How does a half wave rectifier or phase control dimmer affect the triggering of a circuit breaker? For example, if a 20A resistive load was on a 15A breaker with a half wave rectifier. Now average RMS current is only 10A even though peak RMS is still 20A.
1 Answer
Now average RMS current is only 10A even though peak RMS is still 20A
No, it's 14.14 amps and quite close to the breaker's limit.
If the current taken is normally 20 amps RMS for a full AC scenario, you can project this to power by squaring. So 20 amps becomes 400 amps squared. It is the power that is halved by introducing a half wave rectifier so, 400 amps squared becomes 200 amps squared and, the effective RMS current is the square root of 200 i.e. 14.14 amps.
average RMS current
what does that even mean? \$\endgroup\$RMS(100%)/2
...though I see it now after playing around on Wolfram. Since I thought it was a simple relationship I was doing[RMS(1st half)+RMS(2nd half)]/2
which is were I got "average RMS current" from. \$\endgroup\$