Snubber Cap

[David_NC]

I've used 1000V parts in this application for the last 40 years in production. Never had one fail.

Did safety caps exist 40 years ago? I wonder when they came into use. I haven't been into any of my late '70's to early '80's equipment enough to have noticed they type of cap they use.
Still, I don't think I'd use a standard cap that fails shorted to connect the AC line to chassis ground. We know caps fail, and having them fail putting line voltage on a chassis doesn't seem to be a good idea. If the cap is used across the switch, I don't think it failing shorted would be a huge issue, although it was in my situation. When the cap exploded, it shorted against the chassis. This put 120 volts through my DAC and PC's USB port, frying both. I wish I'd had a safety cap in its place; this one was 50 years old and hadn't been used in close to a decade until recently.

 

[gslikker]

Did safety caps exist 40 years ago? I wonder when they came into use. I haven't been into any of my late '70's to early '80's equipment enough to have noticed they type of cap they use.
Still, I don't think I'd use a standard cap that fails shorted to connect the AC line to chassis ground. We know caps fail, and having them fail putting line voltage on a chassis doesn't seem to be a good idea. If the cap is used across the switch, I don't think it failing shorted would be a huge issue, although it was in my situation. When the cap exploded, it shorted against the chassis. This put 120 volts through my DAC and PC's USB port, frying both. I wish I'd had a safety cap in its place; this one was 50 years old and hadn't been used in close to a decade until recently.

Yes, they did.
At least the green Rifa or alike caps (those sometimes getting cracks even when new) already existed and they at least had the German VDE logo. I do remember having tinkered some barn ventilator triac controller over 40 years ago, employing one.