MCQUAY Service Guide Book    Controller Configuration 
 
33 
   
6.0 CONVERSION CONFIGURATION 
 
6.1 Auxiliary Heater Conversion
 
 
U1.5 Heatpump with Auxiliary Heater  
 
To convert the standard U1.5 heatpump PCB to 
auxiliary heater application, the following 
components need to be added onto the PCB: 
1. Heater relay (240V/20A) 
2. Transistor, 2SC945 
3.  Diode, IN4003  
 
 
 
 
 
 
Board U1.5 Heatpump with Auxiliary Heater 
 
 
 
 
Heater Relay 
(RLY 8) 
Transistor 
(Q3) 
Diode