Thermal Dynamics CUTMASTER 60i Service Manual page 66

CUTMASTER 60i
6. E010, Low Output Current Fault
a. If the inverter board pilot IGBT is shorted some current will return through the IGBT bypassing the work
lead current sensor. Perform the resistance tests at #7 of the "Power Off Tests".
b. If the IGBT tests OK, fault may be the HCT1 current sensor or its wire harness. For 60A output the cur-
rent sensor output voltage at J601-3 (J601-4 common) should be 2.4V. If it is 2.4V and the current is not
60A, then the sensor is defective. If the voltage is higher than 2.4V the harness may be defective. Test for
continuity.
7. E012, Output Fault
While most faults will clear when the problem is resolved, E012 requires recycling the power after correcting
the cause. Circuits monitor the voltage between torch electrode and work. Less than about 30V during pilot or
attempting to pilot and transfer will set the fault. The pilot arc starts by passing current through the electrode,
via the start cartridge to the tip. Then gas flow forces the start cartridge away from the tip resulting in an arc
with voltage exceeding 30v by a significant amount. If the parts fail to separate in the required time the voltage
will remain low and the fault is set.
Common cause is failure of the torch parts to separate with gas flow. The fault requires shutting off the power
which you should do anyway while inspecting the parts. Check the start cartridge. Make sure the plunger
moves freely. Try new parts.
An automation torch (SL100SV) whose solenoid fails to open does not set a pressure fault but prevents the parts
from separating which can cause an E012 fault. Refer to Power ON section, step #4, Gas Purge, to troubleshoot
the torch mounted solenoid.
Another, probably rare, cause of E012 is a sudden loss of pressure while piloting or cutting such as when the gas
supply hose comes off or bursts. The parts come back together causing low voltage before the pressure sensor
detects the loss of pressure. If the fault cause is not from loss of pressure, try these steps:
a. Possible short in the torch lead or handle. If available, try another torch or disconnect the torch from the
plasma supply, then remove the shield cup and tip. Measure at the torch head from the electrode to the
brass threads that the shield cup screws on to. It should be open, several hundred thousand ohms. If low
resistance the torch is faulty.
b. A problem with the HTC1 current transducer causing its output to signal current when there is none can
also set the E012. With the unit at idle on the Inverter board at J601 measure voltage from J601-4 (com-
mon) to J601-3. It should be near zero. If it is positive refer to #8 in the section Pilot & Transfer under
"Some faults don't set a code" to test the transducer and its harness.
c. This would be rare but a short in the ribbon cable with the signal V_SENSE on pin 13 is shorted to gnd
(pin 14) can set the E012. Remove both ends of the ribbon cable and check resistance from pin 13 to 14.
It should be open.
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Art # A-13342
SERVICE Manual 0-5475