(g) Repeat steps (c) thru (f) except that theload current is increased to the overload current valuein Phase A only,Phases Band C remain at the ratedload current value.(h) Repeat step (g) except that the load isincreased to the overload current value in phase Brely.Phases A and C remain at the rated load valueof current.(i) Repeat step (g) except that the load isincreased to the overload current value in phase Conly.Phases A and B remain at the rated load valueof current.d. Results.The data sheets shall show, as aminimum, whether or not the circuit interrupter oper-ated, the time(s) required for the interrupter to oper-ate, the indication of the malfunction indicator, theoverload load condition(s) and the stabilization data.Compare the time(s) requirements of table 16-1.16-20. Circuit Interrupter Test (Overvoltage andUndervoltage)a. General. To protect the load from generatormalfunction (e.g. overvoltage or undervoltage) acircuit interrupter is connected between the generatorvoltage reconnection system and the generator outputterminals. A voltage sensing circuit operates thecircuit interrupter if an overvoltage or undervoltagecondition occurs and thus protects the load from agenerator malfunction.b. Apparatus.Instrumentation for measuringvoltage and frequency shall be as described and illus-trated in MIL-HDBK-705. Resistor(s), galvanometersmatching networks, an oscillogram (as describedand illustrated in MIL-HDBK-705, Method 106.1,paragraph 106.1. 3) and galvanometers having a min-imum flat frequency response (flat within plus orminus 5 percent) from DC to 3,000 Hertz and thevoltage divider transformer network will be required.c. ProcedureI.(Overvoltage)(1) Preparationfortest.(a) Locate and disconnect the input circuitto the input terminals of the overvoltage protectivesensing circuit and connect the apparatus as illustra-ted in figure 512, 3- I for one voltage connection.(b) Connect the frequency meter to the out-put terminals of the generator set.(2) Test.(a) Start and operate the set at rated fre-quency and nO load.(b) Close the switch (see figure 512. 3-I)and use resistance, R1 to adjust the voltage to theovervoltage value specified in table 16-1. Theset has provisions for shutdown upon an overvoltagecondition,it will be necessary to temporarily de-activate this provision to permit adjustment ofthe overvoltage value.This may be done by acti-vation of the "protective bypass" (Battle Short)switch.Do not deactivate the circuit interruptertrip circuitry.(c) Open the switch, reset the overvoltagecircuit and adjust the resistance, R2, until VoltmeterNumber 2 reads rated voltage.(d) Repeat (b) and (c) to assure that thespecified overvoltage and rated voltage settings arecorrect.(e) Set the oscillograph chart speed such thatthe individual waveform peaks are clearly visible.Set the timing lines to a minimum of 0.01 seconds perline or use a 60 Hertz time trace.Adjust the tracepeak-to-peak amplitude to a minimum of one inch (or25 millimeters).(f) Read and record both voltmeter readings.(g) With the oscillograph recording and thecircuit interrupter closed, close the switch. (Seefigure 512. 3-I).(h) Reactivate the shutdown provision ifu s e d .(i) The generator set contains an overvolt-age malfunction indicator, check and record its indi-cation.(j) Record whether or not the set shutsdown.(k) Open the switch, reset the overvoltagecircuit if necessary, restart the set if required, andclose the circuit interrupter.(1) Repeat steps (e) thru (k) above two addi-tional times.d. ProcedureII.(Undervoltage)(1) Preparationfortest.(a) Locate the input terminals of the under-voltage sensing circuit and connect the apparatus asillustrated in figure 512. 3-I.(b) Repeat step (b) of para. 16-20c. (1)(b).(2) Test.(a) Start and operate the set at rated fre-quency and no load.(b) Close the switch (see figure 512. 3-I) anduse the resistance, R1, to adjust the voltage to therated value.16-11
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