Amada 1000ADP, Operation Manual

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CHAPTER 4: OPERATING INSTRUCTIONS
125ADP/300ADP/1000ADP DUAL PULSE RESISTANCE WELDING POWER SUPPLY
4-8 990-922
Section III: Operational Notes
Repetition Rate
The 125ADP, 300 ADP, and 1000 ADP Power Supplies monitor the overall repetition rate and do not
accept fire signals that occur at greater rates than listed in Appendix A, Technical Specifications . The
125 ADP does allow for two consecutive welds to be at a faster rate than the
Repetition Rate
. This faster
rate for two consecutive welds is listed in Appendix A as the
Hit Rate
. The user must maintain hit rates
below those specified.
Automatic Power Turn-Down
The user must limit the power dissipated in the automatic turn-down circuit to the 50W limit listed in
Appendix A, Technical Specifications . Rapid firing of different schedules with significantly different
energy level can exceed this limit. To calculate the total power dissipated in this circuit:
1. Determine how many times in one minute the schedule will change from a higher energy to a
lower energy.
2. Add up the total Watt-seconds of energy decrease in one minute.
3. Divide this number by 60 to determine the average Watts of power dissipated
Example: If there are 12 schedule changes per minute where the programmed energy
decreases from 300Watt-seconds to 100Watt-seconds, the total change is 2400 Watt-seconds
per minute. Dividing by 60 gives a resultant value of 40 Watts (Watt-seconds per second
equals Watts), which is within the capability of the unit.
Open Load Protection
CAUTION
When the unit is fired with an open secondary circuit, the energy from the capacitor
bank is
not delivered to the weld. Instead, it is absorbed by the internal circuitry of
the welder. If the unit were allowed to fire repeatedly into an open load with
significant weld energy, it could cause internal circuits to overheat and be damaged.
In order to prevent this potential failure mode, ADP units have open load protection features. When an
open load is detected by an ADP unit, the unit aborts the weld. The unit does not provide an error
message if this even occurs.
The threshold for detecting an open load is typically about 10-15 milliohms. If your application requires
operation with secondary circuits that exceed this resistance, please contact Amada Miyachi America for
assistance.