I own a Lancair 360 with the more recent electrohydraulic power packs.  I believe one of my landing gear relays have gone bad.  Does anyone know the source of this component?

Symptoms:  Pump does not come on and low pressure side is not pressurized.  Voltmeter measurements:  12V at low pressure switch, 12V at low pressure relay control post, 12 V at high current input to low pressure relay, 0 volts at high current output, Relay is hot.

The gear retract fine.

Try:

 

 

 

You may have wired the circuitry per Lancair's directions and that can lead to this problem

 

1. With the down circuit engaged (gear down sw), the gear motor breaker open and the hydro pressure low enough, the master switch was turned on for a long time.

 

2. The relay power fuse or breaker was not open.

 

3. Thus, the down relay was powered but there was no panel indication from the gear in transit light since it is powered from the motor power circuit.

 

4. Since it is an intermittant relay under power for a long time, it overheated and, after the power was removed, the melted coil insulation goo cooled and locked the plunger in the open position.

 

Consider this wiring:

 

1. the relay coil power circuit breaker or fuse should be connected after the motor breaker so that when the motor breaker is pulled all power to the entire electro-hydraulic system is removed.

 

2. the indicator light circuit should be isolated by diodes so that power is not backfed to the other relay.  If the diodes are small enough they should blow before the small indicator wire starts a fire should it become is shorted and is asked to carry the 50/60 amps of the motor circuit.  Otherwise, an inline fuse would help.

 

 

And Butt Connectors