TM-9-2320-273-34

TRUCK TRACTOR, LINE HAUL; LIGHT EQUIPMENT TRANSPORTER; TRUCK CHASSIS; MEDIUM EQUIPMENT TRANSPORTER

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE

DECEMBER 1980

TM-9-2320-273-34 - Page 157 of 801

TM9-2320-273-34

5-7. Bench Testing.

a.

Test Setup.

Because of the internal regulator used on this alternator, the test stand hookup

consists only of connecting the positive and negative output leads.

b. Preparation.

Before beginning the test, and after making the above connections, momentarily

flash the field by connecting a jumper between the diode trio terminal and the alternator positive output

terminal (fig. 5-36). This will restore the residual magnetism which may have been weakened by handling

or repair procedures.

TA 074031

Figure 5-36. Restoring Residual Magnetism.

c. Testing the Alternator (72- Volt dc Output).

Test the alternator as follows:

(1) Set the test stand speed so that the alternator is running at

580-620

rpm.

(2) Adjust the regulator output to 14 volts dc.

(3) Vary the load on the alternator between 1 ampere and 85 amperes and check that the

output matches the load.

d. Testing the Alternator with Transformer-Rectifier (24- Volt dc Output).

Check the 24-volt

charging output as follows:

(1) Set the test stand speed so that the alternator is running at 580-620 rpm.

(2) Adjust the regulator output to 28 volts dc.

(3) Vary the load between 1 ampere and 15 amperes and check that the output matches

the load.

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