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EARTHBOUND RECREATIONAL VEHICLE TRAILER OWNER'S MANUAL
ELECTRIC BRAKES
A CONTROLLER installed in your tow vehicle will synchronize the trailer brakes with your car brakes. It
is designed to apply the trailer brakes whenever the tow vehicle brakes are applied.
NOTE:
Study all material provided with your particular brake control. If you don't understand the
information, have the installer explain the information to you or call the manufacturer of the controller.
In THE EVENT OF AN ACCIDENTAL SEPARATION of the tow car and trailer, the BREAKAWAY
SWITCH, if you have a properly installed battery on the trailer, will set and lock the trailer brakes for a sufficient
length of time to stop the trailer. The switch is
activated when the wire attached to it and to the car pulls out the small pin in the front of the unit. THIS
PIN SHOULD BE PULLED OUT, LUBRICATED WITH LIGHT HOUSEHOLD OIL AND REPLACED
EVERY 90 DAYS.
To prevent corrosion within the breakaway switch, pull the switch's pin straight forward and spray the
inside of the switch through the hole with an electric contact cleaner and reinsert the pin. A drop of light household oil
on the groove near the base of the pin will allow the pin to operate freely.
WHEN THE TRAILER IS CONNECTED TO THE TOW CAR, THE BREAKAWAY SWITCH LOOP SHOULD BE ATTACHED
TO THE PERMANENT FRAME OF YOUR HITCH.
When disconnecting trailer from tow vehicle remove wire loop from the frame. DO NOT REMOVE PIN FROM SWITCH
BECAUSE THIS WILL APPLY THE TRAILER BRAKES.
CAUTION
: Do not use breakaway switch for parking brake.
HOW ELECTRIC BRAKES WORK
The electric brakes on your trailer are similar to the drum brakes on your tow vehicle. The basic difference is that
your automotive brakes are actuated by hydraulic pressure while your electric trailer brakes are actuated by an
electromagnet.
With all of the brake components connected into the system, the brakes will operate as follows:
When electrical current is fed into the system by the controller, it flows through the electro-‐ magnets in the
brakes. The high capacity electromagnets are energized and are attracted to the rotating armature surface of the
drums, which moves the actuating levers in the direction that the drums are turning. The resulting force
causes the actuating cam block at the shoe end of the lever to push the primary shoe out against the inside
surface of the brake drum. The force generated by the primary shoe acting through the adjuster link then moves
the secondary shoe out into contact with the brake drum.
Increasing the current flow to the electromagnet causes the magnet to grip the armature surface of the brake drum
more firmly. This results in increasing the pressure against the shoes and brake drums until the desired stop is
accomplished.
HOW ELECTRIC BRAKES HELP
Electrically actuated brakes have several advantageous features over other brake actuation systems.
1. They can be electrically adjusted to provide the correct braking capability for varying road and load
conditions.
2. They can be modulated to provide more or less braking force, thus easing the brake load on the towing
vehicle.
3. They have relatively no lag time from the moment the tow vehicle s brakes are actuated until the trailer
brakes are actuated.
4. They provide a separate braking system to that of the tow vehicle, which can be of benefit in the event of
tow vehicle brake failure.
