For the flotilla of Australia’s successful road transport logistics companies, everything is about precision and timing; being able to deliver goods on time means having the right equipment and tools.
This means ensuring its trucks and trailers combinations are in perfect working order for the often-rugged conditions that logistics services face in Australia.
This is where many of the fleet operators have found one very crucial issue that was a growing concern in its road transport operations – power supply to the trailers’ emergency braking systems (TEBS).
In fact, it was so significant that it was becoming an industry-wide problem.
Since 2019, the emergency braking systems are mandatory for all trailers courtesy of the Australian Design Rules.
The problem arose when the power supply to the TEBS in some multi-combination vehicles was not sufficient when the drivers went into a full braking load.
Longer combinations and trailers, fitted advanced safety features, can overload the power converters feeding systems, such as the TEBS.
When a trailer of any length, whether a 53-metre or 55-metre combination, is using TEBS, the last trailer always needs to be above 13 volts to ensure the TEBS is working properly.
If the voltage hits eight volts or less, the TEBS will ‘brown out’ and become non-functional, leading to dangerous and possibly catastrophic scenarios.
“Some combinations can face issues due to the length of their trailers where in a 12-to-24-volt system not having sufficient power for the TEBS by the time it reaches it,” Eaton Group’s Mobility Area Sales Manager, Nick Hope, explains.
Naturally, such an occurrence is alarming and can be devastating when a fully loaded vehicle, in excess of 100 tonnes, reverts to ‘1:1 braking’ – whatever pressure the driver applies to the brake pedal is the same as the pressure going on the brakes and trailer.
This uncontrolled braking event can be catastrophic.
So, what do Australia’s premiere transport companies arrange to solve such a crucial issue? They turn to one of Australia’s largest suppliers of brake system components for commercial vehicles and trailers – the Eaton Group, which is renowned for providing the best safety technology and support to the commercial vehicle industry.
Eaton’s Nick Hope says that demonstrations of Eaton’s range of low converters at the 2025 Brisbane Truck Show convinced the clients that they need to test the hardware in ‘real world’ conditions as soon as possible.
Nick knew that Eaton’s trademark lightweight, low-voltage technologies could handle a challenging test, given the customisable equipment is designed to withstand harsh environments.
“We had identified a big hole in the market where there is a big issue with low voltage in the trailers, which our converters can address,” Nick explains.
“The opportunity for a trial was a golden opportunity for us to show what it could do, due to loads and vehicle combinations the clients use, which was a typical fleet size that faces low voltage concerns for the roll stability functionality and compliance.
“We looked at our DC converters and picked the 12-to-28-volt converter to both give more voltage to the rear trailer, but also for the current rating. The EBS needs a particular current rating as well, so the two go hand in hand.”
The solution was Eaton’s low voltage converter – a 12-28 Volt 40 Amp with CAN and ignition switch on-off mode. Simply known as Model Number 12040C12.
This small converter easily punched above its weight, and its modest name, to provide the client with the perfect answer to some mighty headaches.
Cloncurry trial
It wasn’t just a case of fitting the 12-28 volt converters and ‘she’ll be right, mate’.
The Eaton Group, and its distributor Airbrake Systems Pty Ltd, first had to put the converter through some truly rugged and challenging tests, where it was up against another brand of converter.
For a company that is one of the most visible and respected EBS specialists in the country, it was an obvious choice for the Eaton Group to collaborate with Airbrake Systems on the low voltage converter.
“We really know what works and what doesn’t with EBS for trailers, and we’ve certainly got a lot of connections in the road train space all over Australia, with direct links with the fleet,” Glenn says.
The client happily selected the harsh environments – tasking Eaton, Airbrake Systems and Air Brake Corporation, which provided the telematics and data on the trailer combinations with a 7,000-kilometre trial in Cloncurry, 120 kilometres east of Mt. Isa.
The real Queensland outback.
Eaton found the perfect vehicles for the trials– a multicombination road train set up, comprised of a Kenworth T909 with TRM connected with a 1x tri-axle A trailer and 3 x 6 axle dogs, all carrying a 120-tonne payload.
Cloncurry provided the terrain and temperature – a combination of sealed and dirt roads, coupled with scorching outback temperature.
The perfect mix to put the Eaton voltage converter through its paces.
Glenn Hambleton, Airbrake Systems’ General Manager, Sales and Operations, who was on hand for the trial, says the location was an “extreme condition test”.
“It had the combination temperature, the dust, all the conditions for a good test,” Glenn says.
“If you’re going to do that’s where you do it in those kinds of places – Mount Isa, Northern Territory, areas where there’s a lot of heavy dust, like desert sand, and corrugated roads.”
Air Brake’s telematics revealed in real time how the Eaton low voltage solution was working to keep power moving through the trailers, and the EBS, as opposed to a rival product used in the trials, enabling the Eaton team to find increased power performance.
The trials revealed that without the correct voltage, the overloaded converter would result in the TEBS, and its roll stability function, shutting off, or browning out.
With the converter needing up to 60 seconds to reset, a driver was therefore without the TEBS for that period.
Over 7,000 gruelling kilometres the Eaton unit did not turn off under a full braking load, while the TEBS unit switched off, resulting in 28 volts of power going to the back trailer and under a full braking load, with the Eaton converter registering a respectable plus-13 volts, while an alternative unit dropped to around eight volts, which can severely impair the trailer’s braking and stability.
The Eaton Converter had output voltage of 25.996Vdc, with a voltage drop range from 25.996 to 13.32 volts (12.676V variation under heavy braking).
The alternative converter, known as ‘brand X’, had output voltage of 25.435Vdc and experienced a voltage drop range from 25.435 to 8.489 volts (16.946-volt variation under heavy braking).
Senior Product Manager – Digital Solutions at Air Brake Corporation, Adam Woltanski, said the Eaton low voltage converter provided increased performance and safety in the trials when the TEBS was switching off.
“It (Eaton converter) behaved much better than the alternative during testing, with a much lower voltage drop,” Adam says.
“Our main aim through this is to keep the trailer safety systems powered on at all times. “With these longer combination vehicles, we need to make sure they’re always powered up to mitigate the risk of rollover.”
Nick Hope said the Eaton converter provided a key point of difference in the market.
“The Eaton one is different in its construction, where it goes through what they call ‘folding the power down’ to protect itself in the circuit, but without switching off. I think that’s the key advantage of our unit over the ones that are currently in the market,” Nick says.
Glenn Hambleton, whose company specialises in commercial vehicle brakes, supplying electronic brake systems to the trailer industry, and distributes Eaton voltage converters, knows all too well the importance of properly functioning TEBS.
“We started working with EBS trailer braking systems about 16 years ago, before they became mandated, and we did a lot of groundwork on trailers, specifically with the dangerous goods industry and fuel tankers,” Glenn explains.
Fitting up 55-metre road trains with TEBS, in locations such as the Northern Territory and North Queensland, Glenn and his team discovered that often trucks only had 12-volt power supply from the prime mover, resulting in the third trailer of a combination only receiving six or seven volts – not enough to engage the TEBS.
With the ADR mandating of EBS in trailers, Glenn saw a significant upgrade in the power supply from the prime movers.
B-doubles and transporters with two semi road train trailers and a dolly went from being towed by a 12-volt truck to trucks with 24-volt supply.
“Anything where the power is above 10, 12 or 13 volts, the EBS systems are going to stay alive,” Glenn says.
“Thirteen volts is a good range, because the EBS systems range from eight to 32 volts.”
Glenn says that anything above 18 volts – to 24 or 26 volts – is ideal for the TEBS to be ensure optimal operation.
The lack of power supply to the TEBS was a major issue for operators and service technicians.
“We see it all day, every day, every week, every month, every year, where field service guys are on the road putting out red lights on EBS trailers.
“A problem we see is generally water ingress, but the biggest issue is voltage drop on the brakes.
“That’s the first thing they (drivers) blame when something breaks, complaining about the braking, because once the EBS goes below eight volts they turn off. You’ve then lost all the electronic functions and the first thing it turns off is the stability control.”
The result is a non-ADR compliant very heavy, long trailer on the road that is extremely dangerous.
Glenn says the Cloncurry trial results were ideal for critical braking events, proving the Eaton converter’s reliability.
“It certainly has a high performance for durability the way that they’ve designed it. It seems to have a lot better cooling, thermal efficiency. It’s definitely more robust,” says Glenn.
He believes with the additional power from its 28-volt transformer, the Eaton converter is ideally suited to a range of longer truck-trailer combinations, such as a standard B doubles to a multiple road train combination, thus avoiding a drop of power to eight volts and ‘brown outs’.
Future goals
The trials have proved that the Eaton low voltage converter can effectively address issues of low power supply to the TEBS, with more trials to come.
“What is clear is that the Eaton solution will help. Other things will need to be done to keep testing it, but it has proven itself to be better than what’s currently on the market,” Adam Woltanski says.
“We can evolve it to become even better. As an industry, we come together and fix up all the bits and pieces to get to a stage where we have a system that we’re 100 per cent confident in.”
Nick Hope believes that continued collaboration in the testing process will be key to ensuring Eaton can offer the best solution to trailer power issues.
The Eaton team is now working with its engineering counterparts in Eaton’s US base on more trailer power solutions.
“We’re going to build something specific. It’s not something that America would typically see, so they’re leaning on us a lot,” says Nick.
“There’s a couple of ideas, and hopefully we’ll be able to push that out and get a think tank going. We’re very safety-focused in that regard.”
Couple with this is Eaton’s dedicated approach to sharing the converter technology with the trailer industry, particularly at trade events such as the Brisbane Truck Show.
After showcasing the 12-28 volt converter at that show, a number of major fleet operators around Australia have approached Eaton and Airbrake Systems to have fitted the converter as a standard feature, ensuring their vehicles were industry compliant.
“We were able to show off our low voltage solutions at the Brisbane Truck Show to find a challenge we could take on. Showcasing it to the fleet, trailers builders and truck builders ended up with great outcomes for us,” Nick says.
“That’s why the trial went up, and we had our client coming forward looking to try it on their units.”
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