Planet ES-10024B-1 Maintenance Manual page 33

Aircraft Alternator
Maintenance Manual
3.2 Continued
Shorted or leaking RFI capacitor (airframe, engine, HET external filter): Remove capacitor and perform
capacitance check and wire lead to case resistance check. Replace filter capacitor if failed (external filter only). If
an internal PCB type filter, replace or overhaul alternator if failed. Drive coupler slipping: Inspect the condition
of the drive clutch. (as applicable) This part is supplied by the engine manufacturer. Improper tension supplied
by this clutch will allow slippage during high alternator output.
Drive Belt slipping: Inspect the condition of the pulley belt. (as applicable) The belt is supplied by the engine
manufacturer. Improper tension supplied on the belt may allow slippage during high alternator output.
Field circuit resistance too high: Check wiring and terminal ends and repair as necessary. Check condition of
the slip rings and clean. Check rotors as found in section 6 and if failed, replace or overhaul alternator.
Voltage regulator malfunction: Check the voltage regulator per the aircraft service manual and adjust if
necessary. If adjustment is not possible, check wiring and replace voltage regulator.
Accessory load too high for alternator rating: Refer to the AFM or POH (and aircraft service manual) for the
maximum allowable load specification. Reduce electrical load to meet these limitations.
Corroded or loose battery cable connector clamps: If connections to the battery are corroded, disconnect and
clean. Clean battery posts or terminals. If aluminum cable is installed, make sure that corrosion has not spread
under the insulation. If severe, replace cables or clamps. Tighten battery connections.
Low field voltage: Check the voltage regulator per the aircraft service manual and adjust if necessary. If
adjustment is not possible, check wiring and replace voltage regulator.
Needs battery maintenance: Perform normal battery maintenance. Check water level and electrolyte condition,
service per the aircraft service manual.
ES1031
Rev. A: 11 Aug. 2021
Table 3.2
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24-30-01
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