Lennox LGA Series Unit Information page 16

Adjust relay amp setting according to value given on the blower motor nameplate. Proper
relay amp setting equals motor nameplate FLA X service factor of 1.15 X .95.
Use small slotted screwdriver to adjust control mode from automatic reset (A) to manual
reset (H).
Control must be in the manual reset mode (H) to perform a test. Press the red test button.
Green trip indicator should pop out. Press the blue reset screw to reset the relay.
P110
TB1
ROOM
THERMOSTAT (A2)
TB1 connects to P110. Room thermostat connects to TB1.
IMC AND ADD-ON BOARD LOCATION AND OPERATION
1 Blower
1 Compressor
1 Outdoor fan
SIEMENS OVERLOAD RELAY
BLUE RESET BUTTON IN
FACTORY-SET AUTO MODE
(Turn clockwise to H for
manual reset)
AMP ADJUSTMENT DIAL
FIGURE 5
IMC BOARD INPUTS AND OUTPUTS
A55
A56
P115
P111 P112
A55:
1 Gas valve
1 Electric heat section
A56:
Optional
Economizer
and/or Power
Exhaust Fan
FIGURE 6
Page 16
GREEN TRIP INDICATOR
(Flush with surface -- not tripped;
Above surface -- tripped)
RED TEST BUTTON
SENSORS
INPUTS
P114
P113
OUTPUTS
COMPRESSOR
SAFETY INPUTS
BURNER
INPUTS