D.C. GENERATION (cont)
(b) Inspection and Testing of Components
After disassembly, clean and visually inspect all parts for cracks, wear, distortion, and any
signs of overheating or mechanical interference.
1 Rotor: Test for grounded or shorted windings. Ground test can be made with test probes,
c o nnected in series with a 110-volt test lamp, an ohmmeter or any type of continuity
tester. (Refer to Figure 9.) There must no continuity between slip rings and rotor shaft or
poles. Test for shorted turns in the rotor winding by connecting a voltmeter, ammeter and
rheostat, as shown in Figure 10, or use an ohmmeter. Rotor current draw and resistance
are listed in the Alternator Service Test Specification paragraph. Excessive current draw
or a low ohmmeter reading indicates shorted windings. No current draw or an infinite
ohmmeter reading would indicate an open winding.
2 Rectifiers: A diode rectifier tester will detect and pinpoint open or shorted rectifiers with-
out going through the operation of disconnecting the stator leads. However, if a tester is
not available, test probes and a No. 57 bulb, connected in series with a 12-volt battery,
can be used in the following manner. Touch one test probe to a rectifier heat sink and the
other test probe to a lead from one of the rectifiers in that heat sink. Then reverse the
position of the leads. The test bulb should light in one direction and not light in the other
direction. If the test bulb lights in both directions, one or more of the rectifiers in that
heat sink is shorted. To pinpoint the defective rectifier, the stator leads must be discon-
nected and the above test repeated on each rectifier. Open rectifiers can only be detected,
when using the test bulb, by disconnecting the stator leads. The test bulb will fail to light
in either direction if the rectifier is open.
Testing Rotor for Ground
Testing Rotor for Shorts
Figure 9
Figure 10
PIPER AIRCRAFT
PA-32R-301/301T
MAINTENANCE MANUAL
24-30-00
Page 24-14
Reissued: July 1, 1993
1K14
AMMETER
RHEOSTAT
BATTERY
VOLTMETER
ROTOR
Summary of Contents for PA-32R-301T SARATOGA S
Page 26: ...CHAPTER 4 AIRWORTHINESS LIMITATIONS 1C1 ...
Page 29: ...CHAPTER 5 TIME LIMITS MAINTENANCE CHECKS 1C4 ...
Page 53: ...CHAPTER 6 DIMENSIONS AND AREAS 1D6 ...
Page 64: ...CHAPTER 7 LIFTING AND SHORING 1D21 ...
Page 68: ...CHAPTER 8 LEVELING AND WEIGHING 1E1 ...
Page 72: ...CHAPTER 9 TOWING AND TAXIING 1E5 ...
Page 76: ...CHAPTER 10 PARKING AND MOORING 1E9 ...
Page 80: ...CHAPTER 11 REQUIRED PLACARDS 1E13 ...
Page 92: ...CHAPTER 12 SERVICING 1F1 ...
Page 126: ...CHAPTER 20 STANDARD PRACTICES AIRFRAME 1G17 ...
Page 127: ...THIS PAGE INTENTIONALLY LEFT BLANK ...
Page 139: ...CHAPTER 21 ENVIRONMENTAL SYSTEMS 1H5 ...
Page 188: ...CHAPTER 22 AUTOFLIGHT 1J7 ...
Page 193: ...CHAPTER 23 COMMUNICATIONS 1J12 ...
Page 203: ...CHAPTER 24 ELECTRICAL POWER 1J22 ...
Page 263: ...CHAPTER 25 EQUIPMENT FURNISHINGS 2A13 ...
Page 269: ...CHAPTER 27 FLIGHT CONTROLS 2A20 ...
Page 332: ...CHAPTER 28 FUEL 2D11 ...
Page 363: ...CHAPTER 29 HYDRAULIC POWER 2E18 ...
Page 404: ...CHAPTER 30 ICE AND RAIN PROTECTION 2G16 ...
Page 470: ...CHAPTER 32 LANDING GEAR 3A13 ...
Page 550: ...CHAPTER 33 LIGHTS 3D24 ...
Page 562: ...CHAPTER 34 NAVIGATION AND PITOT STATIC 3E12 ...
Page 582: ...CHAPTER 35 OXYGEN 3F8 ...
Page 604: ...CHAPTER 37 VACUUM 3G6 ...
Page 616: ...CHAPTER 39 3G18 ELECTRIC ELECTRONIC PANELS MULTIPURPOSE PARTS ...
Page 620: ...CHAPTER 51 STRUCTURES 3G22 ...
Page 636: ...CHAPTER 52 DOORS 3H14 ...
Page 650: ...CHAPTER 55 STABILIZERS 3I4 ...
Page 662: ...CHAPTER 56 WINDOWS 3I16 ...
Page 670: ...CHAPTER 57 WINGS 3I24 ...
Page 688: ...CHAPTER 61 PROPELLER 3J18 ...
Page 704: ...CHAPTER 70 STANDARD PRACTICES ENGINES 3K10 ...
Page 708: ...CHAPTER 71 POWER PLANT 3K14 ...
Page 737: ...CHAPTER 73 ENGINE FUEL SYSTEM 4A13 ...
Page 749: ...CHAPTER 74 IGNITION 4B1 ...
Page 783: ...CHAPTER 77 ENGINE INDICATING 4C11 ...
Page 793: ...CHAPTER 78 EXHAUST 4C21 ...
Page 801: ...CHAPTER 79 OIL 4D5 ...
Page 805: ...CHAPTER 80 STARTING 4D9 ...
Page 819: ...CHAPTER 81 TURBINES 4D23 ...
Page 833: ...CHAPTER 91 CHARTS WIRING DIAGRAMS 4E13 ...