Charging System - cs-144 Chevrolet Chevy Van G1500

DESCRIPTION

The CS-144 generator with integral regulator (Scheme 3), features a high ampere output per pound of weight. It does not use a diode trio. The delta stator, rectifier bridge, and rotor with slip rings and brushes, are electrically similar to other CS-series generators. CS stands for Charging System, and 144 indicates the out-side diameter of the stator laminations in millimeters. The bearings are sealed with lifetime lubrication in both end frames. No periodic maintenance is required.

Scheme 3

Regulator voltage setting varies with temperature and limits system voltage by controlling rotor field current. When the field current is on, the regulator actually switches rotor field current on and oft at a fixed frequency of about 400 cycles per second to help control radio noise. By varying on-off time, correct average field current for proper system voltage control is obtained. At high speeds, on-time may be 10 percent and off-time 90 percent. At low speeds, with high electrical loads, on-off time may be 90 percent and 10 percent respectively.

A basic wiring circuit for the "PLIS" regulator is (Scheme 4) 'The "P" terminal connects to the stator. The "S" terminal may be connected externally to the battery to monitor voltage and make sure the regulator maintains an adequate voltage level to charge the battery. If the "S" terminal is not connected externally, integrated circuits in the regulator are used for sensing voltage.

Scheme 4

Both the "L" and "I" terminals serve to turn on the regulator and allow field current to flow when the switch is closed. The "I" terminal may be connected either directly to the switch, or through a resistor. The "P" circuit may be used with or without anything connected to the "L" circuit and with or without anything connected to the "L" terminal. When used, the "L" terminal must be connected through an external resistor such as the charging system indicator lamp. When a generator fault is detected, (voltage too high or too low, or no rotation), the regulator grounds the "L" terminal and activates the indicator lamp.

GENERATOR OUTPUT TEST

This test requires a standard test stand to operate the generator and a fully charged battery.

1. Install and connect the generator to the test stand (Scheme 5) The ground polarity of the generator and the battery must be the same. The carbon pile must be turned off to begin the test. Be sure that the generator BAT terminal is connected to the battery positive terminal (through the ammeter) and that the battery and generator are properly grounded.
2. Connect a 30 to 500 ohm resistor between the positive battery terminal and the terminal on the generator.
3. Operate the generator through the test stand, increasing speed slowly, and observe the voltage.
4. IF the voltage is uncontrolled and increases above 16 volts, the rotor field is shorted, the regulator is not working properly, or both. A shorted rotor field coil can cause problems in the regulator.
5. If the voltage is below 16 volts, increase speed and adjust the carbon pile to obtain maximum amperage output Maintain the voltage above 13 volts.
6. If the output is within 15 amperes of the rated out-put, the generator is good.
7. If the output is not within 15 amperes of the rated output, replace the generator.

DRIVE END FRAME

Tool required

J 28509-A Bearing Remover

Removal

Scribe mark to help locate the frame end parts in the same position during assembly.

1. Remove four through-bolts.
2. Remove rotor and drive end frame assembly from the slip. NOTE: On models with a slip ring end ball bearing on the rotor shaft, this bearing must be replaced with a new bearing any time the two halves of the generator are separated. If not replaced, the bearing may bind and fail due to distortion of Its outer tolerance rings. This does not apply to roller-type slip ring end frame bearings. Place the rotor in a vise and tighten only enough to permit removal of the pulley nut. NOTE: The rotor may be distorted if the vise is overtightened.
3. Remove nut and washer from the shaft.
4. Remove pulley, collar, fan, and outside collar from the shaft.
5. Remove drive end frame and the inside collar from the rotor shaft.
6. Remove three screws and the retainer from the drive end frame. (Scheme 8) Press the bearing from the drive end frame.
7. Remove slip ring end bearing (if equipped) from the rotor shaft using J 28509-A. (Scheme 9) Some models have a pressed on race that should not be removed.

Scheme 5

1. Remove three rectifier bridge to stator nuts.
2. Remove stator.
3. Remove one screw from the brush holder and two insulated screws from the regulator connector.
4. Remove brush holder, regulator, and connector from the end frame. see scheme 8
5. Remove BAT terminal nut from the insulated heat sink. see scheme 9
6. Remove "BAT" terminal from the outside of the frame.

Clean

Clean all metal parts except the voltage regulator, rectifier bridge, stator, rotor and bearing assemblies in a suitable solvent. Wipe or blow the parts dry.

Inspect

1. Inspect brush holder for damage. Clean brush holder. Make sure the brush pockets are clean. Clean brushes with a soft dry cloth.
2. Inspect brushes for wear. If the brushes are worn to 11 mm (0.4 in.) or less in length, replace the brush holder assembly. Use a retainer pin to hold the brushes in the holders.
3. Inspect brush springs for broken wire or corrosion.
4. Inspect slip ring end of the rotor shaft for overheating or scoring. If signs of overheating or scoring are present, replace the rotor. The slip ring end bearing must be replaced any time the two halves of the generator are separated.
5. Inspect drive end bearing for roughness, looseness, or wear. If the condition of the bearing is in doubt, replace it.
6. Inspect windings for burned insulation. Replace the rotor or stator if either looks burned. Burned insulation appears as very dark or blackened wiring. A strong acidic odor will be apparent.
7. Inspect terminal connectors for corrosion or breaks.
8. Inspect windings on the stator for chipped insulation. If the chipped area is small and the rest of the stator is OK, repair the stator with insulating varnish.
9. Inspect slip rings for scoring, wear or pitting. If the rings are dirty, clean with a 400 grain or finer polishing cloth. Spin the rotor and hold the polishing cloth against the slip rings until they are clean. If scored, worn, or pitted, true the rings in a lathe to 0.05 mm (0.002 in). Finish with 400 grain or finer polishing cloth. Blow away all dust.
10. Inspect rotor and stator windings electrically as described under "Electrical Tests," in this section.
11. Inspect generator housing for cracks, warping, or other damage.
12. If the regulator, brush assembly, or connector needs replacing, it will have to be unsoldered from the other two components. Use as little heat as possible to protect the regulator. see scheme 10

Scheme 6

ELECTRICAL TESTS

Except as stated, make the following tests with an ohmmeter on the low range scale.

Rotor Field Winding Tests

The rotor may be tested electrically with a self-powered test lamp or an ohmmeter. see scheme 11

Scheme 7

Open Winding Test

To test for opens, connect the test lamp or ohmmeter to each slip ring. If the lamp fails to light, or if the ohmmeter reading is high (infinite), the winding is open. Replace the rotor.

Grounded Winding Test

Connect a test lamp or ohmmeter from one slip ring to the shaft. If the lamp lights, or if the reading is low, the rotor winding is grounded. Replace the rotor.

Short Circuit or Resistance Test

Test the winding for short circuits or excessive resistance by connecting a battery and ammeter in series with the edge of the two slip rings. Note the ammeter reading and refer to " SPECIFICATIONS " in this section. An ammeter reading above the specified value indicates shorted windings.

An alternate method is to check the resistance of the field by connecting an ohmmeter to the two slip rings. If the resistance reading is above the specified value, the winding has excessive resistance; if below the specified value, the winding is shorted. The specified resistance value can be determined by dividing the voltage by the current.

Remember that the winding resistance and ammeter readings will vary slightly with winding temperature. If the rotor is not defective, but the generator fails to supply rated output, the problem is in the rectifier bridge, If the rotor fails any of the above checks, replace it.

Stator Test

Test the stator with a self-powered test lamp or an ohmmeter. see scheme 12 If the ohmmeter reads low, or if the lamp lights when connected from any stator lead to bare metal on the stator frame, the stator is grounded.

An Ohmmeter cannot be used to test the delta stator for shorts or opens. Noticeable discoloration on the assembly usually indicates a problem in the stator windings.

Scheme 8

Rectifier Bridge Test

To test the rectifier bridge, connect an ohmmeter to the grounded heat sink and one of the three terminals, pressing down firmly on the flat metal clip. see scheme 13 Observe the ohmmeter adding and reverse the lead connectors to the grounded heat sink and the same metal clip. If both readings are the same, replace the rectifier bridge. A good rectifier bridge will give one high and one low reading. Repeat this procedure between the grounded heat sink and the other two terminals, and between the insulated heat sink and each of the three terminals. This makes a total of six tests, with two readings taken for each test.

Some digital ohmmeters cannot be used to test diodes in the rectifier bridge. Consult the ohmmeter manufacturer to determine your ohmmeter capabilities.

Scheme 9

Regulator

The regulator cannot be tested outside of the Generator. If the rotor, stator, and rectifier bridge are OK, but the generator still produces more than 16 volts or does not produce within 15 amperes of the rated output during a generator output test, replace the regulator.

Assembly

Assemble two locators from the brush holder with needle nose pliers or side cutters.

1. File the jagged edges down to the level of the surrounding material. Keep loose particles away from the brush slots.
2. Blow away any dust.

Installation

1. Install terminal insulator to the outside of the slip ring end frame.
2. Install BAT terminal to the rectifier bridge with a washer and nut.
3. Install rectifier bridge into the end frame.
4. Install capacitor. Make sure the side with the insulator material is placed against the end frame (ground).
5. Install two bolts through the rectifier bridge.
6. Install two insulated screws through the rectifier bridge. If the brush holder, regulator, or connector has been replaced, connect it by crimping the connectors to the other components. Solder the connection using as little heat as possible to avoid heat damage to the regulator. see scheme 10
7. Install brushes into the brush holder. If the brushes are being reused, be sure they are clean. Wipe them with a clean, dry cloth. Retract the brushes in the holder. Retain the retracted brushes with a retaining pin. Make sure the pin extends through the end frame when the brush holder is in place. After the rotor and drive end frame are installed, the pin will be pulled out, allowing the brushes to contact the slip rings.
8. Install brush holder, regulator and connector assembly into the end frame. see scheme 8 The metal side of the capacitor strap should rest against the regulator connection.
9. Install one bolt into the brush holder. If a brush holder with locator bosses is being replaced with a holder without locators, make sure to align the brush holder assembly and hold it with your fingers while tightening the brush holder attaching screw.
10. Install two insulated screws through the regulator connector.
11. Install stator into the end frame, aligning the three stator leads to the three rectifier bridge terminals. see scheme 14
12. Install three rectifier bridge nuts. Tighten the nuts securely.

1. Install drive end bearing into the frame. (Scheme 8) Press against the outer race to press the bearing into place.
2. Install retainer with three screws. NOTE: On models with a slip ring end ball bearing on the rotor shaft, this bearing must be replaced with a new bearing any time the two halves of the generator are separated. If not replaced, the bearing may bind and fail due to distortion of its outer tolerance rings. This does not apply to roller-type slip ring end frame bearings.
3. Install new slip ring end bearing onto the rotor shaft or into the drive end housing. see scheme 15 Press against the inner race (bearings on the rotor shaft) or the outer race (bearings in the drive end housing) until the stop is reached.
4. Install rotor shaft through the inside collar and through the end frame.
5. Install outside collar, fan, and fan collar, onto the shaft. (Scheme 8)
6. Install pulley, washer, and pulley nut onto the shaft. Tighten pulley nut to 75 Ft. lbs. (100 N.m).

MAIN ASSEMBLY

1. Assemble drive end frame and rotor assembly to the slip ring end frame, lining up the marks. If the slip ring end bearing is on the rotor shaft, follow these steps: Carefully guide the slip ring end bearing into the slip ring end frame. Make sure the tolerance rings on the bearing outer race are not damaged.
2. Assemble Four through-bolts. Tighten securely. Remove the brush retainer from the end frame. Test the generator output.

GENERATOR SPECIFICATIONS

TORQUE SPECIFICATIONS

Pulley Nut - 74 Ft. lbs. (100 N.m)

See also:
• SPECIFICATIONS