Page 330 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

You can connect to any one of the terminals R, Y, B and N as all of them are having continuity as
ascertained earlier.

2 Rotate the Megger at its rated speed and measure the insulation value and record it in Table 3.

The measured value should not be less than 1 megohm.

Table 3
S. No. Insulation resistance between windings Value in megohms
1 Between RYBN and field winding F1 & F2

TASK 4: Measure the insulation resistance between the windings and the body
1 Connect one of the prods of the Megger to any one terminal, RYBN and the other prod to the body/frame of
the alternator.
2 Rotate the Megger at its rated speed and measure the insulation resistance. Record it in Table 4.
Table 4

S. No. Insulation resistance between winding and the body Value in MW
1 Between armature winding R/Y/B/N and the body
2 Between field winding F1 & F2 and body

3 Connect the Megger prod to terminal F1 or F2 and the other prod to the body.
Rotate the Megger at its rated speed and measure the insulation resistance value, and record it in Table 4.

The measured insulation value should not be less than 1 megohm.

4 Compare these values of insulation resistance with those entered in the alternator maintenance card available
in the section, and discuss the variations in the reading with your instructor.

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CITS : Automotive - Mechanic Diesel - Exercise 18.2