Hitachi SAMURAI Series Service Manual page 125

4 Troubleshooting
Troubleshooting by alarm code
SP-SP
Alarm code
Alarm stop reason
• Pump operation feedback signal turns OFF while Pump operation signal (Y52P1) is ON.
?
N O T E
It is enabled after establishment of interlock.
• Pump operation feedback signal is not input within the time defined at "Waiting time for pump feedback" in optional
functions. Or in case that Cold (hot) water inlet/outlet temperature differential exceeds 1.5ºC, and water conduction
conditions have not been confirmed.
PCB monitoring position
PCBc (CPU PCB) PCN5
230V are being supplied between pin 1 and pin
3 of connector PCN5 on PCBc (CPU PCB)
Yes
117 SMGB0120 rev.0 - 11/2017
Pump Interlock Abnormality
(PCB is normal)
The overcurrent
No
relay for the pump
(51P) is activated
The water is
flowing
Temperature
difference between
inlet water temperature
thermistor and outlet water
temperature thermistor is
of less than 1.5ºC
Check PCBc (CPU PCB)
Examination of pump lock
Examination of pump
overcurrent relay
No
No Check the wiring around
the pump and the
overcurrent relay for the
Yes
No
Check of thermistors
Yes
4
pump