On 4/10/2011 11:29 PM, Phil Allison wrote:
"Jeff Thies"
Phil Allison wrote:
"Jeff Thies"
Phil Allison wrote:

I suggest you provide the next replacement for that vulnerable tranny
with
some "protection" - firstly an in-line fuse of say 1/4 amp AND a
capacitor wired across the primary of say 1uF rated for continuous
use
across the AC supply.

If there is an overload on the tranny, the fuse will blow.

The 1uF capacitor should suppress spike voltages enough to save the
tranny from harm.

1 uF sounds a little high.


** No it ain't.

I thought you had simply misspoke and that this was an honest error.

The reactance of a 1uF cap at 60Hz is: 2652 ohms (1/(2*pi*F*C)
Online calculator:
http://www.kusashi.com/reactance-c.p...&stage=results

V^2/R = W

Assuming primary, as why would you put it on the secondary:

120^2 / 2652 = 5.43 W

Does that not seem wrong to you?

** Completely.

Such a cap dissipates no energy at all.

What planet do you come from ??

What a jerk you are. You do realize that is 45mA running through that.


** What sort of know nothing JERK thinks that capacitors dissipate energy
??

It doesn't have to dissipate energy to explode. That is a lot of joules.

Then proceeds to calculate the reactive impedance and treat it the same as
resistance ??

Big bad.

So I left out the PF, so what?

Zero out of ten.

My first encounter with you, but no doubt others have had the same
reaction. Telling an inexperienced OP to put in a 1mF cap without any
specifics, and that for the dubious goal of "suppressing" the back EMF
of a motor running off the line has a disconnect from reality.
Transformers are generally much hardier devices than the solid state
components they feed.

Say what you want. You've already made your mark and I really don't
care what you add. I've taken away what I need to know about yourself,
and the OP is off somewhere else.

Happy now?

Jeff


.... Phil