Dynon pitot heater feedbac

[thibault]

This question is for those of you that have the heated AOA pitot tube and have installed per page 15-7 of the manual.

Do you see the EMS widget cycle between ON and OFF during normal operation?  I swear that I used to see that, but now it always says ON unless I pull the C/B.  Then it says OFF like I would expect.

To verify that it really is cycling the heater, I put a jumper in the plus voltage wire and measured the current.  When the hangar is 80F and I turn on the master, the meter shows about 6.7 A for a few minutes, then drops to 66 mA.  Then it goes through repeated cycles of 6.7 A and 66 mA.

The probe gets hot enough that you can't hold it for long, but it sure does not feel like 80C.  Is this all normal?

 

[swatson999]

Are you saying your pitot heat is on whenever the "Master" is on?

 

[thibault]

Power to the heater controller (thus the pitot heating element) comes from a 15 A C/B, so yes. If the C/B is pushed in and the master is on, the heater controller turns on the heat whenever it wants to.

 

[davedubb]

Your status widget (indicator) should always show "on" when the pitot main switch has been turned on. Do you have the pitot control box hooked up to an auto reset breaker? If this breaker is auto resetting it may explain why your indicator is turning off and on. It may also indicate there is a fault in the system.

The low current draw may be because of a fault but may also just be because your battery is only at 12 volts and not closer to 14 as you would see if the engine was running.

 

[thibault]

There is no auto reset breaker, just the standard type of push on/ pull off.

I guess I was imagining that the widget cycled on/off.  Maybe what I really saw was the ammeter value cycling up/down when the heater cycled.  Can't see that in the hangar cause my ammeter is set up to show alternator output not system load.