Lightning & Surge Protection - Page 1
Forum section: electronics / beginners

author: chrisstra84
author_rank: Contributor
timestamp: March 02, 2015, 06:33:37 pm
content: So, a little bit more protection for my scope, function generator and power supply. I have bought me a multiple socket with surge & lightning protection.Description form the manufacturer:-Total surge current: 30000A-Protects connected devices effectively against damage caused by overvoltages and avoids this high repair or replacement costs.-Safe function with integrated thermal monitoring with function indicator and outlet shut down.-Reliable and durable with high-performance components.OR?What do you think? Can it help me? Or are this all wrong promises? Do you have any experience with this kind of sockets?GreetingsChristian

author: electr_peter
author_rank: Unknown
timestamp: March 02, 2015, 06:57:36 pm
content: Surge current of 30.000A (or 3e1A or 30e0A) is easy, that is what they claim. 30000A surge current (3e4A or 30e3A) would require copper bus bars bigger than the thing.If you doubt the claims (and you should to some extent), rip it apart and see the quality for yourself. It may be good, it may be crap. See some videos from this guy:https://www.youtube.com/user/jjward/videosHe has done teardowns of both cheap crap and cheap good stuff. Price is not everything.Surge protectors can help to diminish voltage spikes, but your scope or fnc gen should already have them built-in. Additional protection is welcome, but it won't help if lighting strikes directly or very close to equipment.

author: cosmicray
author_rank: Frequent Contributor
timestamp: March 02, 2015, 07:52:15 pm
content: That 30000 amp surge rating sounds like the 12000 amp capacity of these jumper cables.https://www.eevblog.com/forum/chat/dangerous-car-battery-jumper-cables/msg607867/#msg607867

author: max666
author_rank: Frequent Contributor
timestamp: March 02, 2015, 09:03:49 pm
content: Quote from: electr_peter on March 02, 2015, 06:57:36 pmConfusion of European and English use of "." and "," here! They do claim 30.000 A = 30 000 A = 30e3 A, since it's a German product. (But you say you're from Lithuania, so I'm confused, because you should be using "," as decimal mark too)And 30 000 A surge capability doesn't mean 30 000 A continuously, which is why that value alone without the pulse duration is meaningless, but what does the consumer care "Oh look big number, let me count the zeros 1 2 3 4 wow, must be good then right?".I don't know myself, so I would be curious if there is a standard for surge current, surge duration, surge testing, ... there probably is, so I'm hoping some kind member will tell us more.

author: electr_peter
author_rank: Unknown
timestamp: March 02, 2015, 09:16:34 pm
content: Quote from: max666 on March 02, 2015, 09:03:49 pmPlease tell me for 1.000000000000 USD how "." in "30.000 A" is not considered a decimal mark? In Lithuania preferred usage for decimal is ",", but "." is also used. Not decimal separation (of 1e3 or 1e6) is usually skipped or used with a space " ", extra symbols just confuse everyone.QuoteMeaningless and confusing. Using similar logic I can claim that LM7812 is protected from 1MV and 1MA surges (for few fs at least...)EDIT:30A surge sounds like a motor starge surge current. With 230V RMS, 30A means up to 6.9kW - very serious power for a single phase.

author: VK5RC
author_rank: Unknown
timestamp: March 02, 2015, 09:21:37 pm
content: All my good gear uses power boards that link to one easily accessed power point, on leaving the shack, I pull the plug. My understanding is that the spike is very hard to stop. A close strike can induce bad levels of voltage, even on cables attached to the gear but nothing else.

author: Kjelt
author_rank: Super Contributor
timestamp: March 02, 2015, 09:40:12 pm
content: Brennenstuhl is cheap crap product. The switch fails ten out of hundred.Anyway what do younwant to protect? Direct lightning strike? Forget it, build anti lightning protection around the house to not get direct strike.Then what I do for my expensive hometheater equipment is shut it down with a big power relais (3kW type not those pussy pcb relais) when i do not use it and protect the front so before the relais with three MOVs and sparkgap. Still if direct strike I still be out of luck.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: March 02, 2015, 10:43:05 pm
content: Hopefully the power board has MOVs in it. But it doesn't actually say that so that is a problem.The standard test surges are IIRCClass I 10uS/350uS rise/fallClass II 8uS/20uS rise/fall.So yes the 30KA is a meaningless number without the rise and fall times.So I would avoid this product as it doesn't specify the capabilities correctly.30kA 8/20 is a small surge. But maybe ok for a power board as the board wont get the massive surge that comes at the switchboard.Quote from: Kjelt on March 02, 2015, 09:40:12 pmI have been told that Sparkgaps in parallel with MOVs is pretty pointless as they almost certainly wont activate simultaneously. Though MOVs work well in parallel if the same specs.The best protection you can have includes series protection. Basically a low pass filter designed for surges. With a bank of MOVs on the front and one on the back to stop ringing. The only downsides are expense and a small loss of energy in the filter.

author: max666
author_rank: Frequent Contributor
timestamp: March 02, 2015, 11:24:48 pm
content: Quote from: electr_peter on March 02, 2015, 09:16:34 pmDoesn't work that way, you probably meant to write 1.000.000.000.000 USD, because otherwise it pretty much can only be interpreted as 1 USDAnother reason why 30.000 A doesn't mean 30,000 A, is because if you would specify a value down to mA, you would claim to know that value down to mA exact. In this case I guess that would mean it can handle 30 000 mA, but not 30 001 mA (or at least around that ballpark). But I totally agree with you that extra symbols just confuse everyone, which is why I never would use anything other than a space for the thousands separator 1 000 000 000 000 USD, this way if there is a "." or a "," it can only mean a decimal mark.QuoteI totally agree, but yes you could. But for lightning and surge-protection, continuous current has no meaning, so you need a better way to characterise overload pulses.Also disconnecting your devices is fine and dandy, but what about equipment that has to run 24/7? You have no choice but to try and reasonably protect according to the likelihood of events and cost of expected damage.Thank you HackedFridgeMagnet for sharing. Specifying rise and fall time are even a little bit better than just duration.

author: electr_peter
author_rank: Unknown
timestamp: March 03, 2015, 12:29:49 am
content: Quote from: max666 on March 02, 2015, 11:24:48 pmIt means 1 USD. Additional "." for 1e3 and 1e6 just do not work (in Lithuanian language at least) and confuse everyone unless very clearly defined in a specific context. If you expect to use the same symbol with more than one interpretation and leave it to reader to interpret it correctly, you will get a mess. Anyway, enough of language nuances in this topic.

author: Kjelt
author_rank: Super Contributor
timestamp: March 03, 2015, 09:01:14 am
content: Quote from: HackedFridgeMagnet on March 02, 2015, 10:43:05 pmThey serve different purposes, the MOVs are typically tens of Volts above the normal mains and serve for small overvoltage protection.The sparkgaps activate at 4 to 6 kV's depending on the type and is a crowbar for extreme high voltages.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: March 03, 2015, 01:11:46 pm
content: Quote from: Kjelt on March 03, 2015, 09:01:14 amDifferent spark gaps and different MOVs will have different clamping voltages, though generally spark gaps will have a higher clamping voltage.But the problem is that the MOVs will die before the spark gaps do anything.For serious protection you need a Series Mode surge suppressor with Spark gaps on the front of a filter and a MOV on the back.

author: chrisstra84
author_rank: Contributor
timestamp: March 03, 2015, 05:21:45 pm
content: Hello together,At first, thank you all!I have sent an e-mail to Brennenstuhl to ask for detail information. I have asked them for rise and fall times, surge response time and MOVs (Metal Oxide Varistors). I will tell you, if they sent me an answer. I hope I get on.And I know there is not really a protection in case of a direct lightning strike. You can read this in the “Functions and direction for use”. The quality is not bad at all, I think. I would say the quality is between normal and good. I have no problems with the power switch until now. So I think it’s better than nothing. This device costs 27.99€, so I hope there is no mistake.Last but not least, I’ll hope never need this protection, but I have a better feeling with this.Christian

author: max666
author_rank: Frequent Contributor
timestamp: March 03, 2015, 06:17:42 pm
content: hehehe, take a look (sorry, only German, bottom line the "Brennenstuhl Secure-Tec Automatic" did not impress them at all):https://www.test.de/Steckdosenleisten-Viele-sind-nicht-sicher-4248836-4248841/I have an APC UPS and it says in the specs:Surge energy rating: 310 JoulesFiltering: Full time multi-pole noise filtering : 5% IEEE surge let-through : zero clamping response time : meets UL 1449

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 03, 2015, 10:24:35 pm
content: If they don't put a warranty on it, it's probably not any better than a common (fused but otherwise bare) power strip.Tim

author: chrisstra84
author_rank: Contributor
timestamp: March 05, 2015, 06:44:54 pm
content: Hello together,I have got an answer!They use test voltages with rise and fall times about 8/20µs. The typical surge response time is less 25 ns (<25ns). And yes, they use MOVs. There is a manufacture guarantee about 5 years and an insurance protection for damage to persons and property within their product liability amounting up to 5 million €.Christian