E2 -External Coil Sensor Error - Toyotomi KURO Mini Service Manual

（2）E2 -external coil sensor error
Cause: The detection of short circuit or open circuit of external coil
sensor during the inspection of main external control panel, indicated
Explanation of
by "external coil sensor error".
error
Inspection path: Sensor→Sensor wire→Connectors→Main external
control panel
Tools required
Multimeter, 20KΩ standard sensor (25℃）
for inspection
Frequent
External coil sensor, main external control panel
problematic part
1. Check whether there's resistance problem, short circuit or open
circuit in the sensor; the resistance value shall with a reasonable range
(about 20KΩ for frequency conversion machine)
2. Check whether the sensor wire is broken.
3. Check whether the terminal connectors are well fixed; check
whether the weld between the terminal and the main control panel is
Inspection
loose, and pull the terminal slightly for inspection if necessary.
procedure and 4. Check whether the sensor is affected with damp. The coil sensor is
quite easy to be affected with damp in case the lead of coil sensor is
key points
above the copper pipe.
5. In case no standard sensor is available at present, replace the
temperature sensor of external coil by other sensor asides, and then
check whether the error still exists; if the error disappears, replace the
sensor; if the error still exists, check the main internal control panel
and change if necessary.
Most internal temperature sensors of the frequency conversion
machine have a resistance value of 20KΩ.
Do not use improper sensor during repairing and maintenance, or it
may led to the start of protection mode due to wrong temperature
sensing of the machine, or the protection error.
In case a sensor with the resistance value over 20KΩ is used, the
detected temperature will be much lower than the actual temperature,
Special attention
which may lead to the frequent entering of defrost mode, the illusory
defrosting or the protection error during the cooling process.
In case a sensor with the resistance value below 20KΩ is used, the
detected temperature will be much higher than the actual temperature,
which may lead to defrost error during the heating process, or the start
of protection during the cooling process.
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