Limit operation – Sears EF12F1900A2 User Manual
Page 9
Attention! The text in this document has been recognized automatically. To view the original document, you can use the "Original mode".
Blower Coils
Installation Instructions
Sequence Of Operation
Mode
Thermostat to Con
trol Board 24 volt
Control
State
Control Function
Electric H eat Only
Constant Blower
(Fan Switch ON)
G
On
Fan On.
Off
Fan Off.
Thermostat calls for
Heat
G & W1 & W2
On
Fan On, 1st Stage Of Heat On, then 2nd Stage Of Heat On.
Off
2ndthen1st Stage Of Heat Off. 6 sec delay, then Fan Off.
Cooling Only Unit With Electric Heat
Constant Blower
(Fan Switch ON)
G
On
Fan On,
Off
Fan Off.
Cooling Only Unit
(Thermostat calls for
Cooling)
Y&G
On
Compressor On, Fan On.
Off
Compressor Off, 60 Second Delay - Then Fan Off,
Cooling Only Unit
(Thermostat calls for
Heat)
G & W1 & W2
On
Fan On, 1st Stage Of Heat On, then 2nd Stage Of Heat On.
Off
2ndthen1st Stage Of Heat Off. 6 sec delay, then Fan Off.
Heat Pump Wit 1 Electric Heat
Heat Pump
(Thermostat calls for
Cooling)
Y & G & O
O n
Compressor On, Reversing Valve Energized, Fan On.
Off
Compressor Off, 60 Second Delay And Then Fan Off.
Heat Pump
(Thermostat calls for
Heat)
Y&G
On
Compressor On, Fan On
Heat Pump cannot
maintain proper temp.
Y & G & W1 & W2
On
1 sf Stage Of Heat On, then 2nd Stage Of Heat On
Electric Heat Tempera
ture satifised
Off
2nd then 1 st Stage Of Heat Off
Heat Pump
(Goes into Defrost
Mode)
Y & G & 0 & W 1 & W 2
O n
Reversing valve switches unit to cooling, 1st Stage Of Heat
On, then 2nd Stage Of Heat On
Off
Reversing valve switches back to heating, 2nd then 1st Stage
Of Heat Off
Heat Pump
(Room temp, satifised)
Y&G
Off
Compressor Off, 60 Second Delay And Then Fan Off.
Heat Pump
(Emergency Heat)
G & W1 & W2
On
Fan On, 1st Stage Of Heat On, then 2nd Stage Of Heat On.
Off
2nd then 1 st Stage Of Heat Off. 6 sec delay, then Fan Off.
NOTE: Electric Heat Elements are controlled by relays with a delay sequence from the logic board to provide sequencing between elements.
Limit Operation
The temperature limit responds to over-temperature conditions in the air duct. If the temperature limit trips, the electric heater relays will
be de-energized and the fan relay will be energized. Once the limit resets, the control will resume normal operation. If the limit trips four
times during a single call for heat, the control will go into a 1 hour soft lockout. During the soft lockout, the fan relay will respond to
thermostat inputs but the heater relays are disabled. If the control detects a limit trip during the soft lockout, the control will go into a hard
lockout. Once in a hard lockout, the fan relay is locked on and the heater relays are disabled. Turning the power to the unit off and then on
will clear this state.
442 01 2204 01