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www.norcold.com
Polar Series N7V, N7X, N7XL / N8V, N8X, N8XL
Possible Cause:
The thermistor has been sensed as
inoperable, so temperature is being con-
trolled via backup operating system.
Fault Code - Flashing Temperature Setting
A flashing temperature setting indicator means the electronic
controls have sensed the fin thermistor to be inoperable. This fault
is only displayed while the optical display is “awake.” To “wake”
the display press and release either the Mode or Temperature
Set buttons. If there is a problem sensed with the thermistor the
temperature setting icon will flash ON and OFF. After 10-seconds
the control will revert back to the “sleep” mode. This fault can be
displayed in ANY MODE.
Should the thermistor be sensed inoperable the electronic controls
will ignore the thermistor and revert to a BOS mode (Backup Oper-
ating System). The BOS mode is an electronically controlled duty
cycle that allows the refrigerator to continue operating until such
time the thermistor can be repaired or replaced.
TROUBLESHOOTING FLOWCHARTS - N7LX AND N8LX MODELS, cont’d.
Are
wires and
connector
good?
YES
Clean or repair as needed.
NO
Check resistance at thermistor connector
with the thermistor packed in ice.
Check thermistor wire
assembly and connctor
for broken/dirty connections.
Is
thermistor
wire plugged
in?
NO
Plug in thermisor wire.
YES
NOR000711A
An alternate method would be to use an
infrared gun to measure the fin tempera
-
ture. Then compare that temperature with
the temperature indicated on Diagnostic
Screen #3. The temperature difference
should be 6° F or less. If not, thermistor
is bad.
NOTICE
set
Temperature setting flashes
on/off at one (1) second
intervals any time the user
interface (control) is “awake”.
Temperature* (°F)
Resistance* (k Ω)
85
8.1 - 9.0
80
9.1 - 10.0
75
10.1 - 11.0
70
11.1 - 12.0
60
12.1 - 13.0
* Approximate values
Temperature* (°F)
Resistance* (k Ω)
50
15.5 - 16.5
40
22.5 - 23.5
35
24.5 - 25.5
33
28.5 - 29.5
32
30.0 - 32.0
* Approximate values
This duty cycle will maintain refrigerator cooling by controlling the
length of time the heat source outputs (AC heater and propane gas
burner) are energized. The duty cycle, or length of time the cooling
cycle is regulated, can be manually controlled via the Temperature
Set button.
When a colder temperature is desired, changing the temperature
setting to the next “colder” setting will provide additional cooling by
lengthening the cooling cycle. For example, if the temperature set-
ting is set to 5, adjusting the temperature setting to the next colder
setting of 6 will lengthen the cooling cycle. When a warmer tem
-
perature is desired, changing the temperature setting to a warmer
setting shortens the cooling cycle. For example, if the temperature
setting is set to 4, lowering the setting to 3 will shorten the cooling
cycle.
