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875DP/500DP/500HV DUAL PULSE
RESISTANCE WELDING POWER SUPPLIES
990-290
7-1
CHAPTER 7
MAINTENANCE
Modification and Calibration
Unless you are a skilled technician, we suggest you telephone the Miyachi America Repair Department at the
telephone number shown in the Foreword of this manual for advice before attempting calibration and/or
modification.
WARNING:
Contact with voltages present in this power supply may cause serious or fatal injuries.
Cover Removal
It will be necessary to remove the outside cover to perform calibration or modifications. Use the
following procedure:
1
Set the front panel POWER switch to OFF.
2
Disconnect the power supply from its power source.
3
Remove the top two screws on each side of the cover.
4
Loosen the bottom two screws on each side and lift the cover straight upwards.
To disconnect the right half of the capacitor bank from the left half, refer to figure 7-1 and proceed as
follows:
WARNING:
After turning power OFF, wait at least 5 minutes for the capacitors to discharge before
starting this procedure.
1 Display units should be set to % Energy
not
Watt-Seconds.
2 Set the front panel POWER switch to OFF.
3 Remove the cover.
4 Remove Jumper A connecting the center terminals.