Service Manual

Table Of Contents
6. Service10-2019
113A062J683 (Issue 1) Copyright © 2019 Cummins Inc.
Tests Measurement Values
L1 to L2 Value should be equal to sum of L1 to N and
L2 to N measurements above ± 1% Ohms
Q1 to Q2
13 kW = 2.56 +/– 10% Ohms
17/20 kW = 1.45 +/– 10% Ohms
L1 to Q1 Infinity
L1 to Gnd Infinity
L2 to Gnd Infinity
Sense L1(W) - Sense L2(V)
13 kW = 0.24 +/– 10% Ohms
17/20 kW = 0.107 +/– 10% Ohms
Q1 to Laminations Infinity
*If a stator or rotor fails the initial test, repeat the test to check the validity of the initial
measurement before replacing the stator or the rotor.
3. Rotor Winding Resistance:
a. Connect each meter test lead to a separate slip ring.
b. Refer to Table 14 for resistance values. If test values do not match
measurement values, replace the alternator.
4. Main Winding to Quad Winding: Test for a short between the main windings
and the quad windings. Refer to the wiring diagram for connector pin locations
for quad windings. If shorted, replace the alternator.
5. Stator Ground Resistance Test:
a. Set the ohmmeter to the highest resistance scale, or use a megger.
b. Touch one test probe to the stack and, in turn, the other to each stator
lead. Refer to Table 14 for measurement values.
6. Stator Winding Resistance: Use a meter (Wheatstone bridge) having a
precision down to 0.001 Ohms to measure stator winding resistance values as
shown in Table 14.
7. Stator Winding for Grounds: With an ohmmeter, measure each winding to the
stator laminations to check for bad insulation. Refer to Table 14 for
measurement values.
NOTICE
This alternator is rated in accordance with UL 2200 (Stationary Engine
Generator Assemblies) or CSA C22.2 No. 100-04 (Motors and
Generators).
8. Verify Generator Set Performance: