Honeywell Heat/1Cool User Guide - Page 10

HEAT PUMP THERMOSTAT CROSS REFERENCE/SELECTION GUIDE Equipment Equipment Function Terminals Power R 1st Stage Cool Y1 2nd Stage Cool Y2 Fan G 1st Stage Heat W1 2nd Stage Heat W2 Transformer Common C T8611M Terminals R Y2 G W2 C Y Heating Changeover B O R8222B Relay B M13231 Fig. 2. Installing an R8222B Switching Relay on heat pumps requiring heating mode changeover. Heat Pumps with Cooling Mode Changeover Here is how the switching relay allows the system to work properly: * The Y terminal is connected to the equipment terminal Y1 through the normally closed contacts on the R8222B Switching Relay. When the thermostat calls for cooling, the thermostat Y terminal activates the first stage of cooling. * The B terminal is connected to the coil terminals of the R8222B Switching Relay. When the system switch is in the HEAT position, the B terminal is energized, reversing the logic of the Chronotherm® III T8611G and T8611M Y terminal. Now when the thermostat calls for heating, the Y terminal activates the first stage of heating. Equipment Function Power 1st Stage Cool 2nd Stage Cool Fan 1st Stage Heat 2nd Stage Heat Transformer Common Equipment Terminals R Y1 Y2 G W1 W2 C T8611M Terminals R Y2 G W2 C Y Cooling Changeover O B R8222B Relay O M13230 Fig. 3. Installing an R8222B Switching Relay on heat pumps requiring cooling mode changeover. 70-6627 • 8