I'm glad youtube recommended your channel. I get to learn something new each time I watch your videos. You are very well prepared and methodical in your explanations. Great Effort JW

I wish you’d been one of my teachers at school. Clear, engaging, and clearly invested in your subject. Superb.

Thanks John, this is a great video, really helpful to explain the use of and requirement for surge protection. Very few people really realise the true extent & cost of damage caused by over voltage issues, one reason for that is that the UK insurance industry is very tight lipped about these things. In Germany this is not the case the insurance industry makes information freely available and they suggest that from all claims of "electrical or electronic damage" over voltage / surge issues are responsible for 31% of the claims. That is a huge figure, for anyone reading this and thinking "he's an idiot, I've never seen anything like that level of damage" ....well how do you know? Over voltage damage is not always immediate and spectacular, there may not be a huge bang and plumes of black smoke. You can have several incidents over a few weeks and it would lead to wear and tear, then one day flick a switch on and the equipment doesn't work. Do you immediately think "oh that must be wear and tear fro over voltage events" of course you don't. You think "oh that's broken, more money to replace it /repair it". SPD's offer longer life spans for equipment, increased levels of availability, reduction in down time and less maintenance. They are like "electrical life assurance for equipment".

Another clear explanation showing what these things are, and why they now an important addition, thanks John

Thanks John, a very nice introduction to purpose and limitations of SPD's in general. Aside transients caused by atmospheric (lightning) you highlight the need for awareness of 'Surge Creating' equipment along with 'Surge Sensitive'.

After some time watching various sparky channels on KZfaq I will honestly say that your channel is most informative or/and pleasant to listen. Thank you. Negative comments I may write in private some time later on.

Hi John, . You explain things so interestingly and understandable for the non exspert, plus I love it when you go the hole way and let us see things burn out and set on fire.. Keep em coming John... Regards Antony Warrington Cheshire.

Loving the big Clive style bridge rectifier symbol :) great video as always

great stuff. transient change of pitch of the voice always cracks me up

Excellent video John as always very informative, fitted a couple of SPD’s on last few jobs now

Two years ago almost all the plugged in devices with circuit boards inside them all died in the same week, I always knew it was a surge but now I finally understand why. Thanks!

I knew a bloke called surge, he was French. I don’t believe protection was necessary as he was a great chap! Your videos are excellent, possibly the best on here. 🕺🏽🍻

Thanks John will share with family and friends!

I've known of two instances where lightning strikes have had a noticable effect. Back in the 90's I was watching the TV in a thunderstorm - suddenly all the lights "strobed" once and the tv went to standby. No damage, just had to turn the tv back on. The second, much more recent incident was during a particularly powerful thunderstorm - a friend of mine's Router and computer motherboard got fried (I diagnosed the computer and figured out it was just the motherboard that bought it). I think this is a good example of what John is talking about here.

Thank you for the lesson John

Most damage caused by surge I witnessed, was in the one of substations in a factory last summer. Surge (or few of them) busted the SPDs, but also busted electronics of a main circuit breaker and power analyzer. Later on, there was significant voltage drop that caused overcurrent, which resulted in melted 2500A busbars, because 2000A breaker didnt trip.

the best english electrician on youtube :D

Excellent videos thanks. I rewired a property following a direct lightning strike some years ago. It hit an extension part of the property and more or less demolished it. If there was anybody in at the time it could have been serious. 2.5 mm and 6mm cables had been vaporised in places. Seemed to use everything it could as a path to ground. Open reach or British telecom were there for a few days doing street works.

Excellent content and presentation , Sir !

Waiting patiently for part 2.

My kitchen had a mixture of fluorescent and incandescent lighting. I replaced the incandescent lamps with LED types and noticed that the LEDs were failing almost immediately. Finally it dawned on me that the failures were always coincident with switching the lights on or off. The only reason for this I could think of was that the chokes in the fluorescent fittings were causing a surge at switch on/off which was enough to damage the LEDs. I replaced all the fluorescent fittings with LED types and problem solved. Not particularly surprising I hear you say. However, two things are worthy of note. LEDs elsewhere in the house of exactly the same type/manufacturer were not being damaged although they were on the same lighting circuit. I can only assume that the extra wiring length to these other LEDs had sufficient capacitance to suppress the surges being generated by the fluorescent fittings. The other thing I was surprised by was that the LED manufacturers (a well known brand) had never heard of this kind of issue before and moreover did not seem to be very aware in general of how sensitive their products were to what I imagine are fairly minor surges in the great scheme of things (assuming my theory was correct!). Has anyone else encountered similar issues?

Whenever I need info on any electrical subject i check on KZfaq if John Ward has made an info video on it, you are the god on electrical knowledge 😉

Great 👍video with relentless explanations

You are the best JW

I live in a neighborhood with underground power, and also one that seems prone to lightning strikes. I've had a couple (that I know of) strike within a hundred yards of my house in the last few years and I've also lost two electronic devices due to them. I'm in the process of installing a whole house protection system, but I also wonder if adding additional grounding would help. The soil is heavily clay, so water doesn't go very deeply and the conductivity must be poor.. I'm wondering if I should add an additional grounding rod at the electrical service entrance and another to the outside air conditioning compressor at the far end of my house. In a nutshell, what I am asking is if improving the grounding will add additional surge protection, including that from induction motors starting up.

You're doing an excellent job, thank you :)

That was certainly good insomnia protection JW, just a quick correction, “high voltage transients” even those from direct strikes to overhead lines, don’t travel very far before they dissipate either by breaking down the air resistance and finding a path to earth, or the insulation between adjacent conductors and finding a path to neutral. HV injections (where a cross arm breaks, or a car hits a pole and one of the hv lines falls onto the LV network below it), on the other hand can really do some damage, because the voltage is low enough to travel down the network without flashing over, and it will continue to flow until the protective device upstream operates (current X duration = let through energy), and that little 20Ka MOV arrester you have there will either be a god send if it is properly installed, or, what the fire brigade will later identify as “the seat of the fire”.

Great videos John! Just had an interesting one, a mains sander plugged into and extension lead that also had two led work lights plugged into it , started and then stopped the sander after only a second, and then both led lights blew their internal drivers. Assume due to a switching surge from the sander ac motor?Would a type 1,2 or 3 surge protector saved them, considering they were all on the same extension lead?

Amazing explanation!!!

Most electronic devices have at least a token amount of surge suppression fitted. At the mains input you will often see a small (normally blue) disc called a metal oxide varistor connected across the supply input. These short out large spikes and have microsecond response times.

So does the protection inside multimeters and the derived cat ratings also have to do with these same surges?

Also the inductance of the transformer primary in anything with a linear PSU would stop any short duration pulse doing much of anything other than MAYBE breaking down the primary insulation (which would have resulted in a repairer just saying 'nah yer transformer's dud')

What about the meter? are they susceptable to transients. Also with the dire need for isolators on the supply, would it not be a neat solution to have the spds and isolator in the same box that could be fitted while the meter wasbeing changed?

One of my neighbors had a lightning strike come down his chimney (breaking some of the brickwork) and go straight into his television, which basically exploded. The surge protector strip that the TV was plugged into suffered no damage. One of those weird things lightning can do I guess.

very informative.. great content.. God bless you..

i think we could not use it as a replacement for the snubber circuit, could do you make videos on the snubber circuits?

Hi John. Can you give any further insight into why the regs says that if you have a 2nd sub board over 10mtrs away that you would need a 2nd SPD. If there is a type 2 at the origin (ie meter box) on a property with an underground supply and there is a mains board 15mtrs away would you need a 2nd SPD in the consumer unit as well? I assume that if the SPD has done its job at the origin there wouldn’t be any need for it at the consumer unit as well?

Indirect lightning is a real problem where i live out in the country - overhead lines for both electricity supply and telephone. First thing we do at the first sound of thunder in the distance is unplug the internet router and telephone from the incoming line, if we don't it often leads to a lengthy tech call to the BT fault center trying to explain to them that a lightning storm just blew up yet another one of their routers! Have lost several that way over the last 10 years i have lived here.

Does a lightening strike on a cable damage the insulation ? Does an underground cable need to be replaced if insulation damaged. Would that be a dangerous situation?

Geez.. this dude is the real sh*t....how did I not discover you before evades me. Such invaluable information broken down to dummy level. Pretty much you can be classed as the information digestive system for the average budding to even intermediate electrician. Break everything down to bite sized chunks. stuff u don't get in the classroom. Simply amazing. Pun intended:). Keep up the stellar job you are doing sir (as in teacher). A credit to the youtube community..

hi john , another great video. quick question. can you get surges in houses that are near the rail lines at all? .Also I noticed a shop near by me one time that was a barber shop underneath a railway bridge and every time the train would pass over their clippers would go completely ballistic and make terrible loud buzzing noises when using them. they would have to stop cutting hair with them until the train had passed. it sounds bizarre but that's what happened. Hope its not a stupid questions I have asked. many thanks.

Sir exelent explain thanq very much👌👏🙏

Great video JW, when can we expect part 2?

Brilliant. !!!

Thanks for the great video! There's only one thing I'm not sure I fully understood. Regarding the switching off the directly connected motor (without VFD), if it's done by 1p switching and you let the motor freewheel until it stops without applying any force to it, shouldn't the generator effect be avoided? I'm not disputing the transient switching effect here! Just the freewheeling generator effect

How does voltage go up if neutral disconnected ? Is this something we need to know.. Can u do a video on this.

which spd uc/mcov should we use in home appliances 275v or 385v spd for 220v home use?

Thanks for this post.please can you share to me cable and their suitable breakers.

Excellent thanks. Can you explain how to connect SPD to home electric circuit and how to select.

Do you have a video on whether it is safe to install a 110v lighting fixture into a UK ceiling fixture? Thank you.

Sorry if a silly question, but could you connect one of those to a tv aerial coaxial cable to protect against lightning strike?

Great explanation. I cannot understand why SPD's are being disregarded so much for domestic jobs even by the NICEIC, my local supplier says I'm the only contractor fitting them. Why are they so expensive I've just ordered some MOV's from a supplier at 10p each to experiment with. Looking forward to the next installment.

Hi John. Great video. Have you covered any videos on hot water cylinder heating elements and testing? Mainly mims cable or equivalent, I Would think NZ/UK cylinders are similar. Kind regards

Dear sir, installed two cameras with 12 v adaptor (SMPS) in two flats and electricity went off and on in the two flats at the same time(the same block) , and one device in one flat was malfunctioning , i mean how to check the voltage signal Quality is stable or not is it high than standard , what are the possibilities that could destroy the adaptor in one flat and the other not in the same building , also instead of opinion about the video could the signal that comes out of the APC Power bank could be deformed from scientific point of view

What annoys me about failures in boiler PCBs is that it's typically the failure of capacitors which can be identified and replaced for pennies.

Hi - can you please explain Lutron switches (dimmer switches) that control many zones (4-5). And also the wiring diagram of Lutron switches when arranged in two ways switches and an intermediate. I have not found it if you can can you please make a video or send me a website that can explain. Thanks

@John Ward Should plugs(connected to an appliance) spark when connected to an unswitched socket outlet?

How do I connect two pole surge protector to a distribution board

We normally use a double pole switch or isolator for Motor right?

Very informative thanks. I worked for 30 years maintaining and installing ,fire alarms , door entry devices, CCTV and public address including 100 volt line on large and small installations. We hardly ever had problems that you have referred to with equipment being destroyed. It was built to withstand such things and worked for years with out problem. So I would question why these things are being fitted, could it be another way of frightening the customer into thinking "that they have got to have these fitted"!!!! Or are these transients and surges a new thing I think not.

MOV will dissipate energy via heat, so no need for earthing? How does Earthing differs from MOV SPDs?

Does the surge arrestor get installed before the main breaker in the consumer unit or further" down stream". Some books I've read in South Africa says : install between the live and earth terminal. Haha its too vague... Need to visually see it?

Good Morning JW, Have you come across integrated Incoming isolator & Surge Protection devices such as Wylex’s REC2SPD? It is designed to be fitted on the tails between the meter and consumer unit, hence protected by the service fuse. Will be up to the energy providers I guess re. if they want to fit these instead of a basic REC2 isolator switch for existing installations (when a customer requests an isolator switch). Would help achieve the short cable lengths required more easily in some domestic installations. Would be interested in your thoughts. Thanks Adam

Good, useful intro 👍

Hi John, Ze, IR etc testing should be on the main switch or on SPD? THANKS

This is a bit off-topic, but I live in a fairly rural area in the US. Until a couple of decades ago, it was common for houses and barns around here to have lightning rods installed but I haven't seen one in years. Why did lightning rods go out-of-fashion? Are they not needed anymore?

Thanks GOD BLESS YOU

Hi John what is a different between T1 type SPD & T2 type SPD???... Many thanks. Keep well!..

Can any Line and Neutral connections be interchanged on a 4 pole SPD? Have to replace one which has N in left side but available one has N on left side. Would make wiring easier if I could use one L as Neutral connections and use the Neutral connections as L.

In Oz the high voltage is run above the 240 volt lines and if the pole goes over (car Acident) The two come in contact and there"s your surge.

Why is it that new build houses have fused spurs for kitchen appliances like fridge, washer and dishwasher instead of a unswitched single gang socket with isolator switch elsewhere? Something to do with regs?

Why A.C. 230 Peak voltage +325V does not affect SPD? It's because the peak time is very short? Thanks

my job is designing mains fuse boxes for local installers and i can testify that almost 80% of them have some kind of surge protection. also in my country i believe it is mandatory for government buildings to have a spd system. a single type 1 and many type 2's is the norm but if see a upward trend of type 1+2. also a new (ich) source of surges are PV transformers (solar panel) and car chargers. they store a huge amount of power and use computers and electronics to turn it on and of very fast. but if the software fails it can dump all of it by exedent. it wont hit the 5000V but anything up to a 1000V is to be expected. it will be way more local but they ar cropping up every ware. if seen a carpark that had 20 charging poles and one car owner used the wrong card to check out and it cause a emergency power down because of some software bug. in a instance almost all of the led street lights turned of and did not turn on again. it was a expensive bug that did not damage the charging infrastructure so it was only a problem in the real world.

John Static caravans are now being supplied with type 2 SPD's in the consumer unit. The SPD is fitted up stream of the 30mS RCD in the consumer unit, however, the spd is downstream of the 30mA RCD in the external supply pillar. What is the potential for nusiance tripping of a rcd caused by transient voltages being shunted by an RCD ?

With a telephone line, the Linebox where the line from outside is terminated, there is a component in the Linebox to limit surges.

That was good..now I know to go round and unplug everything of value or have sockets in the OFF position. ;)

Sir what is different between over under voltage control device and spd pls help

TVs made pre 1970 used Electronic switched mode power supplies, the number one cause of failure were clumsy customers watering their plants on top of the TV, number two was capacitors drying up as they used to get so hot or the CRT died after 7 or 8 years of use. Surges were not a problem then even though the electronic components were inferior to those available today. Any mains powered equipment that is supposedly CE marked should include its own surge protection device, the reality is the addition of this 15p component (MOV) is usually left out to save cost by unscrupulous manufacturers. I have seen MOVs fail spectacularly, I would not recommend using these in a plastic enclosure!

thanks where do i find part 2

Let's see you create a surge to test the S.P.

Please can you explain how 240v is obtained as the average of a sine wave alternating between +340v and -340v? Common sense would suggest the average voltage would be 0v…

Telephone lines are a special problem. One side of the telephone pair is connected to earth at the exchange (which side changes briefly prior to your phone ringing, to warn CLI there's a call coming). A lightning strike near you, or near the exchange can put a big transient between exchange earth and your mains earth. If you have an ADSL modem (aka ADSL router, aka hub), that transient is likely to kill it (the same applies to old dial-up modems). Yes, the modem's power supply will be isolated, but if the transient is large enough there will be some leakage current through the class Y noise-suppression capacitor (or even breakdown of transformer insulation or even tracking of damned big sparks across the PCB). A direct hit on the phone line or power line puts an even bigger transient on there. If you have a wired connection from the modem to your computer, that just gives a more direct path for the transient to take effect, and may result in death of your computer as well as the modem. Modems/ADSL modems are not designed to cope with large voltages between mains earth and phone earth. Depends on the technology inside, but 10V can be enough to fry a chip. Bottom line unplug the modem from the telephone line if there's a storm. Unplugging the modem from the mains instead isn't as good, since the mains plug is going to be touching or near objects at earth potential, and even insulators have enough capacitance for there to be leakage current to transients. Unplugging from both phone and mains is better, but if you're only going to unplug at one end then unplug from the phone line. I've had three modems killed by unanticipated nearby lightning strikes. Two times, the first I knew of the storm was with the nearby lightning strike that killed the modem. One time I was out of the house on a day when no thunder had been forecast but a storm brewed up anyway. One of the times I had a phone on top of my tower computer and there was a damned big spark from phone to computer case.

hello teacher I am an electrician in Thailand. I would like to ask the teacher how many technologies SPD has. What technology is there? thank you teacher If I use the wrong words, I apologize because I'm not good at English. I use a translator app, teacher.

Brilliant. Thank you.

@20:20 "Shart devices??"

Nice nice sir

So what you are saying older electronic stuff was made from better stuff and just better made. Computer PSUs always had a filter plug for the inlet there now only on Hi end stuff. Old tech took a beating and it was still ticking.

i have to three lightening strike jobs spreed over many years number 1 tv destroyed number 2 consumer unit blown from wall supply cable to house destroyed number 3 2weeks ago indirect strike lighting transformer and dimmer blown , so on number 3 an spd would i think have saved the day,all jobs in 0.5 ng flash density area page 102 18th edition. thanks for video john.

Why do sharpies on paper sound like nails on a chalkboard to me now?

In reality, I've yet to measure a UK voltage lower than 240v RMS. I'm always mildly surprised when engineers refer to our '230v' supply! Maybe it's regulated more tightly in Europe, but every meter I ever used gives something along the lines of 243v - 248v. This is in the South-East, but isn't voltage universal across the UK grid? Not sure.

Years ago my parents house was struck by lightning it went down the chimney and blew the aga right across the room and buried it in the wall opposite totally destroying the radio that sat on the sideboard along with the sideboard. I dont think a surge protector would have been any use at all in this case. And when my father got home he was berated by the neighbor who was very angry that our chimney pot was now lodged in his roof.

surge protection is important but a t consumer level this is not important as surge protectors can protect the devices, but do not protect the device from FM interference that occurs during the fault... In the Power System transients will always clear over the wavelength distance since the transients occurs form a Line-to-Line fault

surely now in the 21st century all these sensitive equip has it all built in to say the door entry or fire alarm without it would be a no brainer

Old saying among electrical engineers: Man makes surge/lighting protectors and God laughs.

1.21 JIGAWATTS!

So, modern devices don't have magnetic transformers, to save money, and they don't have surge protectors built in either, to save money. My television recently went bang, and the Freeview box won't work either. But they don't put anything worth watching on TV anyway, presumably to save money too.

Hi John, can you do a video on off grid installations, I'm off grid (£10k to connect) with 2Kw Solar , 15kwh 48v batteries, 3kva inverter and a 10kva generator. I've been on a sharp learning curve since getting quotes to get power connected, I was advised to not get a cheap AVC/AVR generator because of connection problems with Victron inverters, I now find that my capacitor controlled generator has a potential for power surges "apparently". The only issue we have found so far is the washing machine won't work ( power fault code displays) if you don't have 1kw or so load because the frequency goes up slightly, if I adjust the generator speed down the inverter/charger won't connect. Will surge protection shown in the video help with generators, another great topic is earthing. thanks for the videos.

About 10 years ago my home was affected during a thunder storm. The surge took out my TV, Alarm, Computer. Insurance Co. refused to pay out calling it an act of God. Next door neighbour also affected. I think SPD's are a good idea.

How much does it costs to get a smart meter peter mc donald

So the consumer has to buy the surge protectors and not the electricity supplier? If they put surge protectors on the cables then they would not reach the houses.