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THEORY OF OPERATION
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THERMAL PROTECTION
Three normally closed (NC) thermostats protect the machine from excessive operating temperatures. These thermostats are wired in series and are con- nected to the control board. One of the thermostats is located on the heat sink of the output rectifier, one on the DC bus, and one on the output choke. Excessive temperatures may be caused by a lack of cooling air or by operating the machine beyond its duty cycle or out- put rating. If excessive operating temperatures should occur, the thermostats will prevent output from the machine. The yellow thermal light, located on the front of the machine, will be illuminated. The thermostats are
PROTECTIVE CIRCUITS
Protective circuits are designed into the Power Wave 455/R to sense trouble and shut down the machine before damage occurs to the machine’s internal com- ponents.
OVER CURRENT PROTECTION
If the average current exceeds 570 amps, the peak cur- rent will be limited to 100 amps until the average cur- rent decreases to under 50 amps or the system is re- triggered.
UNDER/OVER VOLTAGE
PROTECTION
A protective circuit is included on the Control Board to monitor the voltage across the input capacitors. In the event that a capacitor voltage is too high, too low, or becomes unbalanced
1.Capacitor conditioning is required. (This may be required if the machine has been off for a long peri- od of time and is connected for high input voltage operation.)
2.Voltage across a capacitor exceeds 390 volts. (This could result from high line surges or improper input voltage connections.)
3.Voltage across a capacitor is under 70 volts. (This would be due to improper input voltage connec- tions.)
4.Internal component damage.
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