75 - "Coolant Pressure Too Low" On The Lcd Display; 76 - "Cooling Unit Not Connected" On The Lcd Display; 78 - "Gas Lo" Low Gas Pressure; 79 - "Gas Hi" High Gas Pressure - Cebora KINGSTAR 400TS Manual De Servicio

CEBORA S.p.A.
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Check the wiring between NTC1 of microswitch board (37) and sensor NTC1 on
the heatsink of power board (48). Check the wiring between NTC2 of
microswitch board (37) and sensor NTC2 on diode heatsink (27).
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Check that the heat sensors on the heatsinks of power board (48) and diode
assembly (27) are correctly fitted.
-
With the power source off and the heatsink of the primary IGBT assembly and
secondary diode assembly at room temperature, read the NTC1 and NTC2 heat
sensor resistance. To do this, disconnect the NTC1/NTC2 wiring from the
correspondingly named connector on microswitch board (37) and measure the
resistance present between the contacts of the newly-disconnected floating
connector. Expected value = 4.7 kohm (approximately) at 20-25°C room
temperature (if the temperature of the heatsink is different from 20-25°C, the
resistance measured will be different: lower than 4.7 kohm at a higher
temperature and greater than 4.7 kohm at a lower temperature).
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Replace the heat sensors and/or microswitch board (37).

3.6.24- 75 - "Coolant pressure too low" on the LCD display.

The pressure of the coolant in the cooling circuit is measured by pressure switch (23).
To analyse the corresponding circuit see TESTING PRESSURE SWITCH (23), section
3.5.15.

3.6.25- 76 - "Cooling unit not connected" on the LCD display.

If error "76" appears, check the wiring connected to connector J6 of precharge board
(39).

3.6.26- 78 - "Gas LO" Low gas pressure.

3.6.27- 79 - "Gas HI" High gas pressure.

Active only in "ROBOT" applications.
These alarms indicate that the welding gas pressure is lower than the minimum or
higher than the maximum permitted for operation.
- Check actual gas pressure;
- Make sure there are no blockages in the gas hoses to which the gas sensor is fitted;
- Check the connections of the gas sensor to motor control board (222);
- Replace motor control board (222) and/or gas sensor.

3.6.28- 80 - "Open" Wire feed unit casing open.

This alarm indicates that the wire feed assembly protective cover is open.
- Check the wiring between J10 of motor control board (222) and switch (226) on the
wire feed unit protective casing;
-
Check the voltage at J10 of motor control board (222), terminals 1(+) and 2(-) =
0 Vdc = cover closed, condition OK; +12 Vdc, approximately = cover open, alarm. If
not correct, replace switch (226) or motor control board (222).
- Check switch (226) and assembly cover are correctly fitted. If poorly positioned,
correct the positioning. Replace if defective;
- Replace motor control board (222)

3.6.29- 84 - "QC" flashing on panel H. Quality control failed

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