please anyone can tell me what is this component?

 

please anyone can tell me what is this component?

That would be a metal oxide varistor. It's used to suppress voltage spikes.

eric

 

It will look like a large flat ceramic capacitor. Most of the time you will see them with heatshrink wrap around them. If they blow, sparks will fly (especially when you are running on 200 or 400+ volts - will blow a hole in the side of the MOV hence the heatshrink. A double layer might be good))
They do their job and protect the equipment.

 

thx all but Paragon i don't understand what do you mean exactly by "double layer"?

 

He means that they will put a piece of heatshrink tubing on, shrink it, and then put another piece of heatshrink tubing on over the first piece, and shrink that.

It keeps the pieces from flying around more effectively that way.

 

He means that they will put a piece of heatshrink tubing on, shrink it, and then put another piece of heatshrink tubing on over the first piece, and shrink that.

It keeps the pieces from flying around more effectively that way.

if you can get me a picture showing that heatshrink and how to add another one over it that will help me a lot

 

I don't happen to have a photo handy.

However, this Google search will return lots of images of MOVs:
http://images.google.com/images?hl=en&um=1&sa=1&q=Metal+Oxide+Varistor&aq=f&oq=&aqi=g1&start=0

This Google search will return lots of images of heatshrink tubing, and such tubing applied over various components:
http://images.google.com/images?hl=en&um=1&sa=1&q=+heatshrink&aq=f&oq=&aqi=g-sx2&start=0

 

Really depends on your voltage. When I was first introduced to an MOV, it was in a high power test lab equipment (we are talking 480V 3phase or whatever it was) and there was a surge over night. Machine wouldn't go on. Finally saw that the power boox illuminate inside when the power breaker was closed. There were the sparks. MOV was the size of a quarter with a hole straight through it. I think it had one thick layer of heatshrink on it which contained most of the sparks. The rest of the MOV was vaporized.

Anyhoo.. back to heatshrink. It is just the black tubing you slip over connection and heat with a lighter/match/whatever and it shrinks. usually can get 2:1 or 3:1 (shrinks to half or a third original size) Just get a diameter large enough to go over the MOV and have at it with the heat. Don't worry about double layering.