Carrier 42BJ ULTRA Series Installation Manual page 27

When a heating/cooling changeover switch is connected be-
tween the room thermostat and the water flow control valve,
the changeover between heating and cooling modes takes
place automatically in accordance with the following diagram.
∆: Differential: 11,1 K ± 3,3
CM: Cooling mode
HM: Heating mode
θ: Water temperature in °C
BROWN
BLACK
FM
CHANGEOVER
BLUE
RED BROWN
ACTUATOR FOR
COOLING VALVE
27