The first one is already odd because it should be zero volts. I could imagine that this is just “phantom current” that’s somehow capacitively coupled and would break down with higher lead (low-Z measurement)?
But the 33.5V do not make sense. I am afraid connecting my valves now which are just rated for 24V. Am I making a mistake measuring?
Now, coincidentially, 33.4/sqrt(2)=23.6V . However, I am pretty sure my multi meter shows rms voltage and not peak voltage. For example, when measuring line, it shows 110V and the line voltage is definitely 110V rms and not 110V peak.
I don’t know where the 33VAC comes from, but if you measure the output from the power supply directly you will find it is 28-30VAC, despite being listed as 24VAC (at least that is what I saw when I measured it). I’d say it is likely normal.
Understand it’s an unregulated supply and voltage will drop (just a bit in my case) when valve turned on (NOT connected, that’s not enough!) but high voltage can already cause damage and no valve is turned on.
I have tested two power supplies from friends, one is around 27V, as expected and another one is 32V which I swapped with my friend. It’s still crazy out of spec, but at least a bit less.
