Igniton xfmr

[ptonsparky]

Worked on boiler controls yesterday. Problem is no burner ignition. I needed a quick visual on when the pilot lit and how long it was on so I clamped my true RMS meter around the hi voltage secondary of the pilot ignition transfomrer. Figured I would be lucky to read anything but got 10-12 amps. Not shorted. Was this noise from the spark?

(Pilot lit each and every time and gas to main burner was off while we checked for voltage.)

 

[winnie]

Are you sure you got 10-12A, and not 10-12mA??

'Shorted' for an ignition transformer means something different than 'shorted' on a low voltage circuit. An ignition transformer has enough voltage to strike a visible arc between its terminals, so you can have a fault somewhere in the system which is 'open' to any meter that you might use, but where the arc strikes in an incorrect location, eg. inside the case. If you can _hear_ the arcing, and can't see it at the terminals, then you have a 'short'.

Okay, I admit it: my experience with ignition transformers is using them in 'Jacob's Ladders' (Climbing Arcs). You have to take care that the arc starts in the right place, and not somewhere in your electrode support structure.

-Jon

 

[ptonsparky]

My amp clamp won't do ma.