Thermal Dynamics CUTMASTER 60i Service Manual page 60

CUTMASTER 60i
4. No pilot, slow cycling of gas, about once every 5 seconds (No pilot connection).
a. No or intermittent connection somewhere between the torch tip and the stud labeled TIP on the inverter
board. This is an unlikely fault because if this connection is open during startup it results in E005 fault.
However if it becomes open after startup this could be the result. Look for pins or sockets pushed back
in the QD (torch handle quick disconnect) or the rectangular pin/socket in the ATC.
5. No pilot, brief preflow of gas followed by no gas and the DC symbol is on. (Pilot Switch not ON).
a. Inspect the parts. Check the start cartridge. Make sure the plunger moves freely. Try new parts or try a
different torch if available.
b. There is a possibility of an internal short in the torch lead or handle. If available, try another torch. Or
disconnect the torch from the plasma supply, remove the shield cup and tip. Measure at the torch head
from the electrode to the brass threads the shield cup screws on to. It should show open, several hundred
thousand ohms. If low resistance the torch is faulty.
c. Pilot IGBT switch may not be turned on. Measure voltage from TP21 (IGBT gate) to stud labeled TIP on
the Inverter board. If near zero disconnect the ribbon cable at J602 on the Inverter board. Measure TP21
again, it should be about 2.7V. If still zero replace the Inverter board.
d. If TP21 does measure 2.7V with J602 disconnected reconnect J602 and remove the ribbon cable from J100
on the Control & Display board. If TP21 still zero the ribbon cable is shorted pin 26 to 27. If TP21 not read
2.7V replace the Control & Display board.
6. No pilot, gas flows steady, DC symbol is on. (Short between tip and electrode).
Tip and electrode fail to separate when gas flows.
a. Inspect the parts. Check the start cartridge. Make sure the plunger moves freely. Try new parts or try a
different torch if available.
b. There is a possibility of an internal short in the torch lead or handle. If available, try another torch. Or
disconnect the torch from the plasma supply, remove the shield cup and tip. Measure at the torch head
from the electrode to the brass threads the shield cup screws on to. Should show open, several hundred
thousand ohms. If low resistance the torch is faulty.
7. No pilot, no gas flow, DC symbol is on. Torch is Automation (SL100SV) Advanced Menu, pressure.
a. If the automation torch solenoid doesn't open the parts will remain closed acting as a short. There will
not be a pressure fault as the SOL1 is on putting full pressure on the sensor. Go to the section Power ON,
Startup, section #4.b. & c. to test for faulty torch solenoid.
8. Extremely strong pilot, damages tip immediately.
The HCT1 current transducer outputs a voltage relative the current through the electrode. A problem with the
transducer, or more likely its harness, may prevent the voltage reaching the Inverter board allowing it to go to
full maximum output well above 60A even for pilot.
a. Confirm the harness is plugged into HCT1 and to J601 on the Inverter board. Check continuity of each
wire in the harness between HCT1 and J601. Refer to the unit schematic for harness wiring and colors.
b. If the harness is OK, reconnect J601 and with the unit at idle measure J401 (HTC1 end of the harness)
from J401-4 (common) to J601-1, should be +15V; and to J601-2, should be -15V.
c. Reconnect J401. With the unit at idle measure voltage from J601-4 (common) to J601-3, should be near
zero. If not replace the HCT1.
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SERVICE Manual 0-5475