Introduction

Speed monitoring is best done by addressing the actual road speed of the vehicle, not by limiting engine revolutions which correspond to the desired road speed in top gear. This creates havoc as it prevents the engine from being revved to its maximum design limit through the gears. Downward gear changes can drop engine revolutions to well below peak torque and cause unnecessary lugging.

The Safestop Speed Limiter uses an independent signal system to establish the actual road speed of the vehicle which allows full transmission and revolution utilisation.

What's in the box

Cab equipment consists of an epoxy encapsulated control module, dedicated wiring harness, high frequency Piezo buzzer, fuel valve and fittings and a gearbox transducer.

Function

Speed is controlled by temporarily closing the fuel supply to the injector pump for the duration of the time spent above the speed set point. Road speed must fall 5% below the set point before the fuel supply to the injector pump is restored.

Road safety is addressed by initiating a warning to the driver that the set speed is being reached. This warning is in the form of the high frequency buzzer which turns on at 5% below the throttle collapse speed.

Operation

The system revolves around the control of a fuel solenoid which is installed between the fuel filter and the injector pump. This valve receives its instructions from the Electronic Control Module. Impulses relative to road speed are generated by a gearbox transducer.

As impulses from the transducer reach a predetermined point the alarm buzzer is activated. A further 5% increase of impulses causes the Control Module to deny power to the fuel solenoid which then closes off the fuel supply to the injector pump. After a short delay the engine loses power due to fuel starvation.

This condition continues for as long as impulses are above the pre-set point. Only when impulses drop 5% below this point does the fuel solenoid respond by re-opening and again allowing fuel to pass to the injector pump, thus restoring power to the engine.

Please note that during the period when the fuel valve is closed, all functions such as brakes and steering continue to work as the engine is still being turned by the traction wheels.

Example

Assume road speed is set at 85 km/h.

This would automatically sound the warning buzzer at 81 km/h. Below 81 km/h the vehicle behaves normally. As speed reaches 81 km/h the warning buzzer sounds and will continue to do so for as long as speed remains above this point. If speed continues to increase, at 85 km/h the fuel valve closes. A brief delay follows. Loss of power due to fuel starvation causes deceleration. As road speed falls below 81 km/h the buzzer turns off and the fuel valve re-opens which restores power to the engine.

Features

• Encapsulated Electronics
• Pre-Warning Before Power Loss
• Fully Adjustable
• Dedicated Wiring Harness
• Tamper Proof Control Module
• Water Proof Electronics
• Vibration Proof Electronics
• No Maintenance Required
• Availability And Service Nationwide
• Suitable For All Diesel Powered Vehicles