Kaliburn SR-45i, User Manual

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Maintenance and Troubleshooting SR-45i User’s Manual
Chopper Test Procedure
The following test should be performed when all functions appear to be working
correctly but there is no output current. Before performing this procedure, check
all torch lead connections, torch consumables, pilot arc relay, spark at the spark
gap assembly, and primary disconnect fuses.
Warning: Only qualified maintenance personnel should perform the
chopper test procedure. The system utilizes potentially fatal A.C. and
D.C. voltages. All maintenance should be performed with safety in
mind. Be aware that the large blue electrolytic capacitors beside the
chopper assembly store large amounts of energy even after power has
been removed from the system. Wait at least five minutes after turning
off power, and then use a voltmeter to verify that the capacitors are fully
discharged before touching the chopper.
Note: Unless otherwise noted, leave connectors plugged into the circuit boards
while making voltage measurements.
1. Turn off all power to the SR-45i power supply.
2. Disconnect the torch leads from the Torch Minus and Pilot Arc connections
on the I/O p.c. board.
3. Turn off the gas supply.
4. Disconnect the primary wires of the high frequency transformer TR4.
5. Turn the mode switch to position number 9.
6. Install a jumper wire across the terminals of pressure switch PRS1 and
another jumper wire across the terminals of pressure switch PRS2.
7. Connect the positive lead of a voltmeter to the Work Ground connection on
the I/O p.c. board and connect the negative lead to the Torch Minus
connection. Configure the voltmeter to read D.C. voltage.
8. Use a jumper wire to give the system a start command. Install the jumper
between P8-3 and P8-4 on the rear of the power supply or between TB1-7
and TB1-8 on the sub-panel.
9. When the red D.C. Power light on the front panel illuminates, the voltmeter
should read +230 VDC. If the voltage reading is correct, the chopper is
working correctly (skip the rest of this test).
10. Turn off the primary power to the system and connect the positive lead of
the voltmeter to the positive side of the large blue filter capacitors C7 that
are mounted beside the chopper. Connect the negative lead of the voltmeter
to the negative side of capacitors C7.
11. Turn on the power supply and give the system a start command. When the
red D.C. Power light illuminates, the voltmeter should read +230 VDC. If
the voltage is incorrect, there may be a problem with CON1, CON2, TR1,
the diode bridge, or C7 (skip the rest of this test).
12. If the voltage across C7 is correct, then the input to the chopper is correct.
Turn the power off and move the negative voltmeter lead to the chopper
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