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4 Troubleshooting
Troubleshooting by alarm code
SMGB0120 rev.0 - 11/2017
117
4
Alarm code
SP-SP
Pump Interlock Abnormality
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
Examination of pump lock
Examination of pump
overcurrent relay
Check of thermistors
Check the wiring around
the pump and the
overcurrent relay for the
pump
Check PCBc (CPU PCB)
(PCB is normal)
No
No
No
No
Yes
Yes
Yes
The water is
flowing
The overcurrent
relay for the pump
(51P) is activated
230V are being supplied between pin 1 and pin
3 of connector PCN5 on PCBc (CPU PCB)
Temperature
difference between
inlet water temperature
thermistor and outlet water
temperature thermistor is
of less than 1.5ºC