Tadiran Telecom Swift Inverter 9U, Service Manual

Page: 53 / 115

52
(13) F5 -Compressor top head sensor error
Explanation of
error
Cause: The compressor top head sensor is a compressor top head
temperature protection switch most of the time. It keeps closed (short
circuit) when the compressor temperature is normal and switches off
(open circuit) when the temperature is too high. The main external
control panel will indicate “compressor top head sensor error” when it
senses disconnection of the compressor top head protection switch.
Inspection path: Compressor top head sensor (temperature protection
switch)→Sensor wire→Connectors→Main external control panel
Tools required
for inspection
Pressure gauge, multimeter
Frequent
problematic part
System pressure, liquid deficiency, compressor top head sensor
(temperature protection switch), main external control panel
Inspection
procedure and
key points
1. First check if the compressor top head temperature is too high
(above 110
℃
) and causes action of the compressor top head sensor
(temperature protection switch); reasons why the compressor top head
temperature is too high may be: the system is deficient in liquid and the
compressor idles; the system is blocked and the pressure of the
compressor is too high.
2. After excluding the possibility of the system problem, please note
that the temperature protection switch is closed normally. Test if the
terminals of the sensor are in the short-circuit condition with the
multimeter. In the case of open circuit, then there is something wrong
with the sensor or lead wires.
3. Check if the sensor wire or the sensor connecting wire is damaged.
4. Check if the connecting terminal is connected firmly, the weld
between the terminal and the main control panel is loose; pull the
terminal slightly for inspection if necessary.
5. Disconnect the power supply and short circuit a metal with the
compressor top head terminal of the main external control panel. If the
compressor top head sensor error disappears after start up, then replace
the sensor; if the error still occurs, it’s probably the main control panel
problem, replace the main external control panel.
Special attention
The compressor top head sensor is just a temperature switch which is
highly reliable and is less likely to go wrong generally. Pay more
attention to the system pressure and the compressor temperature.