SHUTOFF AND ALARM SYSTEMS COMPONENTS
SYSTEMS OPERATION
element feels the temperature of the coolant and then
operates the micro switch in the contact when the
coolant temperature is too high, the element must be in
contact with the coolant to operate correctly. If the cause
for the engine being too hot is because of low coolant
level or no coolant, the contactor switch will not operate.
The contactor switch is connected to the rack shutoff
solenoid to stop the engine. The switch can also be
connected to an alarm system. When the temperature of
the coolant lowers to the operating range, the contactor
switch opens automatically.
WATER TEMPERATURE CONTACTOR SWITCH
CIRCUIT BREAKER
The circuit breaker gives protection to an electrical
circuit. Circuit breakers are rated as to how much current
they will permit to flow. If the current in a circuit gets too
high it will cause heat in disc (3).
Heat will cause distortion of the disc and contacts (2) will
open. No current will flow in the circuit.
CIRCUIT BREAKER SCHEMATIC
1. Disc In open position. 2. Contacs 3. Disc. 4, Circuit
terminals.
NOTICE Find and correct the problem that caused
the circuit breaker to open. This will help prevent
damage to the circuit components from too much
current.
An
open
circuit
breaker
will
close
(reset)
automatically when it becomes cooler.
MECHANICAL OVERSPEED SWITCH
The overspeed switch is installed on the tachometer
drive shaft on the fuel injection pump. The switch
activates when the engine speed is equal to the
overspeed setting. When the overspeed switch has
activated, the contacts do not automatically return to their
normal positions. The reset button (I) must be pushed by
the operator to make the switch contacts return to their
normal positions. The usual setting for the overspeed
switch is 18/% higher than the rated speed of the engine.
MECHANICAL OVERSPEED SWITCH
1. Button.
Some overspeed switches
also
have
underspeed
contacts. These contacts close at approximately 600 rpm
as the engine speed increases. The underspeed setting
is not adjustable.
ELECTRONIC SPEED SWITCH
The electronic speed switch (dual speed switch)
activates the shutoff solenoid when the engine speed
gets approximately 18% higher than the rated full load
speed of the engine. It also stops current flow to the
starter motor after the engine starts.
MAGNETIC PICKUP INSTALLED
44
