230, 460, 575-60-3 (1.5 hp only)
Legend
Item
 Description
CC1
Circuit 1 Compressor Contactor
CC2  Circuit 2 Compressor Contactor
CM1
Circuit 1 Compressor
CM2
Circuit 2 Compressor
COS 
Condensate Overow Sensor
HP
Circuit 1 High Pressure Switch
HP2
Circuit 2 High Pressure Switch 
IOEXP
I/O Expansion Board / Harness
LED1
LED 
Annunciator / Harness
LED2 
LED 
Annunciator / Harness
*RA
T
  Return 
Air Temp Sensor
*L
WT
Leaving W
ater Temp Sensor
LP
Circuit 1 Low Pressure Switch
  LP2 
Circuit 2 Low Pressure Switch
SL
TS 
Circuit 1 Suction Line 
Temp Sensor
SLTS2 
Circuit 2 Suction Line 
Temp Sensor
R1
  Fan Motor Starter
RV 
Circuit 1 Reversing V
alve Solenoid
R
V2 
Circuit 2 Reversing V
alve Solenoid
  TB1
Power 
Terminal Block
X1
  75 VA Transformer
*DA
T
  Discharge 
Air Temp Sensor
  *EWT
Entering W
ater Temp Sensor
Notes:
1.
“Run/Prg” Jumper to be in “Run” position
for normal operation
* Optional with Communication Module
MicroT
ech III Control Board
JP1
Open (Normal) Shorted (T
est Mode)
JP2
Shorted
JP3
Open (Std Range) 
Shorted (Geothermal Range)
JP4
Spare
JP5 
Open
JP6
Open
JP7
  Spare
JP8
Spare
I/O Expansion Module
JP1
Shorted
JP2 
Open
JP3
Open
JP4
Open
JP5
Open
JP6
Open
JP7
Spare
JP8
Spare
Drawing No. 910101586










