Skip to main content

Discovered an interesting problem with Gargraves (and maybe other types as well) uncouplers.

I had them wired as instructed, with the magnet lead "hot" and the circuit completed pressing the button on the "common" leg.

A caboose with the under-truck plate for activitating the coupler touched the magnet when activated and, making it's own "ground" welded itself to the magnet!!!

Reversed the wiring so the magnet lead is always "cold" until the button is pressed, sending current to it.

When the caboose armature touched the magnet this time, I released the button and the circuit was broken.

 

Wired all the rest that way and end of problem.

Original Post

Kerrigan;

Being an electronics Designer I must say I've seen this all too often. Many circuits are broken in whatever looks like a convenient spot. And they work, as long as there are no short circuits.

I too prefer breaking the Hot lead if I am doing the wiring, for the same reason.

There is one exception in my work designs, the Emergency stop circuit. That I wire with current always flowing, any open in the circuit and the relay drops to Normally Closed and puts the brakes on. This will immediately stop the system if a wire breaks or switch goes bad, so you are not running with an E-Stop that does not work.

Post
×
×
×
×
Link copied to your clipboard.
×
×