What is a Surge Protection Device (SPD)? and How Do They Work?
2024 ж. 14 Мам.
48 235 Рет қаралды
Surge protection devices or SPDs are an essential component to protect modern electrical installations.
This video is part of a circuit protection series in association with Schneider Electric. Register for the FREE training module as part of your ongoing CPD
hub.efixx.co.uk/SE-cprotection
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00:00 Schneider Electric circuit protection series
00:20 Surge Protection Devices - SPDs
01:10 What are electrical surges?
01:40 What causes an electrical surge?
02:46 How can we protect against electrical surges?
03:30 Wiring regulations and surge protection
05:10 Should you fit an SPD?
05:25 SPD end of life
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This video is part of a circuit protection series in association with Schneider Electric. Register for the FREE training module as part of your ongoing CPD hub.efixx.co.uk/SE-cprotection
Back when I worked at a PC service shop, the most common lightning surges I've encountered came down phone lines, usually damaging the phone, Sky box (back when they required a phone line), Internet router and any Ethernet device plugged into the router. In the dial-up modem days it was also common to see badly charred modems, although surprisingly the PCs were usually fine after fitting a new modem or network card. We had a power surge about 20 years ago in the middle of the night where I'm glad we had surge protected power strips. We noticed the RCD was tripped in the morning and wouldn't reset until we unplugged the chest freezer, which died with a ground fault. The microwave oven display and a mobile phone plugged in were also dead. Our TVs, PC, printer, etc were all plugged in surge protected power strips and all fine, even though the "Protected" LED on one of the TV's power strip went out.
Great to hear your experiences, thanks very much.
Brilliant, thanks for sharing this, I am about to get one fitted into my home supply as well as an AFDD (I saw your video on that too). Love his channel 🙂
Definitely a good idea. A lightning strike found it's way into my house once. Two TV's, a laptop and three landline phones died as a result. I ran an electronics repair company for a long time and whenever there was a lightning storm I would end up working evenings and weekends to keep up with the workload. Quite lucrative actually.
Thanks for your input
I've been fitting SPDs as standard when it was first mentioned in the 18th edition regs. No point giving the customer thr choice. They'll thank you when it does its job.
Once had a Herbert turret lathe that used reverse current to brake the chuck. Beiing an old machine, it had a cotrol box the size of a small car. The breakers were lage copper contacts which needed cleaning regularly. One day, one of the contacts did not close properly and it blew the main fuses on the board, blew the telephone repeater bell off the wall and destroyed a joint in the main cable outside in the road.
Which one is the one who disconected when fault occurs ? I have one in my country but it takes 0,5 seg which is pretty slow considering that a spike could be faster than 0,5 seg
Brilliant contents as all ways Joe… that picture looked liked beanfield Avenue 😂
Ha! Excellent spot Matt, it's also Corby power station. 👍
Does lightening rod can prevent the appliances damaging from lightening without surge device?
Brilliant video Joe, I'm going to send this to my customers when I need to explain about SPD's Keep up the great work
I used this device, it is way expensive but it can save you devices
what happens if i connect the SPD to the neutral instead of ground? since i don't have ground wire
You would think they would have to make an annoying bleep when they are non functioning. Probably would have been better to make it a requirement for new installations or board changes. Can they be retro fitted outside the board in their own enclosure ?
If you have an SPD do you still need surge protected power strips?
I know that road in Corby with the Pylons blasting through the housing estate...
Is the wear of the spd related to how many surges it has protected against?
Not just quantitative considerations.
I think giving the installation owner the choice is a happy intermediate option until amendment 3 makes it mandatory.
Very possibly.
Very good and informative as usual but at some point the DNO will have to take responsibility for this
They do have surge protection for their own kit, but their responsibility pretty much ends after the origin.
@@efixx This really needs to change as the DNO's are providing a service to a Service Level Agreement with the end user customer but you eFixx guys already know all this and are trying to move things forward!
if i had the money to build my own house (i hope my numbers come up soon), i'd make sure that all 3 types of surge protectors (and other protective devices like RCDs and AFDDs) are installed, even if they're not required by regulations.
if we all have spds in our consumer units would this make things like surge protected extension leads extinct and do these products actually protect equipment e.g. masterplug surge protectors do these actaully work and save equipment?
It's better to have multiple levels of surge protections so even if you have SPDs, using surge protected leads is a good idea too.
@@1idd0kun i always use surge protected extension leads round my tv and computer setups despite having an spd i just wonder from taking apart surge protected extension leads especially the cheap baq special PMS branded ones will they actually protect against surge as affectively as an spd reason i say this is some of the components look puny and insignificant
@@kierantvyoutube3591 A surge protector works by diverting the voltage spike away from the circuit or device that's been protected. The SPD is the first line of defense, so to speak. It will divert part of the spike to earth. But it's not perfect. Depending of how big the spike is, the SPD won't get rid of it completely. Whatever is left of the spike will be handled by the surge protected extension leads.
Can't put it better than the responses to this. 👍
In the industry, we commonly use a 20 or 30A breaker to safeguard the SPD (Surge Protective Device). If a lightning strike causes a surge of high current through the breaker and the SPD, the question arises: will these breakers trip, and if so, will their activation impact the performance of the SPD?
No. SPDs should be placed upstream and parallel to RCDs.
@arias4663 Have you heard of T2 SPD requiring an OverCurrent protection by means of an MCB fitted In-line with the SPD? (Yes, the SPD are wired Parallel/before the RCDs in Split-Load arrangement)
I usually just install it.
Does this cover an EMP?
@@luckyjoestar7938 The connected cables act as antennas that couple surges into the target device, and EMP testing I've seen shows that disconnected devices are less susceptible. Likewise, much of the damage done by an EMP is due to triggering conditions that allow energy already present in the device to cause damage (such as in CMOS integrated circuits where the EMP can turn on both the pull up and pull down transistors to a given node at the same time). When something is off, the only energy that can do damage is that in the EMP.
Seems like a cop out to me with regard to fitting SPD's in domestic installations ( in the latest BS7671) How the heck you can ask a domestic user to agree /disagree on this ?? Most domestic users would not have a clue. When I used the formula in the "old" BS7671:2018 - which actually wasn't that difficult to do -in many cases it showed that SPD''s weren't required -but -I was advised by my assessor "to fit them anyway" with regard to the clauses mentioning danger to life and property etc . Seems to me that this was all rather "vague" / few bothered with using the formula - and hence it was removed. Anyway - passing on to SPD protection itself -there is a requirement to keep the earth lead from the SPD below 0.5 M in length, - and that begs the question - exactly WHERE does the surge energy go when the SPD operates ? It would seem to me that there is a means for this energy to be also "dumped" to ground via the main CPC system ( back to suppliers earth in the case of a "TN" system ) - and so - the question of length of earth cable comes into question with regard to its DC resistance AND Inductive reactance - since: The transients will be of short duration and thus will contain high frequency components where inductive reactance "Xl" could be significant (XL = 2 * pi * Frequency in hz * inductance in henries) So the inductive reactance could be significant - and keeping leads short minimises XL ( and of course DC resistance) or - put another way: Keep the "impedance" of the system low - where impedance = the vector sum of R + Xl or, for the electrical engineers : R + jXl Those of us that are also Radio Frequency Engineers will know this perfectly well with regard to earthing radio communication systems - it is just that if you only ever consider 50Hz - the effect of inductive reactance is negligible in most cases - but here we are - all of a sudden as "sparkies - having to consider the effects of transients lasting milli seconds or even microseconds !! As the song goes: "It's a whole new world" !! It seems to me that this whole issue of "SPD" is not well presented in BS7671 - and indeed not well understood either by many - and so - the default position is "just fit it anyway" -- it becomes just a "box ticking" exercise ....... so ...... if that expensive smart TV fries .... you can say hand on heart : " it wasn't my fault gov! "
The requirement is not below 0.5m that is a recommendation, less than 0.5m if possible and never more than 1.0m. Length of cable is critical to maintain the voltage protection (Up) of the device. for every 1m (or part thereof) over this length you can add up to 1000V to you protection level turning an SPD with a Up of 1.5kV into a 2.5kV device and so on. BS 7671 really wants to see the 2.5kV Up as the maximum hence it recommends 1.0m (most SPD's are able to achieve the 1.5kV or slightly less). Inductance does play a very large part in SPD engineering and theory. As shown by Joe at the start of the video transients are not 50Hz , the are very high frequency and can equally effect your data and IT cables as well as your LV. BS7671 also says in regulation 444 that installing coordinated surge protection to all cables is a good way of mitigating and managing the effects of electromagnetic interference.
3:55 Indirect lightning 'strokes' ..? 🤔
Yeah, that is the correct term. 👍
@@efixx Interesting, I never knew that, Wiki thinks differently though en.wikipedia.org/wiki/Lightning_strike I think I would as well, if I got hit by lightning, assuming I lived to tell the tale 🌩😵💫
Do you need to mention that the SPDs need protection by a suitable MCB?
Interestingly, the SPDs that have been retrofitted to what was a split load Hager board does not use MCB on the SPD. It’s connected directly to the output of the 100A isolator using dedicated bus bars. However, my second Fusebox board does use an MCB for the SPD.
It's all down to the manufacturer as to whether you need an MCB. 👍
@@efixx I'll take your word for it Joe. I'm just a BG fitting amateur!
surely the future owners of the property matter !?
Yup. 🤔
👍👍👍
Don't most people these days use multi-way adapters with in-built SPDs anyway? Obviously if getting my consumer unit changed or getting rewired I'd want an SPD in it, but mine had a CU change shortly before I moved in.
Good surge protection has three layers. Course (type 1, or old type B), intermediate (type 2, or old type C) and fine (type 3 or old type D). There are also combinations available that contain several types in one SPD. Type 1 limits the voltage to 1300 to 6000V. It is designed for currents between 50 and 100 kA. Usually it should be installed before the meter. Type 2 ist usually installed within sub-consumer units. It reduces the remaining surge further. The maximum surge they can handle is usually 1500V, that's the reason there are several steps. They can handle a voltage of 337V for 5 seconds before they blow. Type 3: Protects socket outlets and connectors. It reduces the remaining surge to a level appliances should be able to handle. They build up on each other. If you lack one of these steps, the whole system can become useless. There are also SPDs that contain combinations. Mostly type 1 and 2, sometimes also type 3. There are also small SPDs that are fitted into connection terminals of socket outlets. Surge protection must be as close as possible to the appliances that require protection. The thing is, if there are more than 10m cable in between the SPD and the appliance, you should at least install another SPD (of the proper type) into the system. That is also the reason for the existence of these multi-way adapters. So thinking that the SPD in the CU is sufficient, no it's not. And these small surge protectors in the adapter are also not sufficient when used alone.
@@Marcel_Germann Well yes, that would be ideal, but I am not paying out for it to be put in if the CU is otherwise fine. I'm sticking with the "connection terminals" kind (which includes the multiway adapters) on a "better than nothing" basis.
@@seprishere The problem is in the electric industry in the UK. Only change of the whole board to add things. Here in Germany if the board still meets the requirements we simply add that SPD to the existing board. This reduces the costs for the customer massively.
@@Marcel_Germann Most UK boards are the minimum size required, also the old ones don't really provide for SPDs.
@@seprishere Here we have a regulation how electrical installations within domestic buildings must be in some things. For example how many socket outlets are minimum for different rooms, how the cables for kitchen cooker circuit must be dimensioned (3x20A, even if you only fuse them with 3x16A). Not the VDE 0100, that is the German counterpart to the BS 7671, it's in the DIN 18015 (electrical installation in domestic dwellings). There they also demand for different size of CUs depending on the areal size of the flat or house. Also using sub-units for the circuits in the other floors and such things. Smalltest size of such a CU is three rows where the row is 12 units (one unit = 1 MCB width) wide. How many general purpose circuits are required, depending on the areal size of the flat or building. And of course dedicated circuits for appliances with a high demand. And the thing is, to have spares in the CUs and sub units for later additions. You don't change that thing like underwear. For a single room flat they demand a three row CU, so 36 width units of space. In rooms with more rooms at least 4 rows!
Seems strange that we call them SURGE protection devices, yet they protect against transient voltage SPIKES. I think of SURGES relating to current, rather than voltage characteristics? Is it just me?
These are transient spike protection devices as they can't actually dissipate much energy. Any more prolonged voltage surge such as can occur with a network fault will rapidly overheat an SPD causing it to disconnect & need replacement.
@@alanjewell9550 There are surge protectors specifically designed for overvoltage caused by network faults instead of lightning. They're different from SPDs and more expensive.
I got one installed when I had a (expensive!) heat pump put in. One area that’s not really clear is whether they should be connected via an MCB or just directly across an RCD? They can fail short circuit when they get ‘tired’ so I presume they’d trip the RCD anyway as they’re grounding the supply anyway? But some electricians are putting in an MCB…
It depends upon the SPD - some have a fuseable link inside.
Technically speaking you do not normally need any OCPD in a domestic installation (but please always adhere to manufacturers installation instructions). THE MCB is often just additional length in the circuit which can me greater inductance (the enemy of the SPD). If you can avoid the OCPD then you should. SPD's don't really get 'tired'. The manufacturing standard for SPD's (BSEN 61643) requires devices to be tested against at least 20 no exposures to each wave shape that they are providing protection against; type 1 10/350, type 2 8/20 and type 3 1.2/50 & 8/20. This means SPD's are not 'one & done' but should provide protection for many years. If you had a combined type 2 & 3 in your domestic CU for example BSEN 61643 would required 20 exposures at the large current 8/20 wave shape, another 20 at the smaller current 8/20 and then an incredible 60 no exposures at the 1.2/50 meaning a total of 100 no exposures to various transient events.
There is no end card for AFDDs.
To me it sounds like the Adt2 owner's requirement is a transitional thing until it becomes an expected expenditure: giving the electrician a "well if you insist, mate!" to a penny-pincher. I expect it will change in time, once it's become an expected cost.
I'm sure customers check the colour of the flag on their SPDs just like they all test their RCDs every 6 months and smoke alarms every week. 😂
❤❤❤🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩🇧🇩
Schneider's *domestic* boards are horrid things! So mishmashed and non intuitive, not to mention expensive . Give me fusebox any day, even Hager would do! Its amazing that a company that makes good 3 phase boards fails so epically at the * normal* stuff.
cant hear you, im at 80% with headphones on. your just way too soft, sorry, passing on video
I’m on 10% using my phone speaker. No issues hearing. Maybe get your ears checked?
@@hks-lion nope ears fine, all other tubers i follow are fine on my system headphones 70% setting (my env prevents non-headphone use), all others are loud, efixx used to be fine until 6 to 8 weeks ago, now so soft even at 100%, move to next video I'm blasted out the chair, so its efixx issue, but thats fine, I just dont watch them if this is how its going to be, I'm sure they wont give a damn if I unsub anyway.
Thanks for the feedback. 👍
@@Ressy66 10% quieter at most vs other channels but sometimes that improves the dynamic range certainly not a reason to unsubscribe 🙈 just turn the volume up a notch or two
@@hks-lion Just fired this and 3 others up on my linux desktop so I can get VU readings, -8j2-e46QwE is -0.7db, wa9H9rh8sns is - 0.6db , RrH-mCtJZO8 is -0.4db those are just 3 typical videos with more or less avg levels for all tubers I follow, the efixx video is -18db