137
Appendixes
12.2 Wiring Diagram
Supply **Temp Sensor
High Temp Limit
(Burner)
Return **Temp Sensor
Exhaust 1 **Temp Sensor Outlet 2 **Temp Sensor
Air Pressure Sensor
High Temp Limit
Inlet Temp Sensor
CNJ1
CND1
CNK1
Cascade Line(RS-485)
Mixing Valve
Flow Valve
CNC2
CNB1
CONT2
CONT1
CNG1
CONW1
Flow Sensor
CONY1
AWS Valve
Water Pressure Sensor
Main Gas Valve1
Main Gas Valve2
Burner
Flame Rod
Ignitor
CNA1
CNI1
Ground
CNR1
Dual Venturi
CNO1
CNV1
ON
OFF
Boiler Pump FUSE
(250VAC_10A)
ZONE3 Pump FUSE
(250VAC_10A)
ZONE2 Pump FUSE
(250VAC_10A)
ZONE1 Pump FUSE
(250VAC_10A)
DHW Priority
Air Handler
Boiler Pump
CND1
CNP1
CNP2
CNA1
CON1
AC_N
ZONE1 Pump
ZONE2 Pump
ZONE3 Pump
Power Trans
AC_L
IN
OUT
AC_N
AC_L
IN
OUT
AC_N
AC_L
IN
OUT
Ground
Ground
Ground
N
FC
-H
(24V 75VA)
Ground
W
ARNING
ELE
CTRI
CAL SHOCK H
A
ZARD
Pumps must be ele
ct
rically
gr
ounded as
requi
red
by N
ational Ele
ct
rical
Cod
e.
*T/S: Thermostat **Temp: Temperature ***Factory jumper is connected as default. Remove it when using an additional appliance.
N
O
TICE
Ground
Main Switch
(AC)
External Input (AC 120V)
AC_L
CNX1
Recirculation
Pump
Ground
AC_L
IN
OUT
Front Panel
3-Way Valve
Fan
N
L
CON2
CON1
Fuse
(125V 20A)
Fuse
(250V 3.15A)
IN
OUT
AC24V
T/S INPUT
*T/S_3
T/S ZONE3
T/S ZONE2
T/S ZONE1
CNC1
CNC4
CNC5
AC24V
T/S INPUT
*T/S_2
AC24V
T/S INPUT
*T/S_1
*T/S Recirculation
AC24V
T/S INPUT
CNT1
CNT2
CNT3
SUPPLY
RETURN
OUTDOOR
System Supply **Temp Sensor
System Return **Temp Sensor
Outdoor **Temp Sensor
CNC6
Inlet Temp Sensor Outlet Temp Sensor
Vent Installation Detector
AC_N
CNV3
CNV2
CNV1
CNC3
ZONE3
LWCO
ZONE2
ZONE1
***LWCO
LW
CO
AC24V
AC24V
AC24V
AC24V
Zone Valve1
Zone Valve2
Zone Valve3
For your safety, turn off electrical power supply before making any electrical connections to avoid possible electric hazard. Failure to do so can cause severe personal injury or death.
Summary of Contents for NFC-250/175H
Page 67: ...67 Venting for Combustion Air WARNING The vent installation detector Detectable Undetectable...
Page 149: ...Memo...
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