SPD INSTALLATION IN A CONSUMER UNIT - HOW TO and THE BASICS
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- Опубликовано: 26 фев 2022
- We have often been asked about installing SPDs into domestic consumer units.
Whilst there is no legislation making this obligatory at the moment, many customers are considering this as an option to protect the many electronic items in their homes. There is a whole range of smart and interconnected devices available today and more become available with every passing day.
In this video we will show you the basics of SPD installation into a new consumer unit and into an existing board as a retro-fit.
It is not a difficult task, and, if you follow a logical method, it really is very simple.
This video is No.125 on our RUclips channel where we have videos on a wide range of electrical topics.
To see a full list of all our LearnElectrics videos, click on the link below.
/ @learnelectrics4402
You can also view all our videos by typing LearnElectrics all one word into the RUclips search bar.
Always work safely, electricity can be dangerous. If you are unsure, stop and seek advice.
This video is provided for guidance only. Every electrical situation is different, please check and ensure that you are applying this learning information to your own individual circumstances correctly and safely. If in doubt, stop and seek competent advice.
thank you so much for your explanation in so many videos you explain things so clearly and to the point you have got me out of a lot of trouble when I was stuck and didn't know the subject very well! TOP MAN! Thank you once again!
You're very welcome, glad the videos helped. Dave.
Brilliant video. Thanks David. Great tutorial well explained.
Thank you, comments appreciated, Dave.
Thanks David once again, recently installed a summer house with your previous video. Helped so much. I’m level 2 qualified so just an improver but got my work signed off by BA. Plus another fully qualified spark for your video. It’s really helped so much and you’re the don of the trade mate.
Thank you so much.
You are never JUST an improver or JUST an electrician. You have a skill at whatever level you are at and every day you are adding to that skill. Keep learning, its a great trade and its taken me all around the world on some really interesting contracts.
Good luck. Dave.
@StreamFeeds can I ask was it fairly easy to get building control to come out and inspect and sign off? What’s the procedure? I’m wanting to change my consumer unit and I’m currently re training as a spark, so would be brilliant if I could do it and get it checked etc also do building control do minor works sign offs for say if a wanted to add spot lights from a pendant and add extra light switches etc and also cracking video again dave many thanks🙌🏻🙌🏻
@@kingofthetrowel1725 I wouldn’t get BC involved if you can help it. Do the work and get a fully qualified spark to sign off for you. It cost me £500 to get stuff signed off. I found someone just after I had my first encounter with BC and would never go back to BC again now… lol
£500 to get work signed off!!!! Wowza
Great video. Had a chance to catch up on your content while I’m in hospital 👍
As always, very informative. Keep up the great work.
Thanks for the feedback. Sorry to hear about the hospital. Get well soon buddy, lots more videos to come. Dave.
I will add that it is always best practice to install the SPD on the first outgoing way of the board as this keeps the connecting leads (and internal busbars within the panel) as short as possible. The voltage that is let through by the SPD depends on the design of the SPD itself plus any voltage dropped as a result of inductive loading on the connecting leads, longer leads will mean a higher let through voltage. Also, all leads connected to the SPD should be bound for as much of their shared length as possible in order to mitigate electrical field generation around the lines. Also it is a bit of an oversimplification to call an SPD a !type 1 device" or a "type 2 device", to start with most have combined ratings these days and all SPDs will have all 3 type ratings, they will just be different ratings depending on design and installation point intent.
Thanks for your input. Appreciated.
Thanks again for your hard work so I appreciate every word you say in your lactuer
Thank you Radhi, appreciated. Dave.
Thank you very much for posting this illustrative video.
You are very welcome, glad it helped.
Pure nerdspeak! Clear as mud! Thanks
Thanks for watching, appreciated.
Very timely video. Well explained as always David.
Thanks for your time and efforts with this, always appreciated!
Thank you Francois, thanks for watching. Lots more to come. Dave.
Thanks David, its really appreciable, I never had such kind of a learning experience before. Awesome videos with great explanation....
Glad it was helpful Usman, appreciate your comments. Lots more to come. Dave.
What an excellent and well presented video
A great help for revision as well as to update our knowledge base
Very clear easy to understand and fully explained
Thank you
Glad it was helpful and thank you for watching. Appreciated. Dave.
Thanks David. What an excellent video in simple word and simple way. It is more clear than courses we attended.
Please produce more video regarding AFDD installation also.
Thank you so much.
AFDD is on the list to be done. Thanks for watching and spread the word. Dave.
Very good & easy explanation. Thank you
Glad it was helpful, thank you.
Thanks for a very informative and useful video
Great feedback Nic. Thanks.
Thank you for sharing about spd..
My pleasure. Thank you. Dave.
Many thanks dave for the hard work
Very welcome, thanks for the support.
Thank you Dave!
Thanks Tony, thanks for the support.
David I've got it. The brown line at 8:20 from main switch out live only appears to go to SPD 'E' but in practice goes "as you say" from the main switch live out up behind the SPD (not connected) directly to the live in of RCD 1 as narrated. Many thanks for an excellent demonstration.
You got it, I've just replied with the same info. Thanks for the support, appreciated. Dave.
excellent explanation on the spd Thank you
Glad it was helpful, you're very welcome.
Thankyou, incredibly clear
You're very welcome Will, appreciated comments.
Great explanation, thank you
Glad it was helpful Dominikus. Thanks for watching, lots more to come.
Thanks David - You are a good teacher - easy to understand, concise and clear with an interesting voice (to someone from London!) generous with sharing your knowledge too.
Thanks Malcolm. I can never disguise my voice. Thanks for watching, really appreciated. Dave.
VERY INFORMATIVE & CLEAR
Thanks for that, appreciated. Dave.
Thanks Dave .
well explanation
Thank you Abdirizak, appreciated.
Great info on all of these vids.
Glad you like them, thanks for the support. Lots more to come. Dave.
❤thanks for sharing your video
My pleasure, lots more to come.
Excellent explanation. I see SPDs and MCBs installed upstream of the switch.
Glad it helped Douglas, thanks for watching. Dave.
Bravo!
Thanks Stefan. Glad you enjoyed it, lots more to come. Dave.
very helpful
Glad it helped Ram, thanks for watching. Dave.
Very good video and explanation ❤
Glad you liked it, thank you for watching.
Thanks.
Thanks for watching Pradeep. Dave.
Great job dave..
May I inform you about new important topics you can make explanation videos for
- ups using, concept rating sizing
- generators
-capacitor banks
-electrical rooms design
- bus bars
-voltage drop and short circuit
- harmonics
- light calcs
Go ahead and great job man
Thank you Michael. We have a video on lighting calcs and distributed loads coming along soon. Thanks for watching.
Helpful, thanks...
You're welcome. Thanks for the feedback. Dave.
Thanks for the video. Can I loop out of the supply side of the last DP RCD in my CU with 6mm or 10mm T&E to a 32A MCB then SPD both in separate enclosure. My worry was the cable size would be less than the pre-wired tails in the CU.
Have a look at this video on cable sizing. The important thing is will the cable carry the prospective fault current at that point in the circuit, especially if the cables are going to enclosures some distance from the CU.
ruclips.net/video/3_D65-32xp8/видео.html
Your channels really good
Glad you think so, appreciated.
Hi Dave…if an installation is wired with a TNSC earthing arrangement…should there always be an reference to direct earth from the main earthing terminal eg earth rod or bonding because if there was a surge on the neutral due to lighting strike from somewhere….with a TNCS earthing the surge protector will be shunting that voltage back into the same conductor that the surge is on…..so with all this these water and gas being replace with plastic…is there a requirement in the REGS for us to make sure there is direct refer to earth in my installation…as we know voltage always wants to go to earth
Dennis, TNCS is earthed, back at the transformer. Hope this helps. Dave.
Beautiful
Glad it was useful. Dave.
David excellent Video is there an error at 8:20 "Line inputs. Your graphic shows brown line input from main switch to 'E' of the SPD your narrative says to connect brown from the line of SPD 1 line in to RCD 1 line in and then loop to RCD 2. It does not mention the shown brown line out from the main switch live out to the @e@ terminal of the SPD! Is the graphic correct as shown with live from main switch to 'E' of the SPD?
I think that's the way its drawn, E goes to the earth terminal and the brown goes behind the Devices to the line terminals. Thanks for watching. Dave.
With not Neutral IN of two RCDs from “Main Netral Bar”?
Or connect two RCDs with Neutral from SPD similar to how LINE connects from SPD to RCDs?
Two RCDs needs two neutrals. Keep the neutral and line to each RCD separate otherwise you will get unwanted tripping.
Nice explanatory video. Given the drop in price of SPDs since they first came onto the market we are seeing more of them installed now by default.
Thanks. I think it will not be long before Building Regs say that all new builds, board changes and refurbs must have SPDs as standard. Dave.
Hi, good video and a great explanation but a 230 volt ac system has a maximum instantaneous voltage to earth or neutral of around 325volts, ie the peak of the 230 volt supply is 1.414 x 230. So the SPD should not trigger until the instantaneous voltage exceeds 325 volts.
Thank you Roger, thanks for watching.
I was investigating fitting a Lewden Type 2 SPD kit and they come with a 40A MCB as standard. This seems to conflict with the advice in the video to fit an MCB that is 32A max. The data sheet indicates the cable sizes are 2.5mm/4mm as described in the video. Surely a manufacturer wouldn’t knowingly sell a kit that didn’t satisfy the regs? Not trying to sling mud at anyone, just seeking clarification and reasoning. Any thoughts …
Go with the manufacturer's recommendations always. You need an MCB that won't keep tripping every time a big spike arrives, but not too big that it never trips, Conversely, you don't want a 6A breaker that is always tripping.
32A and 40A are in the same ball park. Thanks for the input. dave.
Sorry in advance if its a stupid question - will the MCB powering SPD not get overloaded as everything else is powered through the SPD line terminal?
It looks to me as it'll keep tripping on overload, is there something missing in the diagram? Or m I missing smth obvious.
The SPD just looks at what passes across its terminals. The current for all the circuits does not go through the SPD, just passes across the top. Only when a spike of over-voltage arrives does the SPD suck that over-voltage through itself. The rest of the time it just watches. Think of a conveyor belt with small boxes on it. As long as the boxes are small, we let them go past us. If a big box comes, we take it off the conveyor belt and put it behind us.
The mcb protects the SPD from prolonged over-voltages. Hope this helps.
I agree, it looks like the entire CU current will flow through the MCB
Hello David from Bosnia, I have two questions
1. Do I need MCB 32A type B or type C for the SPD?
2. Is this good = from Main Switch to MCB 32A type B then to SPD and from SPD to RCD, (MCB is protecting all from Main S.)
what do you think about this?
I would use a type B to protect the MCB. The SPD should be immediately before the main switch or immediately after it. Some pre-loaded consumer units come with the SPD before the main switch. The RCD current is NOT going through the SPD, all the SPD is doing is monitoring the voltage on the bus bar for spikes.
Take a look at this other video of ours on SPDs, it will explain better.
Use this link ...
ruclips.net/video/CCZJ0CPOR2U/видео.html
Hi. Sorry for stupid question. But if you r board has an 80a supply for example and your connecting rcd 1 and 2 from top of SPD which goes through the 32a mcb which you’ve shown you’ve limited your board supply to just 32a? That correct?
No. The SPD is only monitoring what goes across the top of it. The current to the RCDs and the rest of the board does not go through the spd. The SPD is effectively monitoring the bus bar. The 32A mcb is a recommendation to limit any spike current to 32A to protect the spd. Hope this helps.
@@learnelectrics4402 Hi. Only reason is if you look at your picture of the DB you have a copper bus bar link from main switch into the bottom of the 32a mcb,then from the top of the 32a mcb which then goes across to the SPD and also the RCDs. So surely if it’s all through that 32a mcb that’s maximum your board will be pulling. I maybe be stupid
In the diagram at 8.20 I first thought that the whole installation was running through that 32A SPD breaker, but if you look at the live on the main switch, a brown cable comes from that, to the live on the SPD and to the two RCDs. So the SPD is in parallel with the the main switch and both RCDs.
Hello sir, if my appliance is working 240v max then if i install 275uc type1+2 spd.... Isit better than other spd thatwith type1+2 330uc specs spd?
Arun, you would need to compare the data sheets for both SPDs and decide which one suited your particular needs best. Thanks for watching. Dave.
Great video but it’s mainly the cheaper suppliers of SPD’s that require an MCB back up some don’t and free up an additional way on the board.
Thanks for the extra info, thanks for watching.
Great video thank you! I've been told you can't fit an SPD on a TT system please can you explain why if it's true and if not do you have to do anything different for a TT system . Thank you
I’m not an electrician so take this with a grain of salt but: With TT systems and SPDs I believe you have the same problem that you always have with TT, i.e. there won’t be enough current flowing to trip circuit breakers in the event of live to earth faults. On TT I believe you can use a CT2 SPD without any further protection than the circuit breaker and that you can use a CT1 SPD if and only if there’s an RCD before it. If you are installing an SPD yourself make sure that you keep the leads very short ;-)
Thanks for the question. A TT system has a high resistance path and will not respond to surges the same as a TN system. See Jonathan's reply below.
Thanks again Johnathan. Great response. Dave.
@@jonathanfox1105 thank you . I'm new to this and wasn't sure what's best practice.
Thanks David...Good video. Quick question... If the MCB protecting the SPD from a longer duration surge, was to trip, would this not just send the Surge back into the installation?
I would have thought it better to let the SPD take all the surge and I wouldn't have thought the MCB was a good idea???
All devices can fail over time and if the SPD fails short circuit then you are risking fire without the circuit breaker (or taking out the main cut out fuse).
Thanks John, see Jonathan's reply below. Thanks for watching. Dave.
Brilliant answer Jonathan, thanks for the support. Dave.
From repairing power supplies from africa where there is a lot of lightning, MOVs frequently fail short circuit. If there is no overcurrent protection this could end badly.
Hi Dave, as always, thank you very much for your work. Do you recommend an online course for the C&G 2382-18 (in conjunction with your videos) and then sitting an 'in-person' exam post-learning? And if so, can you recommend any specific website for this? Many thanks,
Thanks for the feedback Kevin. Everyone learns differently. Some do well with on-line and others learn more with face to face. NAPIT and NICEIC do some good courses. If you go to an independent trainer, always visit and check them out BEFORE parting with any cash. Most are good trainers but there are some horror stories out there. And visit at least three centres before deciding. Its worth it to get the right training centre for you.
Good video but you missed the information about how long the cables should be .
Thanks Andrew, thanks for watching. Dave.
Hi David
Good informative video however I think it’s not suitable for TT installations and T1 SPDS
on a TT installation a T1 device has to be located as close to origin also the SPD would usually be installed prior to RCD as operation of RCD would prevent functionality of SPD. In addition to that the SPD will also have to be fitted with larger tails and cpc conductors and an OCPD usually rated at 63A or greater depending on manufacturer requirements.
I think it would benefit views you cover TT requirements in greater detail or at least inform them that they require greater consideration.
Good comments. Thanks for the input and thanks for watching. Dave.
Is the surge module the vaiestor?
The varistor part is contained inside the SPD and this will trigger when a certain size surge is detected.
What type of SPD should be installed in the main electrical cabinet of a residential home?
In the Dist bd is usually a type 2. Thanks for watching, appreciated, Dave.
@@learnelectrics4402 thank you very much
A little confused as to why the position of the spd doesn't seem to matter, but why do most innstallers and manufacturers now place the spds on the board before the main switch
There are always new methods. As long as the SPD is installed where it can monitor effectively it will do its job. Thanks for watching. Dave.
good demo and well paced
Thank you, appreciated. Dave.
Is the whole installation now protected by only a 32amp mcb?
No its not, the 32A breaker is just protecting the SPD. None of the current for the other devices goes through the SPD, it just watches what goes across the top of it. Take a look at this other video on SPDs, it will explain exactly your question. Thanks for watching. Dave. Here's the link...
ruclips.net/video/CCZJ0CPOR2U/видео.html
Maybe I`m not quite getting this, but looks to me like the diagram shows the entire installation being supplied through the 1 32A MCB and the SPD? That can`t be right
The mcb is just protecting the spd from overcurrent. Thanks for watching.
Can we connect output of type 2 spd to neutral instead of earth?
There isn't an output on an SPD. Just Line, Neutral and Earth, which should go to the appropriate terminals. Hope this helps.
@@learnelectrics4402 Hello thank you for the response. By "output" I mean the line that will connect to earth bar
If the consumer unit is fitted with RCBOs is the installation the same?
Yes. The RCBO will directly replace each MCB and negate the need for RCDs.
In the video power drawing if the 32amp mcb trips no power to rcds
There fore the whole installation is running off a 32 amp breaker
Or am I blind
The 32A breaker is there to protect the SPD only in case of overload to the SPD. The house current does NOT pass through that breaker, the voltage and current to all the circuits in the house just goes across the top of it so that the SPD can monitor the house electricity for spikes. Hope this helps. Dave.
@learnelectrics4402 check your drawing
@@tonylockwood6370 no, he’s done it right - but if you pause video and look at it, it can appear wrong!
both main RCD’s are supplied by the last cable installed - the brown conductor that comes out of the bottom of the main switch and runs up BEHIND the SPD - just unfortunate that if you pause it appears to connect in with the SPD ‘L’ connection (red loop at top)
@@mikedowney6777
You are right.
@@learnelectrics4402 thanks for the clear way it was explained
There is a lot of controversy over SPDs and AFDDs mainly the cost of the them and weather they are really needed in domestic installations?
I have asked many times a simple question but no one has come back with an answer or area unwilling to answer because the question throws a spanner in the works ?
So I try again , if lightning hits the main transformer at the end of your road or the overhead power lines , why is it a problem ? Ok you could loose the power in the hole street but how would it effect our house? Surely the short lived surge will only get as far as the DNO cutout witch will blow ? And the surge can’t go any further,
Therefore an SPD is a pointless waste of money? Personally I think it should be a personal choice if a home owner want it or not, to make them mandatory is the wrong thing to do how many people can afford to have them not a lot.
Fantastic video very interesting and informative as always Dave 👍👍👍👍❤️
Yeah it's an interesting question.
Makes me wonder how many surge protected devices basically do this in / on circuit?
e.g. you could make a plug in device that does this at a socket and I wonder if those devices are actually doing this when they are plugged in.
And as you say justification wise, I've seen two times when power spikes have clearly killed equipment and both we're direct lightning strikes to the building.
Outside of this is would be very hard to prove one way or another if this device is actually doing anything.
Anything I need protecting is on the other side of a UPS or at minimum a SPD gang or plug.
So yeah double checked, most SPD power bars / extension leads do this at the plug so if you have one of those plugged in anywhere guess what you already have :)
So if you want more protection just plug in more power bars.. ;D
Yes, lots of interesting discussion. The day will come when Building Regs say they must be fitted. I know the insurance companies are interested because they are insuring tech equipment and SPDs will reduce their liability. Good point Sean.
Lots of discussion Dave. No-one has a definitive answer but I feel they will be compulsory on new builds and board changes in the coming years. Thanks for the input. Dave.
Thanks Dave.
Why Neuteral 1 , 2 and the main are not connected together?
The RCDs function by having separate neutral bars. Hope this helps. Dave.
what is the differnce between type 1 snd type 2 SDPs?
Several differences Imran. the amount of current and voltage they can handle. Type 1 are generally for protection outside the property where a lightning conductor is installed. Type 2 are usually installed at the installation source where it comes in to the property and where there is no lightning protection.
What's the point of mcb for that spd??.. if that trips all protection is gone
The mcb protects the spd. If that trips the spd does not catch fire but all the circuits are still enabled and protected by their own mcb.
Have a look at this video, it answers your question perfectly.
ruclips.net/video/CCZJ0CPOR2U/видео.html
@@learnelectrics4402 well there are out there SPDs which doesn't need protection, i.e. they are rated for 100A already. Installing an MCB in front of an SPD will render that SPD installation pretty much useless in the event of a surge especially when the surge protection is needed the most.
So yeah don't use the brand which needs overcurrent protection
According to this all the power is going through the spd?
No, not at all. The SPD is in parallel with the other devices.
On the final stage of the connections the live appears to connect to the Earth of the SPD
Just the route the earth is taking behind the components. Great that you are studying it, appreciated. Thanks for watching, Dave.
👍👍👍
Thanks, appreciated, Dave.
Surprised they haven't got a check 6 monthly spd sticker in the new regs
Don't make them bring out another Amendment - please. Thanks for watching, appreciated, Dave.
Great little video BUT slight problem with your connections! You show the live feeds to your RCD's taken from the supply to the SPD, this is incorrect as the whole installation would be fed via the 32A MCB feeding the SPD! The RCD's need to be fed from the main switch not the SPD....
The 32A mcb is aN IET recommendation to protect the SPD as in theory it could take an unlimited amount of current until it pops. Hope this helps.
@@learnelectrics4402 No you miss my point, I know you need a 32A MCB to feed the SPD but on YOUR diagram see 8:20, you show the feed to the 2 x RCD's as coming out of the live in to the SPD which in turn has been fed from the 32A MCB, this is incorrect as the whole installation is fed now via the 32A. The RCD's need to be fed before the SPD MCB. :)