312000854 - E1010 POWER SUPPLY SYSTEM - DESCRIPTION

DESCRIPTION

The entire electrical system is designed to increase the car''s safety level and prevent the possibility of fires and other consequences of electrical malfunctions. State-of-the-art connectors have also been introduced to rule out the possibility of many connection defects.Power is distributed via the junction units and/or fuse boxes located in the engine compartment and Body Computer under the dashboard. These are connected to control elements (relays and static actuators) to ensure maximum electrical protection and minimum wiring complexity.All wiring looms have been made modular (sub-assembly composition) by changing the way functions are distributed inside the connectors and replacing welds with short-circuiting joints.Two main types of protection are provided:

  • active protection, to reduce possible fault causes at source;
  • passive protection, to minimise the effects of a fault.
The first category covers careful design of wiring circuits, including well thought-out positioning and fastening and the definition of properly shielded and protected layouts.All operations designed to reduce or interrupt faulty currents (overloading or short circuits) are included in this type of passive protection.Details of the main safety solutions adopted are as follows:

  • power supplies protected by Maxifuses to cut off the electrical system in the event of short circuit;
  • the layout of the whole system is optimised to reduce the risk of damage in the event of faults or accidents;
  • wiring installation has been optimised to reduce incorrect positioning and noise due to vibrations;
  • all wires offer high resistance to abrasion;
  • the wires in the engine compartment are resistant to high temperatures and are protected with piping or sheaths;
  • wires in the passenger compartment are protected by corrugated pipes and felted tapes to reduce noise levels;
  • the main connections come with secondary lock terminals and lever locks or CPA to prevent terminal deformation.
All systems and electrical equipment are supplied by the battery at a voltage of 12V.The battery is, in turn, recharged by the alternator during engine operation.    See E5010 STARTING AND RECHARING The main power supply lines are protected by MAXIFUSES contained in the engine compartment junction unit.The engine compartment junction unit consists of two connectors: A and B. The control unit receives a direct battery supply via connector A. Connector B is connected to the cables coming from the various consumers via fastoms in the lower part of the control unit itself. The control unit is therefore an integral part of the front wiring.The Body Computer under the dashboard is connected via special multifunctional connectors in the various wires and protects the secondary load lines via dedicated fuses. A series of built-in relays operates these circuits.
The relays in the Body Computer are incorporated into the control unit itself; therefore no type of operation can be carried out (replacement, removal, etc.).
Some circuits are continuously supplied, even with the car at a standstill and the key out because they are connected directly to the battery.Other circuits are supplied by turning the ignition key to various positions:

  • when the ignition key is inserted and turned to the MAR position, numerous circuits are supplied - these are known as ignition-operated (INT and 15/54 lines with the power supply maintained even during starting and INT/A, whose power supply is interrupted during starting);
  • the second position - AVV (starting) - supplies the starter motor (line 50), disconnecting some other circuits (those which absorb a lot of power, INT/A line) thereby ensuring the maximum current flow to the starter motor.
The lines that distribute power to the various consumers are represented in the wiring diagrams for the various functions and systems.This general diagram shows all the power supply lines as they leave the battery, engine compartment junction unit and Body Computer. Refer to specific diagrams for more details.