Which TVS diode for 230V AC mains?

[espresso]

Hello. I intend to get some TVS diodes for protecting electronic devices in my home. I don't know which one of the following two types would serve the purpose correctly. I need them for 230 V AC.

1.5KE300CA
Stand-off voltage: 256 V
Breakdown voltage: 285 - 315 V
Clamping voltage: 414 V

or

1.5KE350CA
Stand-off voltage: 299 V
Breakdown voltage: 332 - 368 V
Clamping voltage: 482 V

[hardwareguy]

Re: Which TVS diode for 230V AC mains?

The peak to peak voltage of 240V mains (it could easily go that high) is 339V and you don't want it clamping unnecessarily. Id use the higher voltage avalanche diode.

TVS diodes can't handle crap for current so I'd use them in the last stage of a device that has a spark gap as the first stage, MOVs as the 2nd stage and the diodes as the third stage.

Use a 800V or so breakdown spark gap, a 400-500V MOV and then the avalanche diode. Each stage should be separated by some impedance...a noise filter between each stage works great.

[espresso]

Re: Which TVS diode for 230V AC mains?

I already bought a few with 332 - 368 V breakdown voltage. I used it in conjunction with a varistor (250VAC, 1W).

[espresso]

Re: Which TVS diode for 230V AC mains?

And as for spark gap that you mention, I can obtain only one of the gas discharge tubes from this link
http://www.wuhuan.com.tw/zdr/zd3r.htm

I can get ZD3R 230 AW-D. Can it be used for this purpose?