Caterpillar generators can be classified by three identification numbers: arrangement number, group number (part number) and serial number. The data in this manual is classified by the group number (part number) of the generator. The data is listed in alpha-numeric order. In order to locate the appropriate generator, refer to the index in the back of this manual. If you know only the arrangement number of the generator, refer to the Specifications, "Generator Identification" within this manual, which gives a cross-reference between the arrangement numbers and the group numbers. Each table that contains generator rewind data will refer to the connection diagrams for the main stator and the main rotor. The tables also refer to the connection diagrams for the exciter stator and the exciter rotor. For the connection diagrams, refer to the Specifications, "Connection Diagrams for Main Stator and Main Rotor" and the Specifications, "Connection Diagrams for Exciter".
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Do not overheat any of the generator components in order to burn off the epoxy varnish. Overheating the components can cause the laminations to become shorted together. This will damage the lamination assembly. |
Generator Identification
The generator identification plate is located on the left side of the generator.
When service is required, the information that is given on this plate should be used. The generator identification plate includes the following information: serial number, model number and the rating of the generator set. The generator set consists of the engine and generator. All pertinent generator data is also included on the plate in order to provide the information that is necessary to order parts.
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| Illustration 1 | g00728764 |
Generator Identification Plate | |
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| Illustration 2 | g00601027 |
Generator Serial Number Plate | |
Wire Standards
The wire size must be correct and the wire number must be correct. The wire size is listed in American Wire Gauge (AWG). The wires must meet the standards in NEMA"MW 1000-1997 MW 24-C". If you use wire that does not meet this standard, failure of the generator may result. The wires that are listed in this book are round wires, unless the wires are specified otherwise.
Varnish
The varnish must have a rating of class "F" for the following group numbers of generators: 106-3652, 108-3052, 121-3194, 144-0571, 4P-2238, 4P-2240, 4P-2242, 4P-2246, 4P-3015, 4P-4565, 4P-4571, 4P-7270, 4P-7272, 4W-0183, 4W-0184, 4W-6905, 4W-7049, 4W-7421, 4W-7422, 4W-7423, 4W-7424, 4W-7425, 4W-7427, 4W-7428, 4W-7429, 4W-7430, 4W-7431, 4W-7433, 4W-7434, 4W-8950, 4W-8951, 4W-8952, 4W-8953, 4W-8954, 4W-9069, 4W-9666, 4W-9667, 4W-9668, 4W-9669, 6I-2676, 6I-3088, 6I-3090, 6I-3092, 6I-3094, 6I-4827, 6I-4829, 6I-4833, 6I-4835, 6I-4839, 6I-4841, 6I-4843, 6I-4845, 6I-4847, 6I-4849, 6I-4851, 6I-4853, 7C-1601, 7C-1602, 7C-1603, 7C-1604, 7C-1605, 7C-1606, 7C-1607, 7C-1608, 7C-1609, 7C-1610, 7C-1611, 7C-1612, 7C-1613, 7C-1614, 7C-2269, 7C-2312, 7C-2617, 7C-2618, 7C-2619, 7C-2620, 7C-2621, 7C-2623, 7C-3484, 7C-3537, 7C-3538, 7C-3539, 7C-3540, 7C-3541, 7C-3542, 7C-4118, 7C-4121, 7C-4913, 7C-5094, 7C-7149, 7C-7151, 7C-7537, 7C-8892, 7C-8893, 7C-9126, 7E-5425, 7W-1877, 7W-3037, 7W-4367, 7W-4369, 7W-4371, 7W-4373, 7W-7521, 7W-7963, 7W-8671, 7W-8672, 7W-8673, 7W-8674, 7W-8675, 7W-8676, 7W-8677, 7W-8678, 7W-8679, 7W-8680, 7W-8681, 7W-8682, 7W-8685, 7W-8686, 7W-8687, 7W-8688, 7W-8690, 7W-8691, 7W-8692, 7W-8693, 7W-8695, 7W-8696, 7W-8697, 7W-8698, 7W-8699, 7W-8700, 7W-8701, 7W-8702, 7W-8743, 7W-8744, 9Y-0353, 9Y-0356, 9Y-0363, 9Y-0364, 9Y-0365, 9Y-0373, 9Y-0374, 9Y-0375, 9Y-1412, 9Y-3873, 9Y-3876, 9Y-7180, 9Y-9374, 9Y-9375, 9Y-9416, 9Y-9417, 9Y-9418, 9Y-9419, 9Y-9421 and 9Y-9422
All of the group numbers of generators that are not listed above have varnish of class "H".
A high strength 100 percent fill epoxy varnish is recommended.
Balance
Rewound rotors must be balanced dynamically. When you balance the rotor, the rotor's peak to peak displacement should be no greater than 0.0127 mm (0.0005 inch).
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If the rotor is not balanced properly, vibrations will result. These vibrations can damage the generator. |
Resistance
For the resistance checks, use a milliohmmeter such as a Wheatstone bridge or a Kelvin bridge. Most digital multimeters and analog multimeters are not accurate enough to measure the coil resistance.
The resistance values are correct only at the given temperature. If the winding temperatures are different from the temperatures in the table, use the following formula in order to find the actual resistance.
R2 = R1×(234.5 + T2) / (234.5 + T1);
R1 - The resistance that is listed in the table
R2 - The resistance that is actually measured
T1 - The temperature that is listed in the table
T2 - The temperature that is actually measured
Testing
High potential tests must be performed according to the following standards:
- NEMA"MG 1-1998 32.21"
- IEC"60034-6"