The pf effect must come from the control box, and makes sense.
IIRC the box uses triacs. These take a chunk of each power sine and
pass it on to the load. The chunk has to start after a zero crossing,
and continue all the way to the next crossing. If the power desired is
low; the delay is long, the current pulse (seen by the wall plug) is
short and the phase of the current must trail the phase of the voltage.
By some good fraction of 90 deg.
If the box contains a power oscillator (perhaps needed by the waveform
spec) to feed the triac, than this does not apply.
Ol' Bab
On 5/26/2013 1:46 PM, Claudio C Fiorini wrote:
SNIP...
The problem remains: how is it possible that a heating resistor may
produce such a massive phase shift with the result of a o.48 power
factor. Inside the reactor there is no place for any complex
electronic system of any kind, the hih temperature of 800+ degrees
Celsius would destroy condensers and any soldering.
