Ladder Diagram - Navien NCB500-2S/37K Service Manual

4.6 Ladder Diagram

LIVE 240 VAC
EMI
FILTER
PWM
Transformer
DC24V
DC12V
DC 5V
Flow Sensor
WPS
Fan
Hall Sensor
Vent
Separation
Detector
Exhaust
Thermistor
Inlet
Thermistor 1
Supply
Thermistor
Outlet
Thermistor 1
Return
Thermistor
Outlet
Thermistor 2
Outdoor
Thermistor
HTL switch
Buner
Low water
Pressure switch
NEUTRAL
DC15V
BLDC-FAN
Primary
NCB500 Combi Series
Secondary
Only
Mixing
DC30V
Valve
Flow Control
Driving Circuit
MCU 1
UART
Communication
Interface
Relay 1
Igniter
Relay 2 Circulation Pump
Relay 3
3WAY
Speed Control
Water Adjustment
Valve
Flow Control
Flame rod
HTL switch
Heat Exchanger
WD-RSS
GAS V/V1
Relay 1
Relay 2
Relay 3
Communication
Interface
FRONT
PANEL
AC 130V
Trans
DC 9V
MCU 2
ROOM Controller
System Details 39