Alternator Diagnostic

8/14/2019 Alternator Diagnostic

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Technical Procedure Alternator Diagnostic Guide

62-50605-00 Rev B 7/23/99 Page 1 of 19

Purpose: The purpose of this technical procedure is to provide simple, easy-to-follow instructions onhow to troubleshoot and isolate faults in the alternator used on CTD truck and trailerrefrigeration equipment.

Scope: This procedure covers alternator normal operation and fault-finding steps for improperlyoperating alternators. It applies to all CTD authorized dealer technicians responsible forrepair of electrical systems on CTD truck and trailer refrigeration equipment.

Table of Contents

1. Alternator And Related Component Part Numbers

2. Normal Operation

3. Common Malfunctions, Symptoms, Causes, And Repairs

4. Component Testing

Appendix A: Alternator Summary Information

Test Equipment Requirements

1. Digital Multimeter

2. Ammeter D.C. - 0 to 10 amperes

3. Ammeter D.C. - 0 to 100 amperes

4. Field Rheostat - 0 to 50 ohms resistance, 50 watt capacity

5. Carbon Pile - capable of 0 to 150 ampere load

6. Battery Hydrometer - any commercial type, with temperature correction scale


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1. Alternator and Related Component Part Numbers

Table 1 lists the most common and current production alternator and related component part numbersas used on CTD truck and trailer refrigeration equipment.

Part Number Part Description

30-00409-00 through 13 37, 65 and 105 amp alternators

50-01127-03 3.08 inch alternator pulley



30-00409-43 CW fan

30-00409-57 CCW fan

30-00306-14 Bi-directional fan

30-00409-44 Voltage regulator

30-00409-30 Brushes

Table 1Alternator and Related Component Part Numbers*

*For a complete listing of all alternator and related component part numbers, including prior productionmodels, see Appendix A (incorporates information previously released via Service Bulletin).

2. Normal Operation

NOTE: The following information describes how the alternator should work under normal operatingconditions. The unit examples referenced are the NDA94 Phoenix Ultra model with thefactory installed alternator and pulley arrangement.

A. Alternator available amperage output is dependent upon the rpms that the alternator is turning.For example, an alternator rated at 65 amps when turning at 3000 rpms will be able to charge ata current rate of 60 amps. As the speed increases to 3300 rpms (normal operating speed whenengine is running at 1900 rpms), the alternator reaches its maximum rated output. As ambient(or engine compartment) temperature increases, the available output amperage decreases.

B. Alternator output voltage remains much more constant than amperage; alternator rpm has little

affect on voltage output. Voltage is varied by ambient temperature and current load, meaning thatif the current load is high, the voltage level is lower. For example, if the battery charge is low andrequires charging, the current flow from the alternator is high and causes the voltage to drop

slightly.

NOTE: See Figures 1 and 2 on the following page for amperage and voltage levels at varied rpmand ambient temperatures.

C. Normal alternator operation is dependent upon proper alternator application. Major factors

include good, clean, and tight alternator wiring connections at the alternator, unit ground,ammeter, and unit battery; proper belt tension and alternator rotation direction; and proper rpmlevels.


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0

10

20

30

40

50

60

70

80

0 1000 2000 3000 4000 5000 6000 7000ALTERNATOR SHAFT R.P.M.

OUTPUTCURRENT(AMPE

RESD.C.)

77F

199F

Figure 165 AMP Alternator RPM / Output Chart

Figure 2 shows upper and lower voltage limits for all alternators using 30-00409-44 regulators.

13.5

14.0

14.5

15.0

15.5

-40 -20 0 20 40 60 80 100 120

REGULATOR TEMPERATURE (C)

ALTERNATOR

VOLTAGE

Figure 2Alternator Tolerance Band for Regulated Voltage


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3. Common Malfunctions, Symptoms, Causes, and Repairs

Table 2 lists common malfunctions, symptoms, causes, and repairs.

MALFUNCTIONS SYMPTOMS CAUSES REPAIRS

ENG OIL (alarmmessage on micro)

Output terminal D+ of thealternator supplies 12VDC toMPL3 at the microprocessorprior to the unit starting.

Poor ground connection Broken or dirty alternatorground connection atalternator or starterground stud - repair orclean

When this occurs the unit willnot be able to operate in theauto start mode and thealarm ENG OIL will begenerated and displayed.

(Note: The D+ output shouldnot have voltage present untilthe alternator is turning at

600 rpms or higher).

This malfunction is oftenintermittent and may bedifficult to troubleshoot.

Metal debris inalternator, causing ashort circuit of therectifier diode bridge

Caution: always wear

safety glasses.In order to remove anydebris that may becausing a short circuit inthe alternator, first attemptto blow it out with cleancompressed air. It maybe necessary todisassemble thealternator and completelyclean it in order to removeall foreign material thatmay be causing a shortcircuit.

Defective alternator orvoltage regulator

Perform tests #1 & 2

ALT AUX (alarmmessage on micro) -Unit running

Low or no voltage on thealternator Aux terminal (D+)with unit running

Belt or pulley Loose or worn belt orpulleys replace

Or

No voltage at microprocessorterminal MPL3

Wiring problem Loose or dirty batteryconnections or looseconnections at thealternator or terminalMPL3 - repair or clean

Brush assembly Worn brushes replace

Defective alternator orvoltage regulator

Perform tests #1 & 2

ALT AUX (alarmmessage on micro) -Unit not running

No voltage at microprocessorterminal MPL3

Defective engine oilpressure switch (stockclosed/shorted)

Replace oil pressureswitch or check oilpressure switch wiring

SLIPPING ORSQUEALING BELTS

Excessive noise

Premature belt wear

Alternator bearingsworn

Loose or worn belt

Worn pulleys

Replace worn component

NOTE: Tests and procedures referenced in above repairs section are described in the following pages.

Table 2Common Malfunctions, Symptoms, Causes, and Repairs

4. Component Testing


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The following flow charts (Figures 3 and 4) serve as guides to fault finding alternator-relatedmalfunctions causing low or no battery charge or excessive battery charge. Test procedures 1 5 areincluded after the flow charts.

OK

OK

OK

OK

OK

Broken/loose/slipping alternator belt

No/Low Battery "Charge" Condition

Amp meter shows "no charge" or constant "discharge" with engine idling.

(Symptoms: dim lights, hard starting, alt aux alarm, low battery voltage)

Limited charging system operating time

Battery condition

Loose, dirty, or corroded terminal connection at battery,

alternator, ammeter, or unit ground

Worn, broken brushes

Adjust/replace belt

Charge battery as necessary

Clean, repair, replace as required

Clean terminals, charge or replace

Check fluid level

Replace brushes

NOT

OK

NOT

OK

NOT

OK

NOT

OK

Perform test procedures 1 through 5 to determine cause of

failure

NOT

OK

Figure 3No/Low Battery Charge Condition Flow Chart


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Dirty, loose or corroded terminals at regulator battery,

alternator, ammeter, or unit ground)

Excessive Battery "Charge" Condition

Amp meter shows constant "charge" with engine idling.

(Symptoms: frequent lamp burnout, excessive gasing, frequent water addition {in

excess of approx. 2 oz. per cell per 1000 mi.})

Clean, repair & replace as necessaryNOTOK

Regulator is likely to be "shorted"

Perform test procedure 4

OK

Replace regulator

NOT

OK

Figure 4Excessive Battery Charge Condition Flow Chart

The following tests and related diagrams (Figures 5 - 9) serve as guides to fault-finding other types ofalternator-related malfunctions.

A. TEST NO. 1ALTERNATOR/REGULATOR DEFECT ISOLATION TESTCONDITIONS: ENGINE NOT RUNNING

This test will determine whether the alternator or regulator is the cause of the charging systemfailure.

Disconnect battery. Remove the voltage regulator from the back of the alternator and disconnectboth green regulator leads at alternator F1 and F2 brush terminals (see Figure 5). Connect a

jumper lead from alternator brush terminal F2 to the alternator ground post. Set control knob offield rheostat in maximum position and connect in series to alternator brush terminal F1 as shownin Figure 5. The rheostat will protect the micro from any high voltages that may occur whenperforming this test.

Reconnect battery. Connect a DC voltmeter to the alternator as shown in Figure 6. Measure andnote output voltage with the engine off.

Start and run engine in low speed (equivalent to approximately 2000 alternator rpm). Slowlyreduce rheostat resistance, noting rise in voltage reading. (Stop test immediately if meterindicates more than 15.5 Volts.)


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Figure 5Alternator/Regulator Defect Isolation Test

If the output voltage increases over the initial value noted with engine stopped, the alternator isprobably good and the regulator is defective (perform Alternator Excitation Voltage Test - Test No.2). If entire rheostat resistance can be eliminated with no increase over initial voltage value, thealternator is probably defective and requires service. CAUTION: Limit time duration ofcharging test to less than one minute as relatively high voltages can quickly develop withsubsequent harm to the system, and check battery condition before running this test.System damage can result by performing this test with poor batteries.

Figure 6Alternator/Regulator Defect Isolation Test


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STOP HERE

At this point, if the alternator has been found to be faulty andshould be replaced, and if the unit/alternator is under warranty, nofurther testing is required.

The remaining steps included in this technical procedure areuseful for diagnostic evaluations of individual alternatorcomponent failures and for instructions on repairing the alternator.


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B. TEST NO. 2ALTERNATOR EXCITATION VOLTAGE TESTCONDITIONS: ENGINE RUNNING IN LOW SPEED EQUIVALENT TO 2000 ALTERNATORRPM

This test will determine if the regulator is faulty and if the excitation circuit within the alternator isfunctioning properly.

1) Prior to starting engine, connect an AC voltmeter across the two stator (phase) tap terminalsas shown in Figure 7.

2) Start unit3) If voltmeter indicates 0.05-1.50 volts for a no-charge condition, the alternator is probably good

and the regulator may be defective (regulator check is indicated). Typically, a voltmeter shouldread 7-13 volts for a properly operating alternator.

Figure 7Alternator Excitation Voltage Test

C. TEST NO. 3SHORTED RECTIFIER DIODE TESTCONDITIONS: ENGINE NOT RUNNING

Connect voltmeter as shown in Figure 8 (positive on terminal specified, negative on alternatorground).

1. Note battery voltage at alternator positive output terminal; should be approximately 12 volts(battery voltage).

2. Move positive voltmeter lead on either stator terminal. Correct voltmeter reading is zero volts.

If higher, rectifier diode is shorted.

The alternator must be removed from the unit for repair if a rectifier diode is shorted. Disconnectbattery ground cable prior to removing alternator.


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Figure 8Shorted Rectifier Diode Test

D. TEST NO 4FIELD CIRCUIT TESTCONDITION: ENGINE NOT RUNNING

Disconnect battery. Remove the voltage regulator from back of the alternator and disconnectboth green regulator leads at alternator F1 and F2 brush terminals (see Figure 9). Connect a

jumper lead from alternator brush terminal F2 to the alternator ground post. Place test ammeter inlow circuit, 1 to 10 amperes. Set control knob of field rheostat in maximum position and connect inseries to alternator brush terminal F1 as shown in Figure 9. The rheostat will protect the ammeterfrom damage if the field circuit is shorted.

Reconnect battery. Slowly reduce rheostat resistance, noting rise in ammeter reading. Stop test ifmeter indicates more than 3.7 amps for 37 amp unit or 3.5 amps for a 65 amp unit and 6.4 ampsfor a 105 amp alternator. If test ammeter goes over listed values, replace regulator.


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E. TEST NO. 5ALTERNATOR OUTPUT AND SYSTEM TESTCONDITIONS: ENGINE RUNNING - LOW SPEED

This test requires the test ammeter to be switched to the 0-100 ampere scale and placed in serieswith the alternator positive output terminal and battery positive terminal, as shown in Figure 10.Place load control knob of carbon pile to the off position before connecting load leads to thebattery terminals. Connect voltmeter as shown in Figure 10.

Start engine; run a few minutes at high speed to stabilize component temperature. Set enginethrottle to provide 3000 to 5000 alternator rpms. Apply carbon pile load to induce highestalternator current output. Note voltage at this point. See Table 3 below for the minimumacceptable (hot) output amperage and voltage.

ALTERNATOR AMPERAGE VOLTAGE

12V, 37 Amp 25-40 Amps 13.0-15.0 Volts

12V, 65 Amp 50-70 Amps 13.0-15.0 Volts

12V, 105 Amp 70-110 Amps 13.0-15.0 Volts

Table 3

Minimum Acceptable Output

If the alternator cannot provide the required output, it should be removed from the engine foroverhaul service. Reduce carbon pile load on battery immediately after testing to avoiddischarging battery.

System voltage drop, between the alternator and the battery, is tested with the alternatorproducing 10 amperes (adjust carbon pile to attain 10 amps). The maximum allowable voltagedrop between alternator and battery is .3 (three-tenths) volt.

Excess voltage loss is generally corrected by cleaning and tightening all circuit connections or theuse of heavier gauge output cables between the alternator and battery.

Figure 9Field Current Test


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Figure 10Alternator Output And System Test

NOTE: A carbon pile tester can be obtained from many tool distributors such as Snap-On or NAPA.It must be rated at a minimum of 1200 cold cranking amps (CCA).


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Appendix A: Alternator Summary Information

The following pages incorporate alternator information presented in past Service Bulletins.

Carrier Transicold has used a variety of alternator models over the years on truck and trailer refrigerationequipment, which sometimes leads to confusion regarding application, installation, replacement parts, etc.In order to remedy this, a summary of information for these alternators has been gathered together in thisbulletin.

A-1 is a reference chart, sorted by alternator part number, which includes information regardingalternator specifications, primary serviceable parts, and supercedures.

A-2 is a reference chart, sorted by pulley part number, which includes pulley dimensions andspecifications.

A-3 shows reference diagrams to be used during installation of any alternator included in thereference chart A-1.

Helpful Hints:

Serviceable Parts: Continue to refer to the Service Parts manual for the particular model unit youare working on for alternator related part numbers (brushes, pulleys, belts,etc.). Then consult charts A-2 and A-3 for additional information.

Pulleys & Shaft Sizes: There are two different alternator shaft sizes. Always try to use the correctreplacement alternator with the same shaft size, so that the pulley can beremoved from the bad alternator and installed on the new one. When pulleyreplacement is required, refer to the particular units Service Parts manual, aswell as charts A-1 and A-2, for assistance in pulley selection.

Fan Direction: Make certain of correct alternator fan rotation when selecting a replacement

alternator for a particular unit. Chart A-1 indicates the correct fan rotation, asviewed from the shaft end of the alternator. If the fan rotation is incorrect, anopposite direction fan should be installed (refer to same chart for partnumbers).

Wiring Connections: To assist in replacement alternator installation, label the alternator wiringconnections before removing the existing alternator. Do this by looking up theexisting alternator installation diagram in A-3, and label the wires with thenumbers 1 through 5 as shown. Then simply look up the installation diagramfor the replacement alternator and connect the wires as shown. Rememberthat some alternators do not require an excitation connection, so cap off thiswire (#3 on diagram) if it is not required on the replacement alternator.


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A-1Alternator Summary (Page 1 of 2)

Part Number Manufacturer Amperage Fan Fan Direction Regulator Brushes

30-00171-00 Motorola or Prestolite 35 30-00306-14 Bi-Directional 30-00351-01 30-50001-01



30-00281-00 Motorola or Prestolite 55 30-00306-14Bi-Directional

10-00265-01 30-50001-0130-00281-01 Motorola or Prestolite 55 30-00306-14 Bi-Directional 10-00265-01 30-50001-01












30-00351-05 Motorola or Prestolite 37 30-00306-14 Bi-Directional 30-00351-01 30-50001-0130-00355-00 Motorola or Prestolite 51 30-00306-14 Bi-Directional 10-00265-01 30-50001-01




30-00355-11SV Motorola or Prestolite 51 30-00306-14 Bi-Directional 10-00265-01 30-50001-01





30-00393-00 Bosch 65 Not Included N/A 30-00393-30 30-00393-30

30-00393-00RM Bosch 65 Not Included N/A 30-00393-30 30-00393-30

30-00393-01 Bosch 65 30-00395-00 Clockwise 30-00393-30 30-00393-30

30-00393-02 Bosch 65 30-00395-01 Counter Clockwise 30-00393-30 30-00393-3030-00409-00 Prestolite 105 30-00409-57 Counter Clockwise 30-00409-44 30-00409-30

30-00409-01 Prestolite 37 30-00409-43 Clockwise 30-00409-44 30-00409-30

30-00409-02 Prestolite 65 30-00409-57 Counter Clockwise 30-00409-44 30-00409-30



30-00409-05 Prestolite 37 30-00409-43 Clockwise 30-00409-44 30-00409-30







30-00423-00 Prestolite 65 30-00423-14 Bi-Directional 30-00423-02 30-00409-30

30-00423-00RM Prestolite 65 30-00423-14 Bi-Directional 30-00423-02 30-00409-30



30-50323-00RM Prestolite 37 30-00306-14 Bi-Directional 30-50324-01 30-00409-30


30-50325-00 Prestolite 51 Not Included N/A 30-50324-01 30-00409-30

30-50326-00 Prestolite 65 Not Included N/A 30-00423-02 30-00409-30


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A-1Alternator Summary (Page 2 of 2)

Part Number ShaftDiameter

Pulley Comments Supercedures

30-00171-00 0.63" 50-01127-00 S/S by 30-50323-00

30-00171-11 0.63" Not Included Less regulator, use pulley A,B,or C S/S by 30-50323-00

30-00228-00 0.63" 50-01127-01 S/S by 30-50323-00

30-00281-00 0.63" 50-01127-03 S/S by 30-50325-00

30-00281-01 0.63" 50-01127-00 S/S by 30-50325-00

30-00281-02 0.63" 50-01127-01 S/S by 30-50325-00


30-00306-00 0.63" Not Included Use pulley A,B,or C S/S by 30-50323-00


30-00306-03 0.63" 50-01127-03 S/S by 30-50323-00

30-00306-04 0.63" 50-01127-00 S/S by 30-50323-00

30-00306-05 0.63" 50-01127-01 S/S by 30-50323-00



30-00351-03 0.63" 50-01127-03 S/S by 30-50323-00

30-00351-04 0.63" 50-01127-00 S/S by 30-50323-0030-00351-05 0.63" 50-01127-01 S/S by 30-50323-00

30-00355-00 0.63" 50-01127-03 S/S by 30-50325-00

30-00355-01 0.63" 50-01127-00 S/S by 30-50325-00

30-00355-02 0.63" 50-01127-01 S/S by 30-50325-00


30-00355-11SV 0.63" Not Included Use pulley A,B,or C S/S by 30-50325-00





30-00393-00 0.67" Not Included Less fan, use pulley E or F S/S by 30-50326-00

30-00393-00RM 0.67" Not Included Less fan, use pulley E or F, remanufactured

30-00393-01 0.67" 50-01127-07 S/S by 30-50326-0030-00393-02 0.67" 50-01127-07 S/S by 30-50326-00

30-00409-00 0.63" Not Included Use pulley G or H S/S by 30-00409-11

30-00409-01 0.63" 50-01127-05 S/S by 30-00409-05

30-00409-02 0.63" 50-01127-03 S/S by 30-00409-10

30-00409-03 0.63" Not Included Use pulley G or H S/S by 30-00409-11

30-00409-04 0.63" 50-01127-12 S/S by 30-00409-10

30-00409-05 0.63" 50-01127-05

30-00409-06 0.63" 50-01127-03 S/S by 30-00409-10

30-00409-07 0.63" Not Included Use pulley C or H S/S by 30-00409-10

30-00409-08 0.63" 50-01127-12 S/S by 30-00409-10

30-00409-09 0.63" 50-01127-12 S/S by 30-00409-11

30-00409-10 0.63" Not Included Use pulley C or H

30-00409-11 0.63" Not Included Use pulley G or H

30-00423-00 0.63" Not Included Use pulley A,B,or C

30-00423-00RM 0.63" Not Included Use pulley A,B,or C, remanufactured


30-50323-00 0.63" Not Included Use pulley A,B,or C

30-50323-00RM 0.63" Not Included Use pulley A,B,or C, remanufactured

30-50324-00 0.63" Not Included Same as 30-50323-00, less regulator, use pulley A,B,or C

30-50325-00 0.63" Not Included Less fan, use 30-00306-14 Bi-Directional fan, use pulley A,B,or C

30-50326-00 0.67" Not Included Less fan, use fan from 30-00393, use pulley E or F


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A-2Alternator Pulley Summary

Pulley Part Number Pulley Diameter Pulley Groove Shaft Bore Diameter Replacement For

A 50-01127-00 2.87" 3/8" 0.63" 30-00171-02

B 50-01127-01 2.62" 1/2" 0.63" 30-00228-12

C 50-01127-03 3.08" 1/2" 0.63" 30-00306-12D 50-01127-05 3.21" 3/8" 0.63"

E 50-01127-07 3.08" 1/2" 0.67" 30-00393-38

F 50-01127-09 3.21" 3/8" 0.67"

G 50-01127-10 4.00" 5/8" 0.63"

H 50-01127-12 3.58" 1/2" 0.63"


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A-3Alternator Installation Diagrams

30-00171 or 30-00228

3

2

1

5

30-00281

5

1

3

2

30-00306

2

1

5

3

30-00351

3

2

1

54

30-00355

2

4

1

3

5

30-00363

1

4

5

3

2

2

1 Positive Output (+)2 Ground (-)3 Excitation4 Ac Tap (Do Not Use)

5 Indicator/Regulator(D+)


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30-0040930-00393

15

3

2

21

5

30-00423

21

4

5

3

30-50307

4

21

3

5




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30-50323

4

3

2

5

1

30-50324

4

21

5

30-5032630-50325

4

2

3

5

1

3

5

1 2

4



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