Nautel V10 User's Installation And Operation Manual

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Nautel V10 User's Installation And Operation Manual Manual pdf 123 page image

V10/V7.5/V5/V3.5 Installation and Operation Manual Page 5-19Section 5 System Level Troubleshooting Issue 3.5Possible Associated Faults:- A-D Rej Ld Shutback (V10/V5)- A-C Rej Ld Shutback (V7.5/V3.5)- E-H Rej Ld Shutback (V10)- E-G Rej Ld Shutback (V7.5)- O/P Rej Ld Shutback (V10/V7.5)5.5.3.9 Reject Load Power ShutdownA Rej Pwr Shutdown alarm occurs whenthe transmitter attempts to reduce theforward power below minimum due torepeated Reject Power Foldback alarms.The transmitter latches off. To reset thelatch condition, press the Reset soft keyin the Status screen. Whentroubleshooting a Rej Pwr Shutdownalarm, see troubleshooting tips for aReject Power Foldback alarm (see5.5.3.7) or check the control/display PWB(A43) detection circuitry.Possible Associated Faults:- Rej Pwr Shutdown5.5.3.10 High Reject Load TemperatureA Rej Ld Tmp High (various prefixesapply, depending on transmitter; seePossible Associated Faults below) alarmoccurs when a reject load/combinermodule’s temperature has exceeded102°C. In conjunction with this alarm, theHigh Temperature Latch threshold (102°C)will latch the transmitter forward power tominimum for FM+HD and HD modes;1500 W (V10), 1120 W (V7.5), 750 W (V5)or 560 W (V3.5) for FM mode, and theHigh Temp Latch alarm will be displayed.To reset, press the Reset soft key in theStatus screen. Refer to the Status andEvents Log screens for additional alarms,as an aid in troubleshooting. Refer to theparagraphs for those alarms for moreinformation.• If no other alarms are indicated, checkthe detection circuitry on the control/display PWB (A43).NOTEHigh reject load temperature is usually theresult of a combiner fan fail in conjunctionwith higher than normal reject load poweror resistor ring dissipation. Theseconditions are normally caused by RFpower module failure or removal. InV10/V7.5 transmitters, single IPA PAfailures (A3 or A4) or phasing mismatchescan also cause higher than normal rejectload power.Possible Associated Faults:- A-B Rej Ld Tmp High- B-C Rej Ld Tmp High (V7.5/V3.5)- C-D Rej Ld Tmp High (V10/V5)- E-F Rej Ld Tmp High (V10/V7.5)- F-G Rej Ld Tmp High (V7.5)- G-H Rej Ld Tmp High (V10)- High Temp Latch5.5.3.11 Combiner Top/Bottom Fan FailIf a Comb Top Fan Fail or Comb Bot FanFail alarm occurs, the fault is with the topor bottom reject load cooling fan (top –B11, bottom – B12). Troubleshoot asfollows:NOTEWhen testing for voltage on fanconnectors, the transmitter’s RF powerstage must be enabled (RF On).(a) Check for fan blockage. If the fan isfunctioning (compared to other fans),but the indicated speed is zero (seecombiner fan meters in main screen),suspect a problem with the fan’stachometer circuitry or the control/display PWB’s detection circuitry.(b) Measure voltage between pin 1 (+) andpin 3 (-) of fan supply connector [P85(B11) or P86 (B12) as applicable].• If the voltage is between 47 V and 53 V,the fan is probably defective. Replacethe fan (see 5.6).