CenCon
45
OPERATION NOTES
The S-XM can control both the large (120-650) and small (35-90) sizes of humidifiers. The large sizes use a DJ
style burner and require the addition of a J-XM and CD-XM expansion module.
TERMINAL DESCRIPTION
Terminal Type Name
Description
Value
H N
Power Supply
24Vac Grounded Neutral
24 Vac
GND
Ground
Connect to chassis.
LmA B
Modbus
Internal Network
MHL
AI
Modulating High
Limit
Optional analog input for duct mounted high
humidity sensing.
0–10 Vdc
FbG
AI
Feedback Gas
Compares the ball valve actuator feedback signal to
the demand signal.
0-10 Vdc
MBV
AO
Modulating Ball
Valve
Modulating gas valve actuator output.
0-10 Vdc
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
CM
COM Relay Common
Relay input power common to valve outputs.
24/120 Vac
FV
DO
Fill Valve
Enable water fill valve.
24/120 Vac
MV
DO
Mixing Valve
Enable drain water tempering valve.
24/120 Vac
DV
DO
Drain Valve
Enable primary drain valve.
24/120 Vac
FVS
DO
Fill Valve Side
Enable side tank (SHX) fill valve.
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
DH+,DH-
AI
Direct Humidity
Input for direct control of humidifier output control.
0-10 Vdc
Dn1, Dn2
AI
Drain Sensor
Drain probe sensor input.
Ohms (Ω)
CP
AI
Condensate
probe
Condensate probe sensor input.
Ohms (Ω)
FWP
AI
Water probe
Fill water level sensor
Ohms (Ω)
LWP
AI
Water probe
Low water level sensor
Ohms (Ω)
MX1, MX2
AO
Maxitrol Valve
DC current output to the Maxitrol modulating valve.
mA
ECO
AO
ECM Demand
Electronically Commutated burner motor control
output signal.
0-10 Vdc
PWM
PWM
ECM rpm
feedback
Pulse width modulation feedback signal from
Electronically Commutated burner motor.
PWM
ECC
ECM Neutral
Neutral reference to ECO output signal.