I have a 120/240vac. 32A Autotransformer.
I have attached a current clamp once switched on it is drawing 10a with no draw from the 120vac. the input rush current is also at 29A.
The transformer is attracting Bees it is humming so loudly.
Have I got a bad unit or is this to be expected?
The input seems very wrong. Are you measuring across both neg and line? Unless you have a very fancy clamp meter, you can only measure across a single leg of the AC, either L or N, not both.
So I am using a clamp across 1 leg to get the reading. I also attached a scope to record the inrush current. It would be nice to find out if this is what is expected of the unit - the 110vac legs are constant voltage so the unit is working. just the no load on output and still drawing 10a 'Just' to run!
That is not normal. The no load current should be very low. I don’t know what that number is but it certainly not 10 amps. The inrush figure is hard to comment on because a high inrush would be normal but only for a very short period of time. That means 29 Amps for 2 milliseconds may be ok but 29 Amps for a second is definitely not ok.
Was this issue ever resolved? I am getting the same thing with a new Multiplus Inverter/Charger. Under NO load, it initially consumes 2.2 amps (30 watts). After a couple of minutes, the unit begins buzzing and the current gradually ramps up to 9 amps.
