Version 2.21
54 NPE Service Manual
4.9 Ladder Diagram
HOT
NEUTRAL
VENTURI
Relay 1
Relay 2
Relay 3
Relay 4
IGNITER
PUMP
Speed Control
Primary
MCU 1
MCU 2
DC24V
Flow Sensor
APS
DC12V
FAN
Water Adjust
Valve
Flow Control
DC15V
UART
Communication
Interface
Ready Link
Interface
Ready Link
Fan
Hall Sensor
Outlet
Thermistor 2
Inlet
Thermistor 1
Inlet
Thermistor 2
Outlet
Thermistor 1
Exhaust
Thermistor
EXT_PUMP
FRONT
PANEL
Communication
Interface
Relay 3
Relay 2
Relay 4
Driving Circuit
MGV1
MGV2
Relay 1
FSA Power
Switch
Flame Rod
150V
PWM
EMI
FILTER
DC5V
H.T.L
WD-PSS
SMPS
Primary
Secondary
3.15A
[NPE-180A/ 210A/ 240A]