Open Circuit Voltage Check; Detailed Fault Finding / Error Indicators - Thermal Dynamics C-20A Cutskill Service Manual

6.04 Open Circuit Voltage Check

1. Attach shop air to unit.
2. Remove torch consumables from torch head and replace the shield cup.
3. Turn unit power on.
4. Measure terminal TB2, Pins 1 and 3. It should be 115VAC or 220VAC depending on input.
5. Measure output voltage on bridge diode (red and black). It should be 337VDC with 110VAC input and 298VAC
with 220VAC input.
6. Depress the torch trigger.
7. Check for illumination of the "SOL" LED and that the "EN" (Enable) LED brightens on the Logic PCB.
8. Measure output to Main Transformer Input. It should be 239VAC with 110VAC input and 210VAC with 220VAC
input.
9. Measure Main Transformer secondary voltage. It should be 207VAC with 110VAC input and 182VAC with
220VAC input.
10. Measure output O.C.V. to work. It should be 335VDC with 110VAC input and 291VAC with 220VAC input.
11. Turn off the unit power and replace the torch consumables removed in step 2 above.

6.05 Detailed Fault Finding / Error Indicators

Problem
Air Indicator is on
intermitant tone
Torch doesn't Pilot
and the LD1 LED light
on the Control PCB is
on
Torch doesn't Pilot
and the LD1 LED on
the Control PCB is not
on
"CO" LED on Control
PCB comes on when
not transferring.
TROUBLE SHOOTING
Check / Test
If the air supply and regulator setting
and or audible are OK, check the Pressure Switch
1 - Check torch consumables.
2 - Check all air supply related issues
before proceding.
3 - Check LD2 (EN) LED it should get
brighter with the torch trigger
depressed.
4 - Check OCV Voltage. If OCV Voltage
is OK check C/T 1 connection
Check all air supply related issues
before proceding.
Check Cable Connection (CN10) and
Current Sensor.
Recommended Action
1 - Replace Pressure Switch if
needed.
2 - If the Pressure Switch is OK
then replace the Control PCB
1 - Replace torch consumables
as needed.
2 - Change air related items as
needed.
3 - If OCV is not OK, follow OCV
check procedures in section
6.04
4 - If C/T 1 connection is OK,
replace the Control PCB
If there are no air related
issues, replace the Control PCB
If connection and Current
Sensor are OK, replace the
Control PCB
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