ECN Forum Forums Photo Discussion Forums Electrical Nostalgia Fuse blower plug?

Someone suggested this plug, with its loop of wire, was designed specifically to blow a fuse so you'd know which circuit the outlet was on. Does that sound right? Could it have served any other purpose?

Well, while it may not sound right, it sure sounds believable. There is never seems to be any shortage of Darwin Award contestants. I can't really think of any other use. Perhaps a warped idea of safety protection. Bolt the circuit you are working on, in case someone else energizes it?

Perhaps for a testing purpose? e.g. Identifying unconnected neutrals to pair off with corresponding lives when wiring a distribution board?

I am surprised the prongs on the plug are not more burned. I am thinking this is a joke. It certainly was not used much.

OTOH if it was a safety thing, sort of a fail safe LOTO, that might make sense. The guy replacing the fuse might be surprised tho.

This looks more like it may be used for a remote switch application: The other terminal on there probably goes out to the corresponding female pin on the other side. With this you'd take a switch of any properly rated type, some lamp cord, and make a tabletop lamp switch or similar.

Why someone did it this way, I will never know.

... when I first started, I did something like this. I was so paranoid of making a mistake that I had a multiple-stage test before working on anything. The final stage was to dead short it, first to verify the power was off and second to make sure it stayed that way.





I believe this is the correct answer.

The center screw might have been a ground (EGC) ?

Perhaps it is steup to 'ring out' non-energized circuits. ie: one prong shorted to ground??

Has anyone done a continuity check? What is the center screw attached to on the receptacle side? Looks like the 'hole' the wire is poked thru could have been a ground! Or am I dreaming ??

Thanks for your suggestions. The plug is on its way to the Digital Museum of Plugs and Sockets (so I can't perform any tests on it).

I have the New Zealand version of this plug in my toolbox.
We call it an interrupted phase tap-on plug.
The pin that plugs into the wall is connected via that wire to the other side (where you plug an appliance into).
This allows you to measure the current flow through the appliance.

I hope this makes sense.

Ah...you put an Amprobe on the wire!!!

Thanks Mike!

Now that makes sense...


Bill

Trumpy:

Matter of fact, Amprobe made (or still does) an adaptor to place 'in-line' with a load at a receptacle that the jaws fit into.

Unfortunatley, a lot of my test equip. was lost in the Superstorm Sandy floods.

yup. Like this or something else?

That's it Bill. Mine was black and an Amprobe accessory back then.

This one's been around a few decades...we have two of them at the shop.

Thank you for that; i still have the Amprobe, but none of the accessories.

I have a short heavy duty zip cord extension cord like you use for window shakers (14ga) and I separated one of the conductors for my probe.