On 7/13/2020 9:44 PM, Ralph Mowery wrote:
In article ,
says...

Dunno. Never saw the primary fuse open tho, maybe there isn't one. I
know there is a recloser on the primary somewhere that can open and
automatically reset but you usually only see that with a fault on the
primary, like a pole down.
I have seen plenty of transformers blow without taking out the
primary.
That is really not my area of expertise but next time I see my FPL guy
I will ask him.

If there is a fuse, it needs to be at the top where that disconnect
ring is.

http://gfretwell.com/electrical/transformer.jpg


This is similar to what runs down my alley and is common throughout the
city.

My secondary rack - "120/240" - has the neutral as the center wire.
Looks like your neutral is on top (where service drop support connects).

One phase of the 3-phase distribution runs down my alley and is 8kV
phase to neutral/earth (about 13.5kV phase-to-phase).

My secondary neutral is bonded to the transformer-can. The can is the
primary neutral. My primary neutral is the same as the secondary
neutral running in the secondary rack.

Any pole with a transformer (and some others) have the neutral connected
to an earthing electrode. Some are ground rods. I think some are disks
on the bottom of the pole. Neither is likely very effective, but there
are may of them in the system.

Most transformers here have a fuse, like in your picture. The
transformer I am on is connected directly to the primary and has an
internal overload. It is reset using a "hot stick" on a lever on the
side of the transformer.

The wire from the cutout drops to an insulator attached to the
transformer can. I presume this is a lightning arrester that directly
limits the voltage across the primary.

The wire from the cutout attaches to the primary feed with a clamp that
has a ring on the end of a screw, barely visible. A lineman can attach
a hot stick to the ring, unscrew the clamp, and safely disconnect the
cutout and transformer.


The disconnect can either be just a disconnect or it can contain a fuse
that when blown will let the disconnect fall down so it can be seen from
the ground. I thought I remember seeing one of those that had fallen
down when a fuse blew, but it had been around 15 years ago.

https://en.wikipedia.org/wiki/Fuse_cutout


I have seen some of them that were blown. When you know what it is it
is pretty obvious.