Is this an arc suppressor/snubber?

[Steve Blackdog]

Hi Folks

I have on a schematic in the power input/ standby circuit on the live leg

• a fuse
• a resistor 1M0 0.5W and a capacitor 0u1 250v in parallel bridging to the neutral leg
• followed by an NTC thermistor 5R 6A (on live leg) to the switch

I am struggling to find a standard cap that meets the .1uf 250v rating. Is the capacitor an arc suppressor? Can anyone point me to a .1uf 250v cap on the web?

I hope you can help.

Cheers

Steve

[Steve Blackdog]

Here's the extract from the schemo

[g1]

Line to neutral requires a class X rated cap. Search for 'class X cap .1uf 250V'
Here's an example: https://www.digikey.com/product-deta...802-ND/9370710

[Steve Blackdog]

I must have been searching with fat fingers as I have now found a .1uf 250v capacitor with no problem.

Still I am interested in the job that this capacitor is doing - presumably it is stopping the chance of a surge of power damaging the tubes?? Keen to know.

Cheers

Steve

[g1]

As far as I know it's for EMI suppression.

[Helmholtz]

No, it's not for arc suppression and not in the standby switch wiring. What's the problem?
Purpose is EMI suppression.
Does schematic give an explanation what the exclamation mark in the triangle means?
I suppose it's a 250VAC cap rated for X application, at least it should be.
Do not use a 250V DC cap here! Must be rated for 250VAC and should have an X approval. Only X approved caps can safely stand kV spikes on the mains.

Please post a picture that clearly shows the marking on the cap.

Edit: Missed the posts above.

[J M Fahey]

Agree.
The "!" symbol inside a triangle means "PAY ATTENTION!!! REPLACE ONLY WITH SAME RATING UNIT!"

And 250V there does not mean 250V DC by any means but "rated for up to 250V mains" with all the peaks it may carry.
Wouldn´t be suprised at cap being tested above 1kV DC

[Helmholtz]

X1: 4kV, X2: 2.5kV pulse ratring.

[J M Fahey]

^^^^^^ that.

[Steve Blackdog]

Ok that is really informative. Many thanks. I don’t have an original cap to show as I am building from the schematic - ground up.

I am proposing to use one of these:

https://uk.farnell.com/panasonic/ecq...-pp/dp/1198295