Can anybody identify what the device with the red plastic and "10 A"
(10 Amp) written on it is?  I believe it's a breaker or fuse panel of
some sort.  The red part pushes in (it's spring loaded), but does not
"catch" when pushed all the way in.

  http://www.megacz.com/tmp/breaker.jpeg

This is part of the electrical wiring controlling the motor for a
commercial roll-up door (motor mf'd by Baldor).

I'm interested in knowing if this is a fuse panel, and if so, where I
would get a replacement fuse.  If it's a breaker panel, I'd like to
know if the fact that the red part springs back out indicates that
it's broken.  And, if it's neither, well, just knowing that would be
great ;)

I?ll comment, because most researchers are bookish and wouldn?t know a
giggling pin from a foo foo valve :-)

It is a contactor -- at least that?s what they are called in the UK.
It is fact just a relay but in control gear applications they tend to
be called contactors, though sometimes ?control relay?.

On application of a small current to the energising coil, the red bar
pulls in with a satisfying ?clunk?. Thereby a small, light duty switch
can control a much higher current.

The function of the red bar (not always incorporated) is that one can
simulate the application of current to the energising coil with your
finger. While it is pressed, the heavy duty electrical contacts will
be mated and will supply power to the load.

They can go faulty though. Usually just the power contacts burning
out. The energising coil rarely fails. You can test it out by applying
power and either powering the energising coil or pushing on the bar.
If it doesn?t seem to function, replacements are readily available
(cheap) from electrical contractors or by mail from electronic
component suppliers. If you unwire it (taking note of the wiring of
course) you may find the manufacturers name and type for an exact
replacement, but they generally conform to industry standards.

Any help?

Best

guzzi, you rule!

your answer was both:
a) completely correct
b) enough to allow me to fix the larger problem I was trying to solve

Please post this as the answer so I can accept it.

Thanks again!!!!

Well done, Guz

And for his next trick ...

The Amazing Guzzi will now post his comment as an answer!

(This should be worth watching.)

Hahahahahaha Bryan....

Guzzi may surprise you yet...

Hey thanks megacz2. In truth though, you made the question very
straightforward so please award yourself the $10 plus a tip.

And the probo and steph double act -- I look forward to your national syndication.

Best

Guzzi, you're the best.  Thanks!!