Keywords: ISO 7638, ebs, abs, safety, coupling
'EBS-Safe' is a unique Don-Bur warning system that ensures a compliant ISO 7638 ABS/EBS (often known more simply as EBS) connection.
Why is it so important?
A valid EBS connection is a legal requirement for good reason. It provides power to the ECU (the trailer's brain) and critical 'CAN' data which control the following:
- Roll Stability (RSS) - for the prevention of roll-over
- ABS - to prevent wheel locking during braking
- LSV - (Load Sensing Valve) for the correct proportional braking pressure relative to load weight
- Braking response time - The EBS lead provides a faster braking reaction time from the time the driver applies pressure to the foot pedal and the time the brakes activate.
- Suspension - for the correct suspension ride height and therefore correct overall trailer height
What can go wrong?
Don-Bur recently became aware that the incidence of a failed EBS connection in transit was higher than previously imagined. The trait was originally discovered via a thorough investigation within a blue chip fleet (using multiple carriers) with detailed telematics data which highlighted a rate of 36.5 incidents per week over a given period where the EBS connection was either faulty or non-existent.
There are a number of reasons why a valid EBS connection might not be present:
1) Most simply, the driver may not have connected it.
2) The cab EBS fuse may have blown.
3) The EBS wiring/connections may be old or damaged with extended use.
4) Lastly, because of the similarity between the tractor plug connection and the plug that is stowed in the dummy socket holder (for the loose end that is supposed to be connected to the trailer), the driver may be grasping the wrong end from the back of the tractor and connecting it to the trailer. It will look right but has no power.
Regrettably, there are a number of routes to failure.
What are the consequences?
Whilst this might not sound too alarming at first, the lack of a valid EBS connection significantly increases the risk of roll-overs, jack-knifing, poor braking distances, aquaplaning and bridge strike (particularly for high double decks). If an accident is proven to be as a result of the lack of an EBS connection, the operator/driver may be held liable for damages or, in the worst case where the accident results in a death, manslaughter.
Consider the implications of a double deck trailer fitted with high lift suspension (+240mm) and only a few inches of clearance under bridges at ride height. If the suspension doesn't re-set correctly to ride height (which requires an EBS connection) after being loaded/unloaded, a trailer's height in transit could easily exceed a 16' 6" (5.029m) unmarked bridge height.
If a valid EBS connection is not present, the 'EBS-Safe' system will warn the driver via a 90bD siren and a warning light on the front bulkhead. The light is placed at a height and position to match the view in the driver’s mirror. Once the EBS connection is made, the warnings stop and the ABS/EBS functions start operating correctly again.
It does not require independent batteries and can be quite easily retro-fitted.
EBS-Safe provides operators with the peace of mind that their drivers are coupling up the ISO 7638 ABS/EBS line correctly. It enforces compliance and ensures that all critical safety systems are functioning correctly.
A Patent for EBS-Safe has been applied for.