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Technical Services
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Installation Instructions
Alternators 8LHA Series

General Information

Heavy duty, all electronic alternator systems in this series are designed for use with many combinations of system voltage and grounding. See Table 1 for the specifications of the model you purchased.

This alternator is equipped with a bidirectional fan which can rotate in either a clockwise or counterclockwise direction. A dual groove 3.3" pulley may be included. (if not, a suitable pulley may be purchased from your local Prestolite dealer - See Section II). For operation in a hazardous atmosphere, it has a completely enclosed brush assembly to prevent slip ring contamination and to shield any arcing. The rectifier assembly contains three positive and three negative diodes to provide more than ample current handling capability. The stator is insulated to provide maximum protection against shorting of windings to the laminations. The stator has one or more AC stator tap (R) terminals that can be used for tachometer input.

The alternator has a 7/8 shaft and a No. 305 bearing on the drive end. The rear bearing is fully sealed and permanently lubricated for the life of the bearing.

Some models include a fully transistorized integral adjustable voltage regulator which performs all of the operations necessary for complete control of the alternator output. The system is temperature compensated to permit the ideal charging rate at all temperatures. In the regulator, transistors replace the relays, contacts and springs which contribute to most of the failures in conventional electromechanical voltage regulators. It is capable of operating in an ambient temperature of 100 C to 40 C.

NOTE: On certain applications where this alternator is being installed in place of another brand or make of alternator, it may be necessary to rotate the rear housing relative to the front housing to insure a correct installation fit. See Section I for instructions.

If an ammeter is desired, Prestolite recommends the use of a good quality ammeter with a full scale slightly larger than the alternator's output rating. Two types are available; direct connected (where heavy current passes through meter); and shunt (remote) types. If the direct type is selected, a quantity of proper size wire sufficient to run from the output terminal of the alternator, up the meter and back to battery may be supplied with the meter or may have to be obtained. (See Table 2 for proper wire size for required length.) Consult ammeter installation instructions for additional information.

Section I - Rotating Spindle Mount Type Rear Housing (If Necessary)

To rotate the rear housing follow the steps outlined below:

1. Remove the four through bolts.

2. Remove brush cover plate and brush assembly.

3. Using a screwdriver, separate the stator from the front housing. Then remove the rear housing and stator assembly as a unit from the front housing and rotor assembly.

4. Reinstall the rear housing and stator assembly in the correct position.

5. Press the front and rear housings together and replace the through bolts (important: To prevent the through bolts from backing out or loosening, apply Loctite 240 or equivalent to the threads of the four through bolts.)

6. Reinstall the brush assembly and brush cover plate.

Model #Sales #Syst
8LHA2023V 110-255 12 N/P 6 14.4 130 DELTA A
8LHA2024R 110-251 12 P 5 14.4 90 DELTA A
8LHA2026V 110-277 12 N 4 14.4 130 DELTA B
8LHA2027R 110-278 12 N 4 14.4 90 DELTA B
8LHA2028V 110-279 12 N 4 14.4 130 DELTA B
8LHA2030R 110-281 12 N 5 13.3 84 DELTA A
8LHA2032V 110-309 12 N 4 14.4 130 DELTA B
8LHA2037V   12 N 4 14 130 DELTA B
8LHA2050VA1   12 N 5 14.2 130 DELTA B
8LHA2050VAS 110-454 12 N 5 14 130 DELTA B
8LHA2050VB   12 N 5 14 130 DELTA B
8LHA2050VBS   12 N 5 14 130 DELTA B
8LHA2051V   12 N 5 14.2 130 DELTA B
8LHA2051VA 110-472 12 N 5 14 130 DELTA B
8LHA2054U 110-455 12 N/P 5 14.2 105 DELTA A
8LHA2055R 110-429 12 N 5 14.2 84 DELTA A
8LHA2057V   12 N/P 5 14.2 160 DELTA A
8LHA2057VA 110-450 12 N/P 5 14 160 DELTA A
8LHA2063R 110-407 12 N 5 13.8 90 DELTA A
8LHA2070V   12 N/P 5 14.4 130 DELTA A
8LHA2070VA 110-555 12 N/P 5 14 130 DELTA A
8LHA2070VB   12 N/P 5 14 130 DELTA A
8LHA2073V 110-434 12 N/P 5 14.4 130 DELTA C
8LHA2077V 110-447 12 N 4 14.4 130 DELTA B
8LHA2078V 110-449 12 N 4 14.4 130 DELTA B
8LHA2079V 110-436 12 N 4 14.4 130 DELTA B
8LHA2080V   12 N 4 14.4 130 DELTA B
8LHA2081V   12 N 5 14.4 130 DELTA B
8LHA2084   12 N 5 14.4 130 DELTA A
8LHA2085V   12 N 4 14.4 130 DELTA B
8LHA2087VA   12 N 5 14.2 130 DELTA A
8LHA2088VA   12 N 5 14.2 130 DELTA A
8LHA2090UA   12 N 5 14.2 105 DELTA A
8LHA2091UA   12 N 5 14.2 105 DELTA A
8LHA2092VA   12 N 5 14.2 160 DELTA A
8LHA2093VA   12 N 5 14.2 160 DELTA A
8LHA2094V   12 N 5 14.2 130 DELTA A
8LHA2095V   12 N 5 14.2 130 DELTA A
8LHA2095V-N   12 N 5 14.2 130 DELTA A
8LHA2096V   12 N/P 5 14.2 130 DELTA A
8LHA2096VA 110555N 12 N 5 14 130 DELTA A
8LHA3025P 110-296 24 N/P 6 28.8 75 WYE A
8LHA3056R 110-428 24 N/P 5 28 85 WYE C
8LHA3071P 110-446 24 N/P 5 28.8 75 WYE A
8LHA3072P 110-433 24 N/P 5 28.8 75 WYE A
8LHA3076R 110-435 24 N/P 5 28.8 85 WYE C
8LHA3095R 110-466 24 N/P 5 28 85 DELTA C
8LHA3095ROK 310-466 24 N/P 5 28 85 DELTA C
8LHA3096U 110-459 24 N/P 5 28 110 DELTA C
8LHA3096UK 310-459 24 N/P 5 28 110 DELTA C
8LHA3161U 110-550 24 N 5 28 110 DELTA B
8LHC2010Z 110-254 12 N/P 7 14.4 160 DELTA A
    A B C

  FLAT WASHER 1/2" ID x 1" OD 3/8" ID x 1" OD 12MM ID x 25 MM OD
  LOCKWASHER 1/2" ID 3/8" ID 12MM ID
*Not Provided MACHINE SCREW 1/2-13 x 1-1/4" 3/8-16 x 1-1/4" M12-1.75 6H x 30MM

Section II - Pulley Selection

Figure 2 - Shaft Dimension Detail

Several pulleys are available from your Prestolite distributor or dealer to fit a wide variety of applications. There are single and double grooved pulleys which fit standard belt sizes from 3/8" to 1". Pulley blanks into which grooves must be cut to fit special belt sizes, are also available. Consult your Prestolite dealer.

In addition, any pulley which fits a standard 7/8" shaft can be used. For machining instructions on other than a standard pulley refer to Figure 2. The pulley is installed on the machine by removing the washer, locknut, and protective composition sleeve and then assembling the pulley on the shaft and tightening in place with the washer and locknut.

NOTE: Torque on pulley locknut - min. 40 to 50 foot pounds. Maximum do not exceed stamped rating on fan. Failure to regulate torque on impact wrench may result in damaged shaft. Also use pulley nut supplied with alternator.

Section III - Mounting of Alternator

Several mounting assemblies, including a mounting bracket and mounting hardware, are available from your Prestolite distributor or dealer to fit a wide variety of applications. Consult your local Prestolite dealer.

After the alternator mounting location has been determined, loosely attach the mounting bracket to the engine with the mounting engine bolts. Position the alternator mounting foot between the two ears on the mounting bracket with the alternator mounting bolts. Align the alternator pulley with the engine drive pulley as shown in Figure 3 and tighten the bracket mounting bolts, securing the mounting bracket to the engine. Loosely attach the alternator adjustment bracket to the alternator adjustment ear with the bolt, lockwasher and flat washer. Tighten the fan belt by applying pressure to the alternator front housing only and tighten the bolt to the adjustment ear. Tighten the alternator mounting bolts and retighten all other bolts to secure the installation.

CAUTION: Alternator will be permanently damaged if pressure is applied to rear housing. Tighten the fan belt by pressing against front casting near alternator fan.

Set belt tension per belt manufacturer's recommended specifications, and tighten all remaining bolts (contact manufacturer for specifications). If manufacturer's specifications are not readily available, set belt tension tight enough so that the belt on alternator fan pulley will not slip when attempting to rotate alternator by hand.

CAUTION: Alternator drive belts do stretch, particularly when they are new. Recheck belt tension from time to time. Belt slippage is more likely to occur with an alternator because of heavy charge rate possible at engine idle.

Section IV - Electrical Connections

Disconnect cables from battery before making following electrical connections. (See appropriate Figure - Table 1)

1. 1. Connect the existing generator output to the output terminal (1) of the alternator. Be certain that the proper size wire is used to carry full output current of alternator from positive output terminal to the battery. Consult Table 2. Connect ground to terminal (2). If regulator is not integral, connect regulator harness lead to alternator field terminal

Total Length
of Wire
in Feet
75 Amp 90 Amp 130 Amp 160 Amp
5 or less
5 to 10
No. 6
No. 4
No. 8
No. 6
No. 6
No. 4
No. 6
No. 2

2. Turn off all switches and electrical loads. Replace one cable on battery. Momentarily touch second terminal to other battery post. If no spark occurs, fasten cables to battery posts. If a spark occurs, recheck polarity of battery and all above steps until the fault is found.

WARNING: Reverse polarity of battery connections will cause damage to the rectifier diodes in the alternator. Be sure to check wiring before making battery connections.

3. After installation has been completed, check for proper operation. With ignition switch off, turn on headlights. Ammeter should now show discharge. If it shows charge, ammeter connections are reversed. Correct. When engine is started, ammeter should indicate charge.

Section V - Regulator Adjustment

After installation is completed, adjust regulator voltage by turning adjustment screw clockwise to increase, and counterclockwise to decrease voltage. See manufacturer’s specifications for correct voltage setting.

Figure 4: Wiring Diagram
Figure 5: Wiring Diagram
NEG/POS Ground
NEG/POS Ground

Figure 6: Wiring Diagram
Figure 7: Wiring Diagram
NEG/POS Ground
NEG/POS Ground

Section VI - Proper Ammeter Indication

After engine is started, the ammeter will usually show a rather heavy charge for a short time. The transistor regulator is permitting the alternator to charge heavily to replace the power taken from the battery during starting.

As the engine continues to operate, the amperes of charge will gradually drop to 0 to 4 amps as the battery becomes fully charged. This may take anywhere from 15 minutes to a few hours and will depend on the size and condition of the battery.

If a heavy electrical load (like a number of floodlights, an electric hoist motor, etc.) is turned on, the ammeter may show less charge or even discharge for a while. This is a normal condition, even if the load is only 40 to 50 amps.

If the load remains on, the amount of discharge will decrease and soon the ammeter will show a slight charge. If the load is now turned off, the ammeter will show a heavy charge for a short while and then gradually return to near zero. This is also a normal condition.

If the ammeter shows a continuing high charge rate, 10 to 20 or more amperes, for long periods of time, for hours of continuous operation, the condition of the batteries should be checked with a hydrometer. If the hydrometer treads below a full charge (1.260 approximately), the condition is normal - the alternator is just charging the batteries. If the hydrometer shows full charge (1.270 to 1.280), the voltage regulator may be defective.

If the ammeter shows a slight discharge consistently when the engine is operating at normal speeds, turn off all electrical loads, except ignition, for a few seconds. If ammeter jumps up to 30 to 85 amp charge, system is normal - the electrical loads are just absorbing all the alternator can generate. However, if ammeter should still show a slight discharge of 2 to 8 amps, there is a problem in the charging system. It is likely that the drive belt is either slipping or broken. If belt is OK, check for loose or broken electrical wires.

If the engine is required to run at slow idle for long periods while heavy electrical loads are demanded, the ammeter should be observed from time to time. If the ammeter shows a heavy discharge (more than 10 amps), it would be wise to increase the idle speed of the engine sufficiently to bring the ammeter to zero of to show a slight charge.

Keep in mind that when the batteries are normal and well charged, the ammeter should rest near zero, or show a very slight charge. With a transistor voltage regulator, there may be very little or no motion of the ammeter needle. This is also normal because the transistors maintain the voltage very constantly and smoothly.