RC Al wrote:Dave, if you were trying to work out the efficiency of the ssr, with the watts meter hooked up, would you be able to use either a voltage or amp meter accurately after the ssr to look for differences? Pretty pointless I realize, but I like numbers :smile:
Yes but you need a special volt meter to measure a chopped sine wave as well.
Even a true rms quality meter will sometimes not measure a voltage output from the phase controller, the same as trying to measure the output from a variable speed drive.
I use fluke 87 mk 5 meters at work.
The watt meter installed before the phase controller will give you a very accurate wattage being consumed but the voltage will not be correct.
The current will be constant throughout the circuit though.
Untill you drop below 50% output from the phase controller you are still feeding a full 240v but not a full sine wave so you get less power.