Hello all.
I picked up a General Radio variac model W10MT3W.
It has the supplemental transformer 60-120V which I would like to take out of the circuit as I want a 0-150 range.
I opened it up and it looked really good inside the 10 and 3 amp fuses looked ok but the 10A cap felt a little funny when I opened it.
I plugged it in...
I read 50V when the variac was set to 0 and 80V when fully on.
I decided to check out the continuity of the windings and other stuff the main autotransformer checked fine. the supplemental showed no continuity.
I then checked the continuity at various places. at the output there is continuity between all three slots.... ground/neutral/hot...
I then checked continuity at the 4 terminal on off switch. there is continuity between all lugs when in the on position.
I took the switch out of circuit and it checks fine, when on only continuity between same sides but not across as it did when in circuit.
I then took a look at the 10A fuse that had felt funny and it was broken inside and no continuity between posts with a good fuse.
I changed the fuse holder with a known good one and reinstalled the switch. the thing shows the same behavior of continuity between
neutral and hot at the output and the switch.
I am not sure how to proceed from here. any help would be greatly appreciated.
I will try and post the pdf manual. a crappy wiring diagram I drew and some pics..
Thanks in advance.
Sorry if this is in the wrong forum topic. if so I will move it.
PDF manual -
http://www.w9slm.com/variac/manual.pdfCrappy wiring diagram-
Pics -