What Is A Trailer Breakaway System?

If you’ve only ever towed small car trailers then you’ve probably never had to worry about having a trailer breakaway system. For Elecbrakes customers and anyone towing a trailer above 2000kg GTM, however, understanding your obligations in regards to a breakaway unit becomes an important consideration.

If you are towing a trailer or caravan with electric brakes that weighs more than 2,000kg, it’s a legal requirement to have a breakaway system (AKA an emergency brake system) fitted. The safety device mounts to the trailer and in the event of uncoupling during transit will activate the electric brakes and bring the trailer to a safe stop. To satisfy legal requirements, the device must be capable of keeping the brakes engaged for a minimum of 15 minutes.

How does a trailer breakaway system work?

There are three main components to a trailer breakaway system. These are: a battery, a switch and a cable connected to a pin. The battery and the switch are attached to the trailer and wired together. They are also wired to the electric brakes. The pin-end of the cable is inserted into the breakaway switch and the other end of the cable is attached to the tow vehicle. In the event of the trailer uncoupling the cable will pull out the pin. This would trigger the switch, which would use the attached breakaway battery power to activate the electric brakes on the trailer, bringing it to a stop.

An optional component is a breakaway battery monitor, to ensure that the breakaway battery has enough power to operate while towing. A breakaway battery monitor is mandatory for trailers registered in NSW.

Breakaway Battery

Most trailer breakaway systems are powered off a 12 volt battery. These are usually housed in a black plastic case. The battery will need to be charged fully before it’s first use and has an average life of two years. Keep in mind that after the pin is pulled from the breakaway switch, an activated system can drain the breakaway battery supply quickly. Some batteries can be recharged from the tow vehicle itself whereas others require an electric or solar charger.

Breakaway Switch

The breakaway switch is the brains of the operation. It’s the switch which determines when the breakaway system is activated. The switch is mounted to the trailer and wired to the 12 volt breakaway battery. In the event of unexpected trailer decoupling, a correctly installed switch will be activated when the pin is pulled out by the tow-vehicle. This activation will cause the trailer’s electric brakes to be engaged, bringing the trailer safely to a standstill.

Breakaway Cable and Pin

A breakaway cable is attached on one end to a pin which is inserted into the breakaway unit and secured at the other end to the tow vehicle. The cable is generally 44 to 48 inches long and should be attached so that it is shorter in length than the tow safety chains. This will ensure that the breakaway will be activated in the event of the trailer being disconnected from the tow bar but still connected to the chains. It’s important to attach the cable directly to a secure point on the tow vehicle and not on the tow bar. This is to ensure that the system would still work in the rare case of the tow bar itself becoming detached from the vehicle.

Breakaway Battery Monitor

A breakaway battery monitor is a device installed inside the cabin of the tow vehicle, near the driver, to provide a visual and sound warning if the breakaway battery charge falls below a specified level. In every state except for NSW, a breakaway battery monitor is optional. For those living in NSW or those who just want the extra protection and convenience of real time battery information, a monitor is a must. You can buy a breakaway battery monitor separately to fit most electric trailer brake breakaway systems.

Legal requirements: do I need a breakaway system for my trailer or caravan?

It’s important to know your legal responsibilities when it comes to towing your trailer or caravan safely and in accordance with the road rules. Regulations may differ slightly state to state but the standard national towing requirements are as follows:

• Up to 750kg GTM – No brakes required and no trailer breakaway system required.
• From 751kg to 2000kg – Braking is required on at least both wheels of one axle. These brakes can be either electric or provided by a mechanical override system. No breakaway unit is required.
• From 2001kg to 4500kg – electric braking is required on all wheels. A trailer breakaway system is required.

Special breakaway battery monitor requirements in NSW

If registered in NSW you must meet the extra requirement of being able to monitor your breakaway battery from the tow vehicle.

The VIB6 inspection bulletin from the NSW Roads and Maritime Services states the following:

1. It will be satisfactory if any trailer-mounted battery is constantly charged by the towing vehicle and a warning device is fitted to warn the driver (from the normal driving position) if the trailer battery charge falls to such a level as to render the trailer brakes incapable of meeting the requirements.
2. Trailers required to be fitted with caravan breakaway systems are not registerable if there is no means for maintaining the breakaway energy source in a fully energised condition (for example, if a charging and warning circuit is not fitted).
3. An acceptable warning circuit must incorporate either a visual or an audible warning device.

In addition to a trailer breakaway system, a crucial accessory for safe towing is a reliable electric brake controller. For the smoothest proportional brake response, get brake smart, get Elecbrakes.