Hypertherm MAX200 Service Manual - Manual (Page 74)

MAX200 Service Manual 3-33
6-94
MAINTENANCE
Voltage Divider Test Procedure (Machine-Torch Systems)
The voltage between the electrode and the workpiece during arc transfer is divided down by 100 in the MAX200
and sent to the THC board PCB9. Adjustments to the torch height are made by the THC board so that consistent
distance can be maintained between the torch and the workpiece.
In order to see if the voltage dividing is being done properly, perform the following procedure:
1. Press the OFF button on the MAX200 Power Supply.
2. Place a DC voltmeter between the positive and negative terminals on the I/O PC board (PCB5). See Figure
4-12 for location of PCB5. The positive and negative terminals have cables marked 45 (-) and 42 (+) attached
to them.
3. Press the ON button of the MAX200.
4. After all STATUS indicators light, press START.
5. When the arc transfers, record the voltage off of the meter.
6. Remove voltmeter from the positive and negative terminals.
7. Place voltmeter across pins 3(+)&4(-) of REC5 on PCB9. See Figure 3-15 for location of REC5 on PCB9.
8. Depress the START button again to start a second cut.
9. When the arc is transferred, record the voltage off of the meter. It should read 1/100th of the first reading.
Example: -130VDC at positive and negative terminals should read -1.3VDC between pins 3&4.
If the second reading is not 1/100th of the first reading, check pins, connectors and associated wiring between
REC1 of PCB5 and REC2 of PCB7.
Test Procedures (Cont.)