Definitions Of Terminal Functions - Honeywell CT70 Wiring Manual

DEFINITIONS OF TERMINAL FUNCTIONS

Each terminal of the CT70 controls a different heat pump
function. Here is a list of the possible heat pump
functions:
Function
FIRST STG. HEAT:
AUXILIARY HEAT:
FIRST STG. COOL:
COMPRESSOR:
C/O VALVE HEAT:
C/O VALVE COOL:
EM. HEAT:
8
Definition
When this terminal is activated, the heat
pump is on and heating the living space.
When this terminal is activated, the
auxiliary heating source is on because the
heat pump is unable to meet the heating
demand of the living space.
When this terminal is activated, the heat
pump is on and cooling the living space.
When this terminal is activated, the heat
pump is on and either heating or cooling
the living space, depending on the system
switch position.
Heating Changeover Valve. This terminal
is activated when the system switch is in
the HEAT position. It provides changeover
in heat pumps that change over in
heating.
Cooling Changeover Valve. This terminal
is activated when the system switch is in
the COOL position. It provides
changeover in heat pumps that change
over in cooling.
Emergency Heat. This terminal is
activated when the system switch is in the
EM. HT position. In this situation, the heat
pump is not activated.