Description - jcb JS300 Service Manual

Overview
W
R
Fig 1. Connector Posts (C042)
Alternator Harness Connections
Pins Details
R To ignition relay C033 (24V)
L Alternator output voltage
B+ Battery voltage (24V)
When the starter key is set to position I a 24V supply
connects to the alternator at terminal R. The voltage
provides a field current to the alternator windings via the
voltage regulator.
When the engine is running the output from the trio diode
rectifier is fed to regulator which now provides the field
current.
Important: Although the alternator circuit is self sustaining
once the engine is running, do not disconnect or isolate the
batteries. Disconnection or isolation of the batteries while
the engine is running can cause severe damage to the
machine electrical systems.
The regulator changes the field current depending on the
load from the machine electrical system.
C-147

Description

L
B+
C128790
9813/5100-1
Section C - Electrics
Power from the alternator is fed into the machine circuits
and to charge the batteries via primary fuse B.
The L terminal is connected to the MECU (C025) which
monitors the voltage output from the alternator (C042).
The MECU broadcasts the value of the voltage output on
the CANbus. If the voltage is too high or too low the MECU
broadcasts a fault code on the CANbus. The charging
voltage is displayed on the display monitor in the machine
status menu.
Charging System
Description
C-147