BMW 7_ая the E38 series from 1994 to 2002
1. Introduction
2. Governing bodies and operation receptions
3. Settings and routine maintenance of the car
4. Engine
5. Systems of cooling of the engine, heating, ventilation and air conditioning
6. A power supply system and production of the fulfilled gases
7. Systems of electric equipment of the engine
7.1. Systems of ignition, preheat and engine management
7.2. Charge and start systems
7.2.1. General information
7.2.2. The storage battery - the general information, recommendations about service
7.2.3. Charge system - general information and security measures
7.2.4. Removal and generator installation
7.2.5. Replacement of a regulator of tension
7.2.6. System of start of the engine - the general information and precautionary measures
7.2.7. Removal and starter installation
7.2.8. Replacement of the traction relay
8. Manual box of gear shifting and coupling
9. Automatic transmission
10. Kardanny and power shafts, reducer, differential and stupichny assemblies
11. Brake system
12. Suspension bracket and steering
13. Body
14. Onboard electric equipment
15. Electric equipment schemes



7.2.3. Charge system - general information and security measures

On considered cars the generator of an alternating current is used. At installation of additional electric equipment check, that capacities of the generator was enough for providing new consumers with the electric power.

The drive of the generator is carried out by a belt from a cranked shaft of the engine.

The generator represents the three-phase synchronous electric car with electromagnetic excitement. For transformation of an alternating current in constant the diode rectifier is built in the generator. Adjustment of target tension is carried out by the built-in regulator. The generator has grounding on weight.

At operation of the generator the electric current proceeding on a winding of excitement, creates a magnetic stream round rotor poles. At rotation of a rotor there is a periodic change of its magnetic poles under each tooth of a stator, as a result, the magnetic stream passing through teeth, continuously changes on size and tension. This variable magnetic stream creates an electromotive power (EDS) in a stator winding. The wedge-shaped form of polar tips of a rotor is picked up in such a manner that allows to receive close to sinusoidal a form of curve EDS.

At high frequency of rotation of a rotor when target tension of the generator starts to exceed 13.6 ÷ 14.6 In, the regulator of tension is locked, and the current does not pass through a winding of excitement. When tension decreases, the regulator opens again, providing freedom of a transmission of a current through an excitement winding. The frequency of rotation of a rotor, the more long a regulator is higher remains locked and, that respectively tension on a generator exit more strongly decreases. Process of locking and unlocking of a regulator occurs to high frequency therefore target fluctuations remain almost imperceptible and it is possible to consider tension of the generator to the constants supported at level of 14.4 Century.

The system of a charging does not demand periodic service, however check of a condition and replacement of a driving belt of the generator, the storage battery and its electroconducting it is necessary to make on a regular basis according to the schedule THAT (see. Sections Check of a condition of the battery and care of it and Check of a condition of a belt of a drive of auxiliary units of Head of Control and routine maintenance of the car).

At ignition inclusion on a combination of devices should light up quickly To/l a charge (see. Head Governing bodies and operation receptions). If the lamp is not disconnected after start of the engine or lights up in the course of its functioning, check a condition of components of system of a charge. Refusal of activation of a lamp at inclusion of ignition testifies to its exit out of operation, damage of the corresponding electroconducting, or violation of serviceability of functioning of the generator (including break of a driving belt).

Security measures at generator service

  • Do not disconnect the battery or a tension regulator at the working engine;
  • Do not close on weight the plug of excitement of the generator or the cable fixed on it;
  • Do not confuse an order of connection of electroconducting of a regulator of tension;
  • Remember that inclusion of the regulator of tension closed on mass leads to an instant exit it out of operation;
  • Never remove the generator at the connected battery;
  • Do not confuse polarity of connection of the storage battery;
  • Never use at checks of onboard electric equipment the tension or lamp samplers measuring instruments connected to a household network (110/220 In);
  • At check of a condition of diodes do not submit on them tension more than 12 In and do not apply мегомметры, also having high target voltage, - breakdown of diodes will lead to short circuit. Remember that at check of isolation of electroconducting with the help мегомметра it is necessary to disconnect all electroconducting from the generator;
  • At a charging of the storage battery without removal it from the car track, that both wires were disconnected from it. Do not confuse polarity of connection of the charger;
  • Before carrying out on the car of any electrowelding works do not forget to disconnect electroconducting from the generator and the storage battery;
  • Any checks of chains and knots of onboard electroconducting make at the idle engine and the disconnected storage battery;
  • Remember that violation of polarity of any connections is interfaced to risk of irreversible failure of the rectifier and a regulator of tension of the generator.

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7.2.2. The storage battery - the general information, recommendations about service
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7.2.4. Removal and generator installation