Hi,

I'm new to jet modelling and have nearly completed the setup of my new Rookie with a JetCat P120. I would like to know why jet modellers fit additional emergency shutoff features when the JetCat ECU has an auxillary channel just for this, plus failsafe???
I would appreciate your feedback.
cheers,

Andy

I've subsequently found out that an additional emergency cutoff is mandatory in Australia so my post is a moot point....i'm still for simplicity though.

The independent shut off is for when the speed controller shorts out and runs full voltage on the fuel pump.

A relay controlling the ECU power supply would be just as effective as a servo-operated valve. It may be more reliable since servos are much more complicated than relays. Make it so the relay has to be on to energise the ECU.

Phil,

thanks for your feedback. i'm going to install a microswitch actuated by a small servo that will interupt the power supply to the fuel solenoid. this will be my emergency shutoff, so the ecu (if it chucks a wobbly) will still have power. i suppose i could have this switch on the ecu power supply but i'll try the solenoid way first. not sure what the ecu will do in this case, whether it will automatically go into its cool down procedure?

I'd make sure the pump lost power too. The solenoid could stick or get some dirt in it. That's why I suggested removing all power to the ECU. I would put the switch in the pump power leads if you want to keep the ECU on.

I will leave the Jetcat guys to comment on what would happen if you interrupt the solenoid or pump power and leave the ECU running.