SAE J180:2019 pdf free

SAE J180:2019 pdf free.Electrical Charging Systems for Off-Road Work Machines
Normal charging system operation includes an alternator that generates electrical energy from a mechanical source, a voltage regulator to control the alternator output voltage, and a battery that provides a standby source of electrical energy.Further information on voltage regulators is found in SAE J2669, and on battery specifications is found in SAE J537 and SAE J930.
Batteryless operation occurs in a machine application whenever the battery becomes disconnected from the alternator. The electrical load of the alternator is significantly different in this situation. The disconnection may be intentional or unintentional.In some applications, machines are shipped for export without batteries. In this situation, a slave battery may be used for jump starting the machine. After the machine is started, the battery is disconnected, and the machine is moved. During movement, the alternator is operating without the battery and expected to power such items as the engine control unit,transmission control unit, and engine fuel solenoids.
Reverse polarity occurs when the battery positive and negative cables are hooked up in reverse. This condition normally results in damage to the alternator and to any other semiconductor loads that experience the reverse polarity hookup.
A sudden interruption of most electrical loads from the alternator during alternator operation causes a self-induced voltage surge named load dump. Load dump could be caused by such items as connections to the alternator B+ terminal becoming loose, connections to the alternator B+ terminal being corroded, defective alternator output cables, etc. The effect of a load dump is the presence of voltage spikes significantly exceeding system voltage and may exceed the voltage breakdown limits of some electrical components to cause damage.
Most engine-driven alternators have a wide operating speed range and electrical loads may range between very low amperage to its maximum rated amperage. Over such a wide operating envelope, the alternator efficiency varies significantly between a peak efficiency and much lower efficiency. Average alternator efficiency takes into account alternator efficiency at several operating speeds at a fixed electrical load proportional to the alternator output rating.SAE J180 pdf free download.