OVPD-TM Over Voltage Protection Device with Test Mode


Planes these days have expensive electronics, from glass panels to lithium batteries, that need to be protected from an over voltage occurrence if your regulator fails. Your regulator controls the voltage output of your charging system, and if you have “unregulated” voltage event, your charging system can exceed the level of protection your electronics have and permanently damage them.

Some charging systems have over voltage protection as a standard feature, while others such as automotive engines do not.  This device works as a crowbar that will automatically and instantly shut your alternator off  once the voltage exceeds 16.1V so that high voltage levels do not reach your electronics and destroy them.  This can also easily be added to a charging system that does have over voltage protection so you have redundancy.  This is the safest and easiest way to protect you electronic investments in your plane.

This device is designed to “crowbar” the Circuit Breaker by applying a short circuit electronically and “pop” the current Alternator Field Circuit Breaker when voltage is over 16 Volts to protect all of your electronics in your vehicle.



The OVPD-TM is easy to install!

1- Determine a suitable mounting location near the Alternator Field circuit breaker (CB), and mount.  Often Velcro or a Nylon tie will suffice under your panel.

2- Connect the RED wire to the LOAD side of the circuit breaker. This is the side going to the alternator, not the bus. Use the included ring terminal.

3- Connect BLACK wire to a local ground. Aircraft ground or a ground block. Again, use the included ring terminal.

4- For the Test Mode Button (TMB) Model, use the included push-to-test switch to test the OVPD.

5- Push the Circuit Breaker back in to reset the device after the test.