Transformer question?

[WOPL Sniffer]

Damn, I have torn down dozens of 700B's and Series II's and never seen a straw in one... Lots of spiders but no straws.

 

[wattsabundant]

It is also important to put insulating washers on the through bolts to insulate them from the core or eddy currents and noise may result from these currents being developed in the bolts.

I was going to mention that, but thought I was getting long winded. I once worked on a 200A/125V battery charger where the nylon bushings got left out on the input transformer. The bolt through the core caused a shorted turn through the mounting brackets and completed the path through the cabinet. The core was way to hot to touch. The coil was ice cold. When I told the client to insulate the mounting feet from the cabinet I got some pretty weird looks. When it worked jaws hit the floor.

As for the Dixie straw insulator, it's made of the same craft paper as the outside wrapper on the core. It's quite common to use fiber washers underneath the head of mounting screws.

 

[grapplesaw]

Hi Don. We have been missing you

here are the straws in my dual 500