These are S&C switches which were supplied with Driescher fuses which have been failing to interupt. They are DIN standard but I would retrofit if neccesary.
I tried Bussman, thank you, but their DIN are too low in current rating, and their E rated are too low in interupting.
Ideally I need 63A and 40kA interupting, and 250A 40kA, both at 34.5kV.
The only thing I've found are the G&W Power Assisted Fuses, but they are very expensive. I would require 4 sets to replace my 250A fuses.
Any other suggestions would be equally appreciated.