Crown CT33098 Manual página 155

Note: The following operations require operators to master sufficient professional electrical knowledge and all-
round safety common sense and to possess valid qualification certificates in accordance with their capability and
knowledge. Before making repairs, we suggest that you first contact a local dealer to obtain approval.
Fault symptom
Machine is switched on:
• power indicator is not lit;
• fan does not work;
• no welding output�
Machine is switched on:
• power indicator is lit;
• normal welding output;
but:
• fan does not work�
Machine is switched on:
• power indicator is lit;
• fan is working;
but:
• output current is unstable and cannot
be controlled by the potentiometer when
welding�
Machine is switched on:
• power indicator is lit;
• fan is working;
• temperature protection indicator is not
lit;
but:
• no welding output�
Machine is switched on:
• power indicator is lit;
• fan is working;
but:
• temperature protection indicator is lit;
• no welding output�
Troubleshooting
1� Make sure that on / off switch is in "on" position, and it is not
damaged�
2� There is no input power supply�
3� Two cement resistor 7W47R, or the 24V 30A relay is damaged�
4� Auxiliary power modules, diodes BYV26E, K3878 (K2225) is
damaged�
5� Filter capacitor and silicon rectifier bridge damaged.
1� Check if the fan is damaged�
2� Check whether the fan power supply socket is voltage output�
1� Check if the potentiometer (1K) is damaged, or there is a loose
connection wire�
2� Potentiometer connection poorly contacts, especially the
connector assembly, check it�
3� Feedback circuit malfunction� Please contact the distributor or
the company�
1� Output connection circuit disconnection or poor contact�
2� Test whether the drain voltage of the four drive field tube is
about 14V�
3� Control circuit problem, please contact the distributor or the
company�
1� Overcurrent protection: switch off the machine until the
temperature protection indicator is off, then restart�
2� Overheating protection: wait for 5-10 minutes without switching
off the machine, and it will recover automatically�
3� Inverter circuit malfunction� Check if the IGBT module and
single tube have been damaged�
4� Secondary fast recovery rectifier individual breakdown, find
and replace the same type of rectifier.
5� Feedback circuit or control board malfunction, please contact
the distributor or the company�
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Remedy