Pitot Heat Cycling

[rv7alamb@sasktel.n]

When I am flying with everything I normally have on in cruise on, with the exception of the pitot heat the system draws 17 Amps, steady. When I select the pitot heat on the system cycles constantly between 18 Amps and 26 Amps. Today, this was at 11,500 ft and minus 7C. It seems odd to see the Amps pulsing up and down? I am envisioning the pitot heat heating up and cooling off? Is this normal?
Regards
David Lamb

 

[dynonsupport]

The heated pitot does have the ability to throttle the heat based on the temperature of the probe, but it only pulls 0, 5ish, or 10ish amps, never 17. Are you using our amps shunt for measuring current?

 

[rv7alamb@sasktel.n]

Yes, I have an Amps Shunt to measure the current. The 17 Amps is my whole system on in steady state minus the pitot heat. When I select the pitot heat on it cycles 8 Amps from 18 to 26. For some reason it just doesn't look right?
David Lamb

 

[Jamie]

Hi David,

I would say that you may have the wires for the amps shunt not in the correct location. In the manual it has an A,B,C location. I would double check that first.

Mine, with engine off pulls 4 - 7amps, when engine is running the Alt is pushing +2amps back into the battery.