CenCon
31
G-XM TIMING
Prepurge
60 seconds
Post purge
5 minutes
Flame failure
15 seconds lockout on ignition control and 60 seconds on burner
Pilot opening time
8 seconds
Open combustion air
proving
60 seconds
Improper gas valve wiring
2 seconds
Blocked condensate trip
5 minutes
Blocked flue
10 seconds trip and 1 minute burner alarm
Heat exchanger cool down 90 seconds if the discharge air is above 50° (10°C), else none.
Heat exchanger warm up
fan delay
75 seconds if ambient air is less than 40°F (4°C) and discharge temperature less
than 90°F (32°C), else no warm up.
Burner cool down
90 seconds
TERMINAL DESCRIPTION
Terminal Type
Name
Description
Value
H N
Power Supply
24 Vac
GND
Ground
Connect to chassis.
LmA B
Modbus
Internal Network
FbG
AI
Feedback Gas
Compares the ball valve actuator feedback signal to
the demand signal.
0-10 Vdc
FbA
AI
Feedback Air
Compares the combustion air actuator feedback
signal to the demand signal.
0-10 Vdc
MBV
AO
Modulating ball
valve
Modulating gas valve actuator output.
0-10 Vdc
MCA
AO
Modulating
combustion air
Modulating combustion air actuator output.
0-10 Vdc
CAS
DI
Combustion air
switch
Optional proof of combustion air flow.
24 Vac
BFS
DI
Blocked flue switch
Normally closed, opens on blocked flue.
24 Vac
EnH
DI
Enable heat
24V must be applied to allow heating function.
24 Vac
CB1, CB2
DO
Combustion blower
Start contact for the combustion air motor
contactor.
24/120 Vac
PV1, PV2
DO
Pilot valve
Disables the pilot flame once the main burner has
been established.
24/120 Vac
SR1, SR2
DO
Safety relay
Secondary safety lockout contacts
24/120 Vac
FR1, FR2
DO
Flame relay
Flame relay enable contacts.
24/120 Vac
FbV
DI
Feedback valve
Feedback signal from the safety shut off valve
(SSOV). Wired directly to valve.
24/120 Vac
VN
Valve neutral
Neutral feedback signal from the safety shut off
valve (SSOV).
HL
DI
High limit
Normally closed, opens on high temperature.
24 Vac
CP
AI
Condensate probe
Condensate probe sensor input.
Ohms (Ω)
