Evaporative Air Con PCB

[Chrisk_81]

Hi Guys,

This is my first post, I was hoping someone might know the answer to following question.

What would be the purpose of a 222 ceramic capacitor parallel between line and earth on the supply side of a 240v to 24v AC transformer?

It was shorted on my dads evaporative air con PCB and took out the fuse. I've been unable to source a replacement as yet so I desoldered it, replaced the fuse and it is now running.

I would just like to know the function of this cap so I can decide if it's crucial to replace.

 

[KJ6EAD]

It's there to suppress the arc on the motor relay contacts. Without it the relay contacts will fail prematurely. The value seems low to me. Can you post a picture of the component?

 

[Chrisk_81]

It's there to suppress the arc on the motor relay contacts. Without it the relay contacts will fail prematurely. The value seems low to me. Can you post a picture of the component?

Aren't you referring to a suppression diode?

As stated and as can be seen in the pic, the cap is not connected to any relays.

 

[Arouse1973]

Probably for a bit of filtering / noise suppression. This should be a Y-Rated capacitor if the appliance has an earthed metal case. Ceramic types tend to go short circuit when they fail which is why the fuse popped. Take a close picture of the capacitor, we might be able to find one for you.
Adam

 

[Chrisk_81]

Thanks mate, I thought it might be to do with noise suppression. Do you think I could do without it?

I found them on eBay:
http://pages.ebay.com/link/?nav=item.view&alt=web&id=221644714696

 

[Arouse1973]

Thanks mate, I thought it might be to do with noise suppression. Do you think I could do without it?

I found them on eBay:
http://pages.ebay.com/link/?nav=item.view&alt=web&id=221644714696

Hi Chris
Yes they look fine. It is better to have the component in place than not at all.
Adam

 

[KJ6EAD]

Aren't you referring to a suppression diode?

As stated and as can be seen in the pic, the cap is not connected to any relays.

What, you expect me to read ALL of the words in your post!?

The capacitor is nearly invisible in your picture.