Installation Manual

Electrical & Electronic Application And Installation Manual
Production Release Version 1.0
Page 125
in series with the ignition keyswitch input to provide a remote stop feature. It
is recommended that the switch is a latched contact type as closing the switch
whilst the engine is shutting down could cause the engine to restart.
In the event of Delayed Engine shutdown being activated as a protection
feature on the 1206F product range a 4 position key switch is recommended.
A 4 position key switch will be used to provide the following functionality;
• Ignition OFF
• Ignition ON
• Crank
• Delayed Engine Shutdown Override.
The delayed engine shutdown override position of the key switch must be
wired via a relay back to the User Defined Shutdown J1 input. More
information on the installation of the keyswitch and interaction with DES can
be found in section 16.3.
10.2.2 Battery Isolation Switches
Battery Isolation switches are usually fitted in the battery or the engine
compartment of a machine. On some machines there may be a small number
of low current devices which are not switched off by this device e.g. clocks or
anti-theft tracking devices.
The function of a battery isolation switch is as follows:
• Prevent battery discharge during vehicle shipping or storage
• Protect service technicians from danger caused by inadvertent engine
crank or start .To offer good protection of service personnel is it
possible to provide a switch which can be locked in the open position
(e.g. with a padlock) and the key removed and given to the service
engineer who is working on the dangerous components
The battery isolation switch is not a suitable method for stopping an engine,
as it is not guaranteed to stop the engine as the ECM may continue to operate
with power generated by the alternator.
It is also possible that opening the battery isolation switch when the engine is
running will cause an “alternator load dump”. This is a kind of electrical
transient that can cause damage to electronic components
Battery isolation switches are normally fitted in the negative path, close to the
battery.