If i use capacator of same rating but higher voltage what will be effect??

[moonnightingale]

What happen if I use .22uf 400v capacitor when the specified is .22uf 630v?

 

[uoficowboy]

What happen if I use .22uf 400v capacitor when the specified is .22uf 630v?

Your thread title does not seem to match your post.

If your capacitor is rated for too low of a voltage, you risk damaging it. Your effective capacitance will also be diminished, though that is mainly a problem with ceramics, I believe.

If your capacitor is rated for too high of a voltage, you're pretty much OK for almost all circumstances.

 

[Tahmid]

If the voltage to the capacitor is still safely below 400v, then there's no problem. Usually, you can allow for higher voltage capacitors as this does not usually cause any problems. If you use a capacitor with a lower voltage rating, it's only okay if the applied voltage is still a safe way below the rated voltage, otherwise the capacitor will likely blow up.

Only thing to keep in mind is, as the voltage rating of a capacitor increases, the ESR tends to increase, although this isn't a strict rule and is more importantly dependent on the capacitor.

Hope this helps.
Tahmid.

 

[poorchava]

It depends on type of capacitor. Generally it might work for short period of time, though the value is may be altered. In case of tantalum capacitors they probably will catch on fire or even explode.

 

[0by1]

That means you are forcing (applying higher voltage than its rating) a capacitor to store more charge than its capacity.
because Q = C x V -more the V, more the Q
which may damage the capacitor !!

 

[Sajjadkhan]

When you choose a capacitor for AC voltage, Always keep in mind the Peak value of it. In addition if you choose capacitors for snubbers like with Triac where you are likely to encounter transients then choose capacitor with value = AC peak + transient magnitude, else your snubber will not work.

Every device which is underrated for specific application or replacement is not good and it is obvious in above posts.