In Resistive Load Operation, The Output Voltage Is Not Regular - Cebora Power Tig 1540 DC-HF Service Manual

CEBORA S.p.A.

3.3.8 - In resistive load operation, the output voltage is not regular.

FOR THE FOLLOWING TESTS SET OPERATION TIG WITH HIGH FREQUENCY, LED
(C) LIT, BUT DISCONNECT THE HF TRANSFORMER (27) PRIMARY CIRCUIT
TERMINALS FROM "HT" TERMINALS OF POWER BOARD (29) TO AVOID HF
For the following tests use a resistive load capable of withstanding the maximum power
source current. The appropriate values are shown in the table.
Process Resistive load
resistance
TIG 0.107 ohm
MMA 0.183 ohm
OUTPUT VOLTAGE TEST ON RESISTIVE LOAD.
Turn knob (H) maximum clockwise (maximum output current).
Output terminal – power source (-) and output terminal + power source (+) = voltage values
as in the table, adjustable using the knob (H).
♦ Check the connection between the "NEG" terminal on the power board (29), HF
transformer (27) and "-" power source output terminal, and the connection
between the "POS" terminal of the power board (29) and "+" power source output
terminal. If you find loose connections, tighten and replace any damaged
terminals.
♦ Check the wiring between CN2 power board (29) and CN2 panel board (26).
♦ Check integrity and operation of potentiometers on panel board (26), performing
if necessary the POTENTIOMETER ADJUSTING TEST of par. 3.3.3.
♦ In TIG make sure start command operation (see par. 3.3.4).
♦ Check the mains voltage conditions and perform test of par. 3.3.1 if necessary.
♦ Replace power (29) and/or panel (26) boards.
♦ Regular operation.
3.302.212
WARNING
GENERATION.
NOTE
Maximum output
current
150 Adc
140 Adc
Correct?
YES
Power source
output voltage
+16 Vdc, approx.
+25.6 Vdc, approx.
NO
Condition
Start button pressed
Power source powered
12/01/06
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