Hoshizaki 73168 Refrigerator User Manual


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5. Defrost Thermistor (cabinet) Malfunction Alarm (E8)
Ifthecontrolboarddetectsanopendefrostthermistor,"E8"isdisplayed.Whenthe
control board detects a shorted defrost thermistor, a 10-minute delay timer begins. After
the10‑minutedelaytimerexpires,"E8"isdisplayed.Tobypassthe10‑minutedelay
timer,movethepowerswitchtothe"OFF"position.Then,whilepressingtherail"SET"
button,movethepowerswitchtothe"ON"position.
•Ifthisalarmappears,rstmakesurethatthethermistorisproperlyconnectedtothe
control board.
•Ashorteddefrostthermistorisnotdetectedbythecontrolboardduringthe1sthour
after power is turned on. To bypass the 1-hour delay timer, move the power switch to
the"OFF"position.Then,whilepressingtherail"SET"button,movethepowerswitch
tothe"ON"position.
Reset Options
The alarm automatically resets when one of the following conditions is met:
•Thedefrostthermistorissecuredtothecontrolboard.
•Thedefrostthermistoriswithinnormaloperatingrange.Fordetails,see"II.E.Thermistor
Check."
•Afunctioningdefrostthermistorisinstalled.
Possible Causes
•Troublewiththedefrostthermistor.Forcheckoutprocedure,see"II.E.ThermistorCheck."
•Troublewiththecontrolboardreadingthedefrostthermistor.
E8 Alarm (short circuit) Reset
Under 10 min.
E8 (short circuit )
Detection Point
122°F (50°C)
Temperature
Display
E8
Blinking
E8 Alarm
(open circuit)
Reset
E8 Alarm Timer Start
E8 Alarm
Timer Start
Temperature Display
E8 Alarm (open circuit)
Detection Point
-67°F (-55°C)
E8
Blinking
10 min.
E8
Alarm
E8
Alarm
5a. Secondary Defrost Thermistor (Rail, not used)
The secondary defrost thermistor (located behind the wire cover) is not used for
operation of the unit. It is used for control board programming and should not be
removed.An"E8"alarmoccurswhenthesecondarydefrostthermistorisremovedor
fails.Fordetails,see"III.A.6.DefrostThermistor(cabinet)MalfunctionAlarm(E8)."
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