measuring rectified SCR clipped AC serial capacitor, true RMS ac+dc or?

[Redeeman]

Hello.

I am going to be measuring on a system where 230VAC is fed into an SCR, and then from there onto a bridge rectifier, where the load will be serially connected with an AC motor run capacitors for current limiting (around 140-150uf).

what i wish to measure is both the voltage and amperage draw, and i guess both before and after the scr+bridge rectifier.


i saw this: https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/

and ordered this, given its cheap price, as all I have now is pretty much one of those $5 cheap chinese meters (which back then cost $15 in my local store ).

would this ut210e be able to accurately measure the current draw both before the SCR and perhaps after the rectifier aswell?

and then for measuring voltage, since (i hope) i will be able to use the ut210e clamped on to measure current, i will need a meter to measure voltage. I was thinking of getting the brymen 257 as it seems to be a solid unit, and im done with unsafe cheap chunk(i assume the ut210e clamp one is safe on the count of clamping instead of probes) but then i noticed, only true RMS on the AC side. so would this give me issues here?

to be honest im not even fully certain how the waveforms are going to look with the capacitor in serial like that, and with the SCR clipping before the rectifier, but as i understand it, true RMS would be applicable to DC too, and in the case where for example three phases are rectified so theres always a DC offset and some AC ripple (or if it was a single phase with smoothening capacitor parallel connected?), right?

but in this case, theres only one phase being rectified in a bridge, so would this be "taken care of" with true rms AC mode? or does the serially connected capacitors do something to this?

Thank you all very much in advance

[tautech]

Welcome to the forum.

Tell us some more.
Is the SCR just used as a switch or for phase angle control?
You say the load is capacitively coupled through motor run caps, correct?
What is the load?

[Redeeman]

the SCR is used to clip the AC voltage to reduce it, it is one of those 230VAC in, 0-230VAC out type of things.

And im afraid i wrote wrong before, the motor run capacitors are to be placed on the AC side, so this would probably make sense to put before the SCR.

the load is resistive to my understanding, it is going to be an HHO cell, with a huge load of steel plates to conduct current through water.