PS Audio (Paul McGowan) you tube “Phase Linear Gear”
- Thread starter InPhase
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This is actually a very useful thread (and still on topic).
It is important to point out capacitor AC ratings, and never to use a DC only rated capacitor on an AC circuit as Don pointed out.
Capacitors for use in filtering AC are of two different types regardless of uF value.
Type X is a capacitor rating for "across the line" or AC Hot (black) to Neutral (white). This cap should fail open but if it shorts it will open a circuit breaker or blow a fuse. Type X shows up as X1 which is tested to 4,000 Volts, and X2 which is tested to 2,500 Volts.
Type Y is a capacitor rating for "line to ground" or AC Hot to Ground and AC Neutral to Ground. This cap should also fail open but if it shorts and the chassis is not grounded, the case will become "hot". Type Y shows up as Y1 tested to 8,000 Volts, and Y2 tested to 5,000 Volts.
Many AC caps are dual rated such as Mouser P/N 72-VY2103M63Y5US63V0, which is a X1 and Y2 rated capacitor (X1 to 440VAC, Y2 to 300VAC).
It is important to point out capacitor AC ratings, and never to use a DC only rated capacitor on an AC circuit as Don pointed out.
Capacitors for use in filtering AC are of two different types regardless of uF value.
Type X is a capacitor rating for "across the line" or AC Hot (black) to Neutral (white). This cap should fail open but if it shorts it will open a circuit breaker or blow a fuse. Type X shows up as X1 which is tested to 4,000 Volts, and X2 which is tested to 2,500 Volts.
Type Y is a capacitor rating for "line to ground" or AC Hot to Ground and AC Neutral to Ground. This cap should also fail open but if it shorts and the chassis is not grounded, the case will become "hot". Type Y shows up as Y1 tested to 8,000 Volts, and Y2 tested to 5,000 Volts.
Many AC caps are dual rated such as Mouser P/N 72-VY2103M63Y5US63V0, which is a X1 and Y2 rated capacitor (X1 to 440VAC, Y2 to 300VAC).
Indeed the cap mentioned above is rated for 220 VAC, although it is peak voltage, not RMS. Of interest is the DVDT spec, but the spec is not defined.
The ceramic disc I mentioned earlier was just one of many that came up in a search at Mouser. I can recall one ceramic disc failure which was used across a power switch on a preamp. I think it had a broken lead. I've seen, I would guess 2 dozen 1000VDC film caps that have ruptured. They typically lasted 5 years or more before failing and did not have an AC rating. These were used "across the line" on a 208 volt, 3 phase source. Finding a suitable cap rated for that application did not reveal a lot of options.
Summary: The film caps may very well be suitable. It may take 5-10 years before we would know for sure. If they do fail, the expected failure mode would be a short circuit and result in a blown line fuse.
Edit: This was posted befored I saw Marks' response above which makes this post somewhat redundant.
The ceramic disc I mentioned earlier was just one of many that came up in a search at Mouser. I can recall one ceramic disc failure which was used across a power switch on a preamp. I think it had a broken lead. I've seen, I would guess 2 dozen 1000VDC film caps that have ruptured. They typically lasted 5 years or more before failing and did not have an AC rating. These were used "across the line" on a 208 volt, 3 phase source. Finding a suitable cap rated for that application did not reveal a lot of options.
Summary: The film caps may very well be suitable. It may take 5-10 years before we would know for sure. If they do fail, the expected failure mode would be a short circuit and result in a blown line fuse.
Edit: This was posted befored I saw Marks' response above which makes this post somewhat redundant.
Don, between the two of us we have both seen our share of blown caps. I appreciate your insights. BTW, I just ordered 100 of that ceramic cap you called out. I did the research and found that the cap you mentioned has straight leads (my cap had kinked leads), and your cap is 2mm smaller.
Your cap has a temperature rating of 5VS, mine was 5US. I could not find that spec, but the two ratings are in the same class, so they are similar.
Thanks for your input.
Your cap has a temperature rating of 5VS, mine was 5US. I could not find that spec, but the two ratings are in the same class, so they are similar.
Thanks for your input.
