Thread
Confusion about replacement AC film caps
Hi again 
I have a mac plus that trips my house power soon after it's booted.
From another thread I found that the likely culprits are the two small capacitors mounted vertically close to the power switch.
I desoldered them last night and noticed that they are cracked.
The markings on them are 4700pF 250V Y class.
I'm in Australia and there is a local component shop called Jaycar that carry this sort of stuff but I can only find X2 class caps.
Like these : 250V AC Mains - Metallised Polypropylene Capacitors - X2 10nF
Their full range of these types of capacitors is here
There are others there with an N designation for which I have no idea what that means, e.g. 22N, 47N
I've read elsewhere that it's not good to replace Y class with X class and I don't want to blow anything up or start fires
Any advice would be greatly appreciated.
I have a mac plus that trips my house power soon after it's booted.
From another thread I found that the likely culprits are the two small capacitors mounted vertically close to the power switch.
I desoldered them last night and noticed that they are cracked.
The markings on them are 4700pF 250V Y class.
I'm in Australia and there is a local component shop called Jaycar that carry this sort of stuff but I can only find X2 class caps.
Like these : 250V AC Mains - Metallised Polypropylene Capacitors - X2 10nF
Their full range of these types of capacitors is here
There are others there with an N designation for which I have no idea what that means, e.g. 22N, 47N
I've read elsewhere that it's not good to replace Y class with X class and I don't want to blow anything up or start fires
Any advice would be greatly appreciated.
Type X is Across the line, meaning between Neutral and Hot.
Type Y can only be used across Neutral, or Hot to Ground.
You cannot interchange these.
You also cannot interchange Y1/Y2, and X1/X2 they are rated differently.
Type Y can only be used across Neutral, or Hot to Ground.
You cannot interchange these.
You also cannot interchange Y1/Y2, and X1/X2 they are rated differently.
Thanks Technight, So I assume I can't use the caps that I linked too.
The reason for my confusion is that in this other thread it was recommended to replace these caps with 10nF (0.01uF) Met Poly Class X2 X210N
Yea you cant replace Y rated caps with X, or X2.
You must use Y for Y, and X for X, Although I dont know if they make a universal or not.
Have a look here for further detailed information :http://www.justradios.com/safetytips.html
This site is based around tube stuff, but the concepts are still identical.
The purpose of these caps are to form a pi filter to prevent common mode noise from getting back into the line.
You must use Y for Y, and X for X, Although I dont know if they make a universal or not.
Have a look here for further detailed information :http://www.justradios.com/safetytips.html
This site is based around tube stuff, but the concepts are still identical.
The purpose of these caps are to form a pi filter to prevent common mode noise from getting back into the line.
I noticed that there is a larger filter cap. It looks ok but would it be worth also replacing this in an effort to solve my circuit breaking Mac plus issues?