When a PT is rated at 100Ma @330-0-330 VDC and has 300-0-300 HT taps

[catnine]

 I would then imagine the 300-0-300 VDC HT is less windings and would relate to a less than 100mA rating, is that correct?

 

[tubeswell]

the 100mA rating also applies at the 300V taps

[kagliostro]

Voltage is related to the lenght of the winding (more lenght more voltage)

Current ability is related to the thickness of the wire used (more thick more current)

Kagliostro

[PRR]

> less than 100mA

More.

The primary is sized for 330V 100mA; it could stand 300V 110mA.

The 330V 100mA secondary is sized for the losses from 330V worth of winding. Same wire, only 300V in use, about 10% less loss and waste heat. However in 10% less space. But the adjacent space (the unused 30V) is cold.

300V 100mA is conservative and safe.

I'd call it 300V 105mA. But this is really over-thinking. You can always run 20% over rating, with more sag, more heat, less life; or vice-versa 20% under rating. And the difference is small. And you rarely know your current demand that exactly. So 5% one way or the other is "nothing".