Selco Genesis 90, Repair Manual

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To perform calibration of the power source, follow the procedure below:
1. Be sure to have correctly replaced the damaged part and that the unit has been correctly repaired & tested (if replacing the reso-
nant logic board 15.14.152, check correct setting of the dip switches DS1).
2. Connect the unit to the mains.
3. Switch the unit on.
4. Set 90A as cutting current on the front panel.
5. Connect a static load of approximately 1.0W 8'000W (90V@90A) or strike a cutting arc (spark on a 4-5mm thick suitably sized
piece of iron and continue cutting at a moderate and regular speed): the generator should deliver approximately 90 ± 3A and
about "90" should be displayed as the actual cutting current.
6. Measure the output current from power source with an accurately calibrated ammeter clamp.
BE CAREFUL WITH CORRECT IDENTIFICATION OF THE TRIMMERS: P4 MAY NOT BE FITTED.
7. Current displayed: in this step figures displayed on control panel will not change while real output current changes by adju-
sting P3 trimmer: adjust P3 trimmer on resonant inverter control PCB 15.14.152 until value showed by external clamp amme-
ter matches the value showed on control panel (this value is the real output current and could be different from 90A value set
at step 5 above).
8. Current delivered: in this step figures displayed on control panel and those displayed on external clamp ammeter change simul-
taneously (they still match) and max output current is adjusted by P2 trimmer: adjust P2 trimmer on resonant inverter control
PCB 15.14.152 until 90A is displayed on both control panel and external clamp ammeter.
9. Disconnect any grid load or switch the cutting arc off.
10. Switch the power source off, seal the trimmers P2 & P3 and re-close the power source.
11. Perform some MMA and TIG welding tests to check correct operation of the power source.
WARNING!
P2 & P3 are very sensitive trimmers, thus little adjustaments will cause large output current variations!
Unless specified otherwise, all the measurements must be taken with the boards fitted, together with their connections!
Description, testing and replacement of the electronic boards, current calibration 43