sometimes curiosity is good

[laser3kw]

I am getting around to converting my Bridgeport to VFD for power. My mill is wired 230 3phase like other. It also has a 230 / 120 transformer hanging off the back to supply power to lights, coolant mister and DRO . I bought it off a shop rigged up like this, done nicely, not a hack job. I ran it like this for 15 years on 3 phase with no problems.
I hooked up the VFD to "test" and the mill ran just fine. Flicked on the DRO, it lite up then went out. I though I fried it. Hook the DRO to shop 120 and it worked just fine.I figured the transformer didn't like the VFD.
So today I figured I would rewire the mill for the VFD and controls. I figured I might as well dismount the 120 transformer as I know it doesn't work with the VFD. I open up the transformer panel and here is what I found:

I guess time hasn't treated it well.

 

[vekster]

Was it fused incorrectly? That is a bit of a mess.


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[laser3kw]

Was it fused incorrectly?

Well, yes and no.
there was a fused disconnect hung on the back of the machine. the 3 phase was ran into it. the "single phase" was tapped off the load side of the fuses and straight to the transformer. From the transformer to a quad box.
The fuses were sized for the motor and there was no fuses on the transformer side at all. The transformer was rated at 1000VA, about 8 amps at 120.But it was only running two 60 watt bulbs and a DRO (maybe an amp or two). That's maybe 3 or 4 amps.
The transformer wires in the picture have very brittle insulation. The other wiring all had pliable insulation.
Makes me wonder about consumer appliances that run 220 single phase and a neutral to provide a 120volt supply for on board electronics. In that circumstance the 220 volt would be protected by the breaker. I would hope they have a 120 volt fuse on board for safety.