LOFA EP250 Operation and Troubleshooting
463-3000-01 Rev C.1 - 28-Feb-2007
5
Oil Pressure LED (Red)
A solidly illuminated Oil Pressure LED indicates low oil pressure failure. The control system typically senses
low oil pressure from a ground contact switch on the engine. When a sender/switch combination is used on
the engine, the marking
WK
generally indicates the switch terminal. This input typically expects a normally
closed switch (ground contact when oil pressure is low). A defective switch or shorting the shutdown input to
ground can cause low pressure fault indication. Additionally, when using sender/switch combinations,
swapping the
WK
and
G
terminal can cause unintended shutdowns. The system can be configured for oil
pressure failure to indicate only.
Warning
Low oil pressure is not an indication of low oil level.
For best possible protection LOFA recommends using
our solid-state oil level shutdown switch.
Note
Most shutdown switches are grounded through the switch body.
Do not use insulating sealant (i.e. Teflon tape) when installing switches.
Temperature LED (Red)
A solidly illuminated Temperature LED indicates high engine temperature failure. The control system typically
senses high temperature from a ground contact switch on the engine. When a sender/switch combination is
used on the engine, the marking
WK
or
W
generally indicates the switch terminal. This input typically expects
a normally open switch (ground contact when engine temperature is too high). A defective switch or shorting
the shutdown input to ground can cause over temperature fault indication. Additionally, when using
sender/switch combinations, swapping the
WK
or
W
and
G
terminal can cause unintended shutdowns. The
system can be configured for temperature failure to indicate only.
Warning
If the temperature switch is not in contact with coolant due to
coolant loss the engine is not protected from overheating.
For best possible protection, LOFA recommends using
our solid-state coolant level shutdown switch.
Note
Most shutdown switches are grounded through the switch body.
Do not use insulating sealant (i.e. Teflon tape) when installing switches.
Some thermostat housings are composites and do not provide ground for the switch.
AUX 1 LED (Red)
A solidly illuminated AUX 1 LED indicates auxiliary 1 failure (i.e., coolant level, oil level, belt breakage,
hydraulic pressure, etc.). The control system typically senses failure using a ground contact switch. Auxiliary
inputs are equipment specific and determined by the equipment manufacturer. A defective switch or shorting
