13.3. System of power supply

General information and precautionary measures
The system of power supply consists of the generator, the regulator of tension and the rechargeable battery. At collaboration of these devices food of such consumers of the electric power as elements of ignition, a headlight, the radio receiver, etc. is provided.
Generators of alternating current are installed on cars.
At installation of additional electric equipment check that there was enough power of the generator for power supply of this equipment. Basic elements
the generator the rotor, the stator, the rectifier, collector brushes, the electronic regulator of tension, bearings and a pulley of a belt are.
The drive of the generator is carried out by a belt from a bent shaft of the engine.
The generator represents the three-phase synchronous electrical machine with electromagnetic excitement. For transformation of alternating current in constant the rectifier on diodes is built in the generator.
Tension is regulated by the built-in electronic regulator of tension.
During the operation of the generator the electric current proceeding on an excitement winding creates a magnetic flux around rotor poles. At rotation of a rotor under each tooth of the stator passes the southern, northern poles of a rotor – the working magnetic flux passing through stator teeth changes in size and tension. The variable magnetic flux creates the electromotive force in a stator winding. The wedge-shaped form of polar tips of a rotor is picked up in such a way that allows to receive the form of curve electromotive force close to sinusoidal.
With a high frequency of rotation of a rotor
the generator when tension of the generator becomes more than 13,6-14,6 In, the regulator of tension is locked and current does not pass through a winding of excitement. Tension of the generator falls, the regulator opens and again passes current through an excitement winding. The frequency of rotation of a rotor of the generator is higher, the time of the locked condition of the regulator is more, therefore, the stronger tension at the generator exit decreases. Process of locking and unlocking of the regulator happens with high frequency therefore fluctuations of tension at the exit of the generator are imperceptible, the constants supported at the level of 13,6–14,6 Century can almost consider it.
When checking the generator, and also at operation of the car it is necessary to follow a number of rules not to put the generator out of action:
– not to allow operation of the generator with the rechargeable battery disconnected from a generator clip. Without rechargeable battery in onboard network of the car there are dangerous impulses of an overstrain at shutdown of any consumers of the electric power. This pulse an overstrain can put the electronic equipment of the car, including the regulator of tension and diodes of the vypryamitelny block of the generator out of action;
– not to check operability of the generator for a spark even short-term connection of a "plus" clip of the generator with "weight". In this case via diodes considerable current proceeds and they are damaged. It is possible to control generator tension only the voltmeter;
– the negative plug of the rechargeable battery always needs to be connected to "mass" of the car, and positive – to a generator clip. Wrong (return) turning on of the battery will immediately cause passing of the raised current via generator diodes, and they will fail;
– not to check diodes more than 12 V or the megohm meter as its tension, too high for diodes, and they when checking will be punched (there will be a short circuit). When checking isolation of an electrical wiring the megohm meter it is necessary to disconnect all wires from the generator;
– at electric welding of any details of a body it is necessary to disconnect all wires from the generator and the rechargeable battery;
– to check chains and knots of electric equipment and to eliminate malfunctions it is necessary at the idle engine and the disconnected rechargeable battery.

Check
With malfunction in a chain of charging of the rechargeable battery check the following:
– reliability of fastening of power wires to plugs of the rechargeable battery (be convinced of their purity and reliability of fastening);
– electrolyte density in the rechargeable battery (if density low, charge the battery);
– electrical wiring of the generator and reliability of its fastening;
– state and tension of a belt of the drive of the generator;
– inhaling of a bolt of fastening of the generator;
– the noise listened from the generator after launch of the engine.
At the switched-off ignition check the voltmeter tension on battery plugs, having connected it to a conclusion "In" the generator. Tension has to be about 12 Century.

PREVENTION
When checking the generator it is not allowed to connect to "weight" a conclusion of "L" at the working engine or to launch the engine at the disconnected wires from conclusions of "L" and "R".


Fig. 13.4. Electric circuits for check of the generator (A) and the regulator of tension (In):
1 – voltmeter; 2 – relay of inclusion of a control lamp of charging of the rechargeable battery; 3 – control lamp of charging of the rechargeable battery; 4 – ignition switch; 5 – ampermeter


For check of system of charging collect a chain according to fig. 13.4. At the switched-off ignition check tension between "weight" and a conclusion of the "L" generator. If the voltmeter does not show tension, so the generator is faulty. Turn a key in the ignition switch in the provision of "ON" and check tension. If the voltmeter does not show tension, so the generator or wires are faulty. If tension is close to the battery tension (12 V), connect a conclusion of "F" to a back arm of the generator and check tension. If tension shown by the voltmeter, less than 12 V tension regulator is faulty. For check of tension of the regulator without loading be convinced that the rechargeable battery is charged completely, connect the ampermeter and the voltmeter according to the scheme in fig. 13.4. At the switched-off ignition tension shown by the voltmeter has to be equal to zero.
Include ignition, at the same time the indication of the voltmeter has to be 1-3 V lower than tension on plugs of the rechargeable battery. If the indication of the voltmeter equally in tension on plugs of the rechargeable battery, so the generator is faulty. Close ampermeter conclusions a crossing point, launch the engine and remove a crossing point.

PREVENTION
Before launch of the engine be convinced that the ampermeter is not switched on in a starter power-supply circuit.

Increase the frequency of rotation of a bent shaft of the engine up to 2500 min.-1 and take readings of the ampermeter and the voltmeter. The current shown by the ampermeter has to be equal 5 A, tension – (14,7±0,3) B (at a temperature of 20 °C).

Fig. 13.5. The electric circuit for the check of tension and current developed by the generator: 1 – L plug; 2 – plug "B"


For the check of current and tension developed by the generator disconnect a wire from the negative plug of the rechargeable battery and connect the ampermeter and the voltmeter according to the scheme provided on fig. 13.5.
Connect a wire to the negative plug of the rechargeable battery, launch the engine and include headlights. Gradually increase the frequency of rotation of a bent shaft of the engine and you monitor indications of the voltmeter. The system of charging is serviceable if tension exceeds tension of the rechargeable battery and the ampermeter shows the proceeding current.

Generator

Technical characteristic of the generator
Rated voltage, In
12
Nominal current, And
65
The output tension of the regulator, In
14,7±0,3
Length of brushes, mm:
nominal
minimum admissible

18
8
Nominal resistance, Ohm
3-4

Removal and installation
Disconnect a wire from the negative plug of the rechargeable battery.

Fig. 13.6. Elements of fastening of the generator:
1 – adjusting bolt; 2 – the conclusion socket "In";
3 – socket of conclusions "L" and "R"; 4 – coupling bolt and nut; 5 – generator drive belt


Turn off an adjusting bolt (fig. 13.6).
Disconnect sockets and release wires from a collar.
Take off a generator drive belt.
Turn off a nut of a bolt of fastening of the generator and remove the generator.
Install the generator and screw a nut on a coupling bolt. Screw an adjusting bolt.
Establish a belt of the drive of the generator and adjust its tension.
Connect sockets to the generator.
Connect a wire to the negative plug of the rechargeable battery.

PREVENTION
When replacing brushes it is necessary to use a soldering iron. Certain skills of the soldering are necessary for performance of work.

Replacement of brushes
Remove the generator.
Turn out three screws of fastening of a back cover of the generator.

Fig. 13.7. Place of heating by a soldering iron of a back cover of the generator


The 200 W soldering iron heat a back cover with the bearing case within 3–4 min. or blow hot air in more long time (fig. 13.7). In conclusion it is necessary to heat the bearing case to temperature of 50-60 °C without heating of other details.
Without allowing to cool down a back cover, remove a forward cover with a rotor, having inserted a screw-driver edge between a forward cover and the core of the stator. Be careful not to damage a stator winding. Make sure that the lock ring of a back cover is in the place. Clear contact rings of a rotor the soft rags which are slightly moistened in solvent.
Turn out the screw of a plate of fastening of the regulator of tension and the brush holder. Turn off a nut of fastening of a conclusion "In", remove a washer.
For release of a plate of the regulator of tension unsolder connecting wires from the rectifier. The soldering should be expedited that because of an overheat the rectifier did not fail.

Fig. 13.8. Control size of a brush of the generator: And =2–3 mm


Take a plate of the regulator of tension and the brush holder. Unsolder old brushes and solder new. After installation of new brushes the control line of extreme wear on them has to be at distance of 2-3 mm from a contour of the brush holder (fig. 13.8).
Establish a plate of the regulator of tension and solder connecting wires. Establish a washer and screw a nut of fastening of a conclusion "In".
Carefully press brushes, record their situation a thin core or a drill, having inserted it through an opening in a back cover. Special openings which the clamp enters are provided in new brushes.

Fig. 13.9. Arrangement of a lock ring of the back bearing


Make sure that the lock ring of the back bearing is in a flute of the bearing (fig. 13.9). Heat a cover of the back bearing as well as at removal, establish a rotor and a forward cover.
Screw three screws of fastening of covers.
Extend the clamp holding brushes in the taken-away situation.
Install the generator on the car.

PREVENTIONS
If the generator developed the resource, it is more expedient to establish new, than to repair old.
Before performance of repair work check existence in sale of spare parts and their cost. Repair requires a powerful soldering iron; besides, certain skills of work are necessary.

Repair of the generator with full dismantling
Remove the generator from the car.

Fig. 13.10. Generator: 1 – nut and washer of fastening of a pulley; 2 – screw; 3 – a forward cover (from the drive), the bearing and a restrictive washer; 4 – rotor and back bearing; 5 – rectifier; 6 – plate of the regulator of tension and brush holders; 7 – a back cover with the bearing case; 8 – stator


Turn off a nut of fastening of a pulley and remove a washer (fig. 13.10). During a nut otvorachivaniye for fixing of a pulley from a provorachivaniye squeeze a bracket an old belt of the drive.
Remove a pulley, a krylchatka (if the krylchatka is installed separately on a shaft), the remote plug and a dish-shaped washer.
Turn out three screws of fastening of a back cover of the generator.
The 200 W soldering iron heat a back cover with the bearing case within 3–4 min. or an obduyta hot air more long time (see fig. 13.7). In conclusion it is necessary to heat the bearing case to temperature of 50-60 °C without heating of other details.
Without allowing to cool down a back cover, remove a forward cover with a rotor, having inserted a screw-driver edge between a forward cover and the core of the stator. Be careful not to damage a stator winding.
Easy percussion beat out a rotor from the forward bearing.
Turn off a nut of fastening of a conclusion "In" and remove a washer. Turn out three screws of fastening of the rectifier, a plate of the regulator and the brush holder from a back cover. Take the stator, the rectifier and other details from a cover.
If electric tests of the stator or rectifier are carried out, unsolder conclusions and separate them from each other. Note an arrangement of conclusions not to mix them at assembly. You carry out the soldering quickly that because of an overheat the rectifier did not fail.
Replace collector brushes.

Fig. 13.11. Use of an ohmmeter for check of conductivity of windings of the stator


Ohmmeter or consistently included a lamp on 12 V and the power supply check stator windings for existence of breaks (fig. 13.11). Between any couple of conclusions there has to be a conductivity.

Fig. 13.12. Use of an ohmmeter for check of conductivity between the coil and the core of the stator


Check short circuit of the coil of the stator for the core. Make sure that between the coil and the core there is no conductivity, otherwise replace the stator (fig. 13.12).
Check a generator rotor for existence of damages, especially attentively examine contact rings of a collector. Traces of an insignificant podgoraniye can be eliminated with grinding by a fine-grained emery paper, then wipe with the soft fabric which is slightly moistened with solvent. Strongly worn-out rotor is subject to replacement.

Fig. 13.13. Use of an ohmmeter for check of conductivity between contact rings of a rotor


Check the rotor coil. Make sure that between contact rings there is a conductivity (fig. 13.13). If resistance too low, so short circuit in the coil. If conductivity is absent or there is a short circuit, replace a rotor.

Fig. 13.14. Use of an ohmmeter for check of conductivity between a contact ring of a rotor and an anchor


Check short circuit of the coil of a rotor for an anchor. Make sure that there is no conductivity between a contact ring and an anchor of a rotor (fig. 13.14). If conductivity is, replace a rotor.
Check free rotation and existence of a side play in rotor bearings. If the condition of bearings raises doubts, replace them. Be convinced of correctness of installation of the bearing of a rotor from a collector (the flute under a lock ring has to be directed towards contact rings).
Check conductivity of three diodes, having connected ohmmeter probes to both ends of each diode. Conductivity has to be only in one direction.
If conductivity in two directions is found, so the diode is punched, the rectifier needs to be replaced.
Assembly of the generator should be begun with the soldering of conclusions of a plate of the regulator, the stator and the rectifier.
Establish the soldered details in a back cover and fix by screws, having established a washer and having wrapped a nut of fastening of a conclusion "In".
Carefully press brushes, record their situation a thin core or a drill, having inserted it through an opening in a back cover. Special openings which the clamp enters are provided in new brushes.
Make sure that the lock ring of the back bearing is in a bearing flute (see fig. 13.9). Heat a cover of the back bearing the same as at removal, and establish a rotor.
Establish a dish-shaped washer on a rotor shaft, having convinced of its correct orientation.
Establish a forward cover over a rotor and easy blows besiege it into place. Screw three screws of fastening of covers.
Establish the second dish-shaped washer, the remote plug, a krylchatka and a pulley. Pull together with a bracket a driving belt, establish a washer and screw a nut.
Extend the clamp holding brushes in the taken-away situation, then install the generator on the car.

Rechargeable battery
The rechargeable battery is intended for launch of the engine and food of consumers at the idle engine when the generator does not develop the electric power.

PREVENTION
You watch that the case of the rechargeable battery had no cracks and leakages of electrolyte. For protection of skin of hands against electrolyte at removal of the rechargeable battery use special rubber gloves (not household).

The rechargeable battery is located in a forward part of a motor compartment. Fastening of the battery is provided with the clamping bracket covering all case of the battery.
Disconnect wires from plugs of the rechargeable battery, since the negative plug.
Turn off nuts and remove a bracket of fastening of the battery.
Carefully take the battery from a motor compartment.
Do not overturn the battery at all. The spilled electrolyte should be washed away immediately a large amount of water. For protection of skin of hands against electrolyte it is necessary to watch that the case of the rechargeable battery had no cracks and leakages of electrolyte. At removal of a battery room
batteries use rubber gloves (not household) and goggles.

PREVENTIONS
At charging of the rechargeable battery under a cover of each element explosive gas is formed.
You do not smoke near the charged rechargeable battery or the battery which was recently charged. Disconnect wires from plugs of the charged rechargeable battery only after switching off of the charger as in places of disconnection of a chain under loading there will be a spark. You hold the battery with open traffic jams far away from fire.

Check an arm of the rechargeable battery for existence of the damages caused by leak of electrolyte from the battery. Otherwise clear a surface a rigid brush and wipe the rag moistened in solution of baking soda in clear, warm water.
Wipe with the same solution the top part of the rechargeable battery.
Check the case and a cover of the accumulator for existence of cracks, if necessary replace the battery.
Clear plugs of the rechargeable battery the corresponding cleaner.
Clear an internal surface of clips of plugs, using for this purpose the corresponding tool. Replace the damaged or old wires and which became useless clips.
Installation is carried out to the sequences, the return to removal, taking into account the following.
Tighten nuts of fastening of the battery, without using too great efforts not to damage the case.
Connect wires to plugs of the rechargeable battery, having convinced that the top part of clips of wires is flush with the top part of plugs.
Reliably tighten clips of fastening of wires.
After that apply a layer of mineral lubricant on all connections. Internal surfaces of clips of wires and the contact surfaces of plugs of the rechargeable battery cannot be greased, otherwise violation of contact between clips of wires and plugs is possible.
Check of power wires
Periodically check each power wire. On all length of a wire there have to be no mechanical damages, a burn-out or cracking of isolation and traces of corrosion. Because of an unsatisfactory condition of connections of wires launch of the engine is at a loss.
Check a condition of clips of wires. Cracks, weakening of fastening of a clip and corrosion are not allowed. The raid of white color under isolation in a wire junction with a clip demonstrates corrosion of a wire and need of its replacement. Check existence of deformations of clips, an integrity of a carving of a nut and a bolt of fastening of a clip, corrosion traces.
If it is necessary to replace only the wire connected to the positive plug of the rechargeable battery at first disconnect a wire from the negative plug of the battery.
Disconnect a wire and remove it from the car. Make sure that length and diameter of a new wire precisely coincide with length and diameter of the replaced wire. Remove with a metal brush a rust from threaded connections with a starter or "weight". For simplification of installation and prevention of corrosion apply a thin film of technical vaseline on a carving. As often as possible check connections, tighten them and you keep clean.
Attach a wire to a starter or "weight", reliably tighten nuts.
Before accession to the battery of a new wire be convinced that it has sufficient length and it will be established without tension.
At first attach a wire to the positive plug of the rechargeable battery, then to the negative plug.
Check of the rechargeable battery
Check the rechargeable battery for existence of damages, such as cracks and the broken case or a cover which can lead to electrolyte leak. Define the damage reason, if necessary eliminate it or replace the battery. Remove corrosion traces with soda solution in water.
Check the specific density of electrolyte, at the same time enter the amendment of density depending on electrolyte temperature.
If electrolyte density less than 1,100 g/cm3, slowly charge the rechargeable battery with current 5 A during no more than 14 h, then check the battery under loading.
If density of electrolyte is in limits of 1,100-1,220 g/cm3, recharge the rechargeable battery.
If electrolyte density more than 1,220 g/cm3, check the battery under loading.
For check of the battery under loading discharge the battery current of a discharge 200 A during 15 with, then check tension on battery plugs.
If tension more than 9,6 In, the rechargeable battery is serviceable and it can be used.
If tension is in limits 9,6-6,5 B, do bystry battery charging, then check it under loading.

PREVENTION
If after repeated charging tension of the battery is still less than 9,6 In, it needs to be replaced.

If tension less than 6,5 In, the battery is faulty and it needs to be replaced.
Check of density of electrolyte
The specific density of electrolyte of the rechargeable battery changes together with temperature. Temperature increase of electrolyte leads to reduction of its density and vice versa, reduction of temperature leads to increase in its density.
Value of specific density of completely charged rechargeable battery has to be ranging from 1,260 to 1,280 g/cm3 at a temperature of electrolyte of 26,7 °C. The measured value of specific density should be corrected by addition 4 of points (0,004) for each 5,56 °C if temperature is above 26,7 °C, or subtraction of 4 points for each 5,56 °C if temperature is below 26,7 °C.
Never it is necessary to measure density right after water addition. Water and electrolyte should be mixed or by charging within several minutes at low current of charging, or endurance of the battery during 1 h.

PREVENTION
Density difference in 50 points (0,050) and more between one or more elements of the rechargeable battery indicates that the battery is faulty and it needs to be replaced.