+John Ward 2 related Areas worthy of Further video in my view:- (1) When is a circuit a distribution-circuit that may only require 1sec (TT) or 5 sec (TN) disconnection time [>32A ?]. [presumably the TT case is where you also use a 100mA S-Type RCD as well...]. (2) Selectivity between MCBs It seems, in some circles to be accepted to use a C50 to feed a downstream B32 (e.g. submain to garage with electric-car fast-charging-point), and similarly to use a C32 to feed downstream B16 (e.g. feed to outbuilding with multiple socket-circuits). HOWEVER this is seemingly not 'guaranteed' and depends on the particular combination of devices and the exact fault-impedance and so-on and so-forth. When is a switchfuse with BS1361/DNO style fuse instead of a circuit-breaker better to feed a submain, anyway...? Discuss: What MCB-selectivity is actually 'good enough in practice', what 'passes inspection', etc...?
@Sarcastix76 жыл бұрын
Very informative. I'm studying Electrical Engineering in college and we went over cable sizes for circuits but didn't discuss the impedance of the circuit. So my understanding is you would need to have the correct size cable for the rated current but you might also need to increase the CSA to bring the impedance down to the levels specified in the guide to ensure magnetic tripping in the time allowed. Of course that doesn't really help if the circuit is already installed.
@simonparkinson10536 жыл бұрын
Oblivion You understand correctly! It's beneficial to have actual supply parameters and detailed specs for the load and circuit breaker. Generalisations such as Ze= 0.8 ohms for TN-S and Type C magnetic being 5-10x might imply your circuit is non compliant. But with detailed specs and measured values you would have a definite answer.
@Sarcastix76 жыл бұрын
Simon Parkinson Makes sense. Thanks for the reply :) Every little bit of knowledge from people that know first hand is very helpful.
@johnmac80846 жыл бұрын
Another great video JW, I was a bit hazy on MCB types, but you just nailed it
@ianm1446 жыл бұрын
Only ever retro fitted type C twice, may years ago.Once when I added 4 more magnetic powered halogen lights to an existing circuit of 8 lights. The breaker would occasionally trip when the 12 lights were turned on. Changed to type C for this circuit and all was fine. Should really swap back to type B as over the years many of the in ceiling transformers have been replaced with modern electronic units.2nd place fitted was house entry lighting circuit. When using ye old tungsten bulbs the cold air rushing in from front door would mean very short life for the entrance hall way bulbs, generally bulbs blowing and taking out the breaker. This circuit was also the garage light circuit where the breakers were located, as well as any easily accessible light switches from front door. Thus one had to fumble around in the dark, in the garage to reset the breaker. Changing this to type C meat when bulb blew the breaker no longer tripped and other lights on the circuit worked fine. All not necessary now using first CFL bulbs and now LED.
@bobbyleigh96862 жыл бұрын
What a fantastic video. Thank you so much for this John. very informative and very well broken down and explained. Great work :D
@aogulla6 жыл бұрын
Nice video. A brief mention of DC circuit breakers and why AC breakers should not be used in DC circuits would be helpful.
@muzikman20086 жыл бұрын
Excellent video Cheers JW
@aroncells31206 жыл бұрын
Great video, your knowledge and ability to teach this is very appreciated thanks
@manickn68196 жыл бұрын
Excellent video. This was on my to research list so I saved that time watching the video.
@CoolJosh3k6 жыл бұрын
Can you do some vids about surge protectors?
@BipolarShango6 жыл бұрын
Your videos are soooo good. Thanks.
@ansarawan4 жыл бұрын
helpful and informative. Great lecture JW
@islashiraz91875 жыл бұрын
Thanks Mr ward for all of your informative videos, without watching your video, I couldn't progress in my electrical installation course. Thanks again
@jamesanimashaun16614 жыл бұрын
Simple,and precise
@johnjgcork4 жыл бұрын
Thank you John, as always I learn so much from your presentations. I teach physics to Electrical apprentices among others in various career paths, but I find many apprentices have no real desire to grasp the science behind Electricity. I recommend your site to many. I always hope they learn as much from from us, to improve their own safety as much as the end user. Keep up the good work.
@ahmedalazazi2895Ай бұрын
Great video ❤ Can you please tell me what are the criteria of MCB selections from type point of view Many thanks to you
@mayureshpatil79724 жыл бұрын
Very nice & Crystal clear VDO. Can you please explain why MPCB used in Industry and disadvantages / Advantages over MCCB's.
@GarryL2776 жыл бұрын
Can you please do the same type of video for dc power for solar and battery installs or is it the same as A/C
@jwflame6 жыл бұрын
Types B,C etc are the same, however MCBs for DC are not - if using on DC you need to get ones which are designed for DC, as using AC breakers on DC will quickly destroy them.
@bjornroesbeke6 жыл бұрын
In Belgian residential installations, circuits are protected by C-curve breakers. B-curve breakers are rare. Would you argue this is less safe?
@jwflame6 жыл бұрын
No problem with safety as long as the impedance is low enough.
@simonschertler30346 жыл бұрын
Here in Austria and Switzerland the C Type is also the commen Type for "normal" circuits.
@simonparkinson10536 жыл бұрын
Bjorn Roesbeke I understand the reasons behind that where socket outlet circuits are 16A radials due to the rating of the outlets. Some equipment with high inrush current will cause nuisance tripping of a B16, but not a C16. Where the norm in the UK has been ring finals with B32 MCB, the instantaneous trip values C16x10 and B32x5 are both 160A. In the UK we tend to use 20A rather than 16A breakers on socket outlet radials due to having the additional protection of fused plugs with a maximum of 13A. Then it's up to you as the designer to decide if you need B or C breakers, respecting the maximum loop impedances for proper protection.
@dannymort72626 жыл бұрын
Cheers JW. Great video. Is there any chance of touching upon mccbs, in the future with some information on maximum zs values when the device has an adjustable magnetic and thermal setting
@malachygallagher49363 жыл бұрын
Hi John Watching all your videos! There are brilliant! Would like to see more on earth rod measurements & calculating current flow in the event of a fault with neutral/earth! Thanks!
@simontay48516 жыл бұрын
Why type K and Z and not just type E and F? Also what do the letters stand for in TNS and other system types?
@johnburns40173 жыл бұрын
MCB's are to protect the cable. They prevent the cable from being too hot or overheating, which may cause a fire, so indirectly protecting people. A cable constantly being too hot will deteriorate its own insulation. Current travelling excessively through a cable it was not designed to cope with, will heat the cable. When the current travelling through the cable is over a safe limit the MCB senses the current, then if the maximum current is reached for the cable, it automatically isolates the cable it is protecting. The type B, C and D MCB's are to prevent _nuisance tripping_ caused by momentarily current surges.
@pramodgavit76662 жыл бұрын
Mr Jhon At what current Btype 32 Amp and C Type 32 Amp MCB start triping.
@davidfildes98266 жыл бұрын
We get some violent thunderstorms here on our farm in western southern Thailand. Couple nights ago there was a local strike and fired the house RCD with a bang but not the one serving our well pumps about 10 meters away in a box on the service pole? Can you offer any explanation.
@michaelcostello69913 жыл бұрын
At 13:35 Table 41.4 there are 2 rows of Zs values for MCB type D for 10In and 20In. The 10In row of Type D has the same impedance values as a Type C MCB. Please explain. Also i am confused by 0.4 and 5 seconds. I thought all the MCB's trip almost instantaneously ? This is really confusing.
@karoly3654 жыл бұрын
Bit confused at 14:06. On one hand you are choosing a circuit breaker which should trip at a different time, but on other hand you are choosing the earth the fault loop impedance such that they all trip at the same time. What am I missing here? Are we talking about different scenarios?
@jwflame4 жыл бұрын
The difference is between moderate overloads and a short circuit fault. All of them need to trip near instantaneously if a short circuit fault occurs (which is where the loop impedance is important), but for some applications overcurrent of a short duration may occur in normal operation, such as when starting a motor. For a motor as an example, the circuit breaker needs to be selected so that it will not trip for the high starting current of the motor, but the loop impedance needs to be low enough so that it will trip if a short circuit fault occurs.
@michaelcostello69912 жыл бұрын
If it did not trip on a fault current due to high impedance it would still trip eventually on overload i assume ? But the cables might be over heated before this. Is that correct ?
@jwflame2 жыл бұрын
Yes - the overload part relies on a metal strip heating up so cables could overheat if that was the only thing which disconnected a short circuit fault.
@hygri3 жыл бұрын
Very informative, thanks. One odd thing is the vertical (magnetic) part of the MCB graphs in Appendix 3, for example graph (and associated table) 3A4 and similar to your example in 21:04. 18th ed. Appendix 3A4 shows that for a 6A type B, trip time at 30A will be anywhere between 10ms and 12s (or 10ms to 5s in the associated table). If that is in fact the case, how are we to design to achieve 0.4s disconnections from Appendix data? Of course the table 41.3 defines a Zs value for 0.4s, and these data correspond to 0.95x the calculated impedance to achieve the breaking current shown in appendix 3A4, but how can we state 0.4s or better when appendix data suggests 5s (or 12s in the graph) or better, not 0.4s or better? This isn't the case for type D, which are specified separately for 0.4s and 5s. Seems there is a disparity between table 41.3 and the way data is presented in Appendix 3A4.
@Mr2Xri3 жыл бұрын
Hello, if we have a B type MCB (22:00) and we have a 4times the rated current the magnet will trip between 0.02sec to 1.5sec approximately?
@danielalarcon29823 жыл бұрын
we have 110v phases in my country, I want to buy a 40A MCB, but I noticed that everybody sells these 230/400 volts MCB's no 110v breakers, so it would work properly?
@jwflame3 жыл бұрын
Yes they will work, they are current operated, the voltage isn't particularly relevant as long as the maximum voltage isn't exceeded. Check with the MCB manufacturer to confirm the voltage range.
@laernulienlaernulienlaernu89535 жыл бұрын
The majority of breakers found in domestic installations tend to be B type, whether or not this is by design or by the fact that that’s what comes with the fuse board I don’t know
@jensschroder8214 Жыл бұрын
we used to have H16A circuit breakers in the house. The problem was that the microwave regularly triggered the circuit breaker. The electrician said these were already obsolete and all converted to B16A. Then there were no more problems.
@mirochen8564 жыл бұрын
Dear Mr. John. Would you like to help me tell some details information about Z type. As we know the Z type instantaneous tripping range is from 2In to 3In. But normally MCB make the short-time delay test is 2In or 2.55In. So now we meet the problem is the short-time delay test almost equal to the instantaneous tripping test. Would you like to tell me some details information how to use the coils and core springs to solve the prblem? thank you very much.
@michaelcostello69913 жыл бұрын
Are these Zs values the same for RCBO's . With type D is it written on the breaker if its 10ln or 20ln
@jwflame3 жыл бұрын
Yes, they are the same. The overcurrent part of an RCBO is the same as an MCB.
@yanizrulyanizrul58145 жыл бұрын
Hi John. I am having a TT type system. With reference to minute 13:00 of this video, the table is suggesting a system impedance which is not achievable by a TT system. How do we then go about this? Is the table not applicable for a TT system. Or will therefore all TT system require a RCD for the MCB to work? But then the selection of the MCB type could be of any kind if the impedance value is irrelevant for a TT type system. Appreciate your help..
@jwflame5 жыл бұрын
That table and the rest of 411.4 only applies to TN systems. TT are covered further on starting at 411.5 RCDs are almost always needed to ensure disconnection on L-E faults for TT systems. MCBs are still required to cover faults between L&N and overloads, as RCDs do not detect those.
@fa61516 жыл бұрын
Thank you
@muntakaabdulrauf40566 жыл бұрын
Thanks very much for your videos , but my question is when am having high readings on Zs , what is the solution?
@motorone53015 жыл бұрын
Are the Zs values high on each circuit you test or certain circuit's?
@derektodd41266 жыл бұрын
What breaker would you recommend for 4 x 100w 12volt solar panels in parallel ?
@Jako19876 жыл бұрын
Derek Todd You should have them in series (if your solar panel control unit accepts enough high voltage)
@jwflame6 жыл бұрын
Ones that are specifically designed for DC - using AC breakers on DC will destroy them.
@rod93116 жыл бұрын
I agree with Jako, 48V series @ 8.3Amps or 12v at 33.3Amps. DC breaker as JC said.
@denischarette47445 жыл бұрын
Thank you. Are RCD`s and MCB`s coordinated? If there is a heavy L-E fault on a circuit, do I lose only this circuit, or the whole busbar because of a faster RCD?
@jwflame5 жыл бұрын
Not usually. A high current L-E fault could result in either device disconnecting, but usually it's the MCB as they are much faster on high current than an RCD. One RCD for multiple MCBs is a poor design anyway, if it's undesirable for the RCD to disconnect multiple circuits then individual RCBOs is a much better option.
@jsg88034 жыл бұрын
hello John Ward Yours video is highly helpful however i encountered a MCB from Brown, Boveri & Cie (BBC) which is a very old defunct company which is of Type L and that type of classification is very old and i cant find any discription of it anywhere do you have any information about the same???
@jwflame4 жыл бұрын
www.galco.com/techdoc/abbg/s252-l6_gi.pdf
@jsg88034 жыл бұрын
@@jwflame the pdf was very helpful thankyou very much but would it be correct to assume this L type breaker comes under 1,2,3,4 classification???
@denischarette47445 жыл бұрын
John Can I use a breaker that is only thermal? Let`s say a 40A breaker and a current of 420A. Would the bimetallic strip bend very fast and trip in less than .5 sec., or would the strip be melted?
@jwflame5 жыл бұрын
No, thermal is too slow to disconnect on short circuit faults.
@NigelsModellingBench3 жыл бұрын
So.. I have a B16 in my consumer unit feeding my Garage through a 2.5mm cable. On occasion, my compressor will trip the house fuse, even though I have a 16 amp fuse in the garage? If I fit a C type breaker will this cure the issue safely? I was advised by a "mate" to fit a 20A fuse but I feel that may be not the done thing?
@jwflame3 жыл бұрын
A type C circuit breaker may resolve the tripping problem, but the circuit and supply must be tested first to ensure the impedance is low enough. The maximum impedance for a type B is double that of a type C, so it's entirely possible that a type C may not be permitted on that circuit.
@NigelsModellingBench3 жыл бұрын
@@jwflame thanks John.. I'll get it tested and go from there.
@jijikocharekar2112 жыл бұрын
Nice👍
@subashadhikari55875 жыл бұрын
Is the curve type of breaker is dependent on the length of cable.i
@jwflame5 жыл бұрын
In a way. Each type has a certain trip current to ensure disconnection, and therefore the impedance of the circuit must be below a certain value to ensure the fault current is high enough. Circuits that are too long will have an impedance that is too high, so the length must be kept short enough to ensure the impedance is low enough.
@bobcocampo4 жыл бұрын
What is the temperature rating of the lugs?
@jwflame4 жыл бұрын
Usually 70C, same as PVC insulated cable.
@erickjuma62116 жыл бұрын
Hi l have just seen a consumer unit where 6 combined instant shower heaters each having a rating of about 15 amps are connected to only one type c 32amp mcb. Is this correct or safe!!!???
@enycenyc31446 жыл бұрын
The breaker is thee to protect the wiring. Essentially, if the wiring is all rated for 32amps (i.e. about 4mm or more in most cases) and the impedance (Zs) at the far-end is low-enough for C32 breaker, then thats' fine. This arrangement does mean you should expect the MCB to trip if you use more than 2 of the showers at once, which is probably fine. The shower-units themselves may mandate a maximum rating of breaker. See video on "diversity". kzbin.info/www/bejne/jaKTpoJ6rtWUfas
@michaelcostello69913 жыл бұрын
Why does it just give Zs values. What about R1+Rn as you mention this must be low enough also for breaker to trip
@jwflame3 жыл бұрын
Impedance between L&N will be the same or lower than the earth loop impedance, so if Zs is low enough, the other one will be as well. However it's important to confirm R1+Rn and to also measure impedance L-N where possible, as problems such as high resistance or open neutrals can occur.
@michaelcostello69913 жыл бұрын
@@jwflame Thank you very much. I was looking for this explanation.
@robertgemmell14852 жыл бұрын
👍🏻👌🏻👌🏻 cheers.
@thrunsguinneabottle30665 жыл бұрын
I doubt that there is any upper value to the tripping range. It would mean that if you got beyond this colossally big value, there is no result (except to melt something).
@jwflame5 жыл бұрын
The upper limit is the breaking capacity, which is normally printed on the device in a box, such as 6000 or 10000. Fault current exceeding that may damage the circuit breaker or weld the contacts closed.
@tarassu4 жыл бұрын
Actually Type A exists. I've holded some MCB-s that are Type A. Extremely rare.
@tarassu4 жыл бұрын
John, I can send you a photo of one I've held :)
@jwflame4 жыл бұрын
Yes please - email and other contact details here: www.flameport.com/youtube_channel_info.cs4
@tarassu2 жыл бұрын
@@jwflame Sorry, I forgot. I've sent the email right now.
@seekter-kafa3 жыл бұрын
how many videos must i watch for someone to properly explain 3 fucking numbers on a MCB???
@tesfayeayalew20844 жыл бұрын
HIoT
@tonezoneuk6 жыл бұрын
How can a 6A type B still be a 6A if it is type C or D. Surely, it's not a 6A breaker anymore. Does not compute.
@barrybritcher5 жыл бұрын
Yes. It's just got a higher surge tolerance before it trips
@m101ist3 жыл бұрын
The 6AMP's rated MCB is for the thermal cut off which is the same for B, C,D rated. Not the trip current.
@raymonddinga62613 жыл бұрын
Talk alil bit slower..
@jamie_d___ Жыл бұрын
I love Electrical information , I enjoy it so much I'm watching this at 4.22am In Australia , before going to work in the electrical industry , purely for enjoyment . This is me coming out , as a geek .
@chickennoodles36749 ай бұрын
Its 4.32 am here in nz😂
@johnmac80846 жыл бұрын
If you could do one on RCD types as well (if you haven't already?) that'd be great, thanks JW
@paulne96 жыл бұрын
Just checked mine and they are all type 2 on a t t system from over head wires as the house is over 200 years old which i had rewired in 1989
@stefantrethan6 жыл бұрын
Are you sure about the RCD not helping? I believe there is some rule here that says if you provide RCD protection you don't need to meet the impedance for magnetic tripping. The reasoning is the RCD protects against a dangerous touch voltage and it is not necessary to switch off instantly, the slow thermal protection is good enough for fire protection. I'm not 100% positive this rule is still active but I can investigate. It would apply also to plain old thermal fuses, which have no magnetic trip, when combined with an RCD.
@jwflame6 жыл бұрын
RCDs will help for L-E faults, but will do nothing if the L-N impedance is too high.
@stefantrethan6 жыл бұрын
I'm aware of that, but my thinking was that the thermal cutout will eventually get it. The requirement for breakers to switch off instantly comes (also) from preventing dangerous touch voltages in case of a L-E fault, which the GFI would prevent. There seems to be some discussion over here if the requirement to switch off within 0.4s is only applicable to L-PE or also L-N. One way to get around this problem might be to use fusible element type fuses instead of breakers in combination with a GFI to achieve higher inrush current tolerance in high impedance circuits.
@stefantrethan6 жыл бұрын
VDE100-600 says if there is a GFI you generally don't even have to measure the loop impedance, make of that what you will, I'm not much further towards understanding it. The differnt standards in each country don't exactly make things easier.
@simonschertler30346 жыл бұрын
Since 2017 in Germany Z_I has to be measured and Riso has to be tested between L&L and L&N. The Others important fact is, If the RCD ist used for "Basisschutz" (earth fault L-PE) or "Zusatzschutz" (earth fault L-Person) ...... In some cases the required tripping time (L-N) can be 5s instead of 0,4s. Because of is wird Situation i allways choose the Type according to 0,4s -> Z_I
@IrishHitman796 жыл бұрын
Very informative... Any chance you could explain with Ib and In etc... rated current and breaking capacity mean while you are on the topic. Thanks.
@AL_O06 жыл бұрын
Actually in Italy we use mostly type C pretty much for everything, I don’t know why
@florind.57114 жыл бұрын
Same in Romania.
@richardlang21854 жыл бұрын
Dear John. Thank you for making all those great videos. You have great electrical knowledge and I do very appreciate it. I need to mention one comment. BS7671 doesn't provide final Zs values for Circuit Brakes. All values have to be multiply by 0.8 correction value. On Site Guide have already corrected those values compared to BS7671. Kind Regards Richard
@gbelectricks6 жыл бұрын
Great explanation again John. Please could you do a video on mccb’s. Thanks
@Marcel_Germann6 жыл бұрын
Thank you, that video is great! In addition: In Germany there are two other types available. You've already mentioned the type K, this was a common type here for workshops with large machines. K stands for Kraft (power), and is one of the old german types still available. The other ones were: H for Haushalt (household), manufactured until 1976. Magnetic: 2 to 3 times. Thermal: 2.1 times (up to 4A) 1.9 times (6 to 10A) 1.75 times (12 to 25A) 1.6 times (more than 25A) So it's for high impedant grids. It was replaced by type L, which was used here until 1990 before it was replaced by type B. But L is still available as circuit breakers for the replacement of Diazed fuses. In this case the housing is round and it's having an Edison thread. L for Licht (light), or later Leitungsschutz (cable protection): Magnetic is the same as B, thermal is the same as H. Picture of a screw-in MCB with Edison thread: i.ebayimg.com/00/s/NzQyWDEwMjQ=/z/-koAAOSwwBha1XbF/$_72.JPG
@joshb9657 Жыл бұрын
If the installation was say 6 type C MCBs protected by an RCD, would the RCD help with the failed Z's readings if there were any ☺️
@michaelabiera6 жыл бұрын
Good video. How can I get the handbook that you're using? And website where I can purchase it?
@jwflame6 жыл бұрын
Small on site guide: amzn.to/2Je3CxY Large BS7671: amzn.to/2Jf8umv Links also added to the video description.
@michaelabiera6 жыл бұрын
John Ward awesome thanks. Keep up the videos.
@bryansmith14225 ай бұрын
Excellent information thank you ! 😊
@kawserahmed6713 жыл бұрын
How Can I Get English Mediumboo?
@paulmorrey7336 жыл бұрын
Thanks John
@russellfreestone8580 Жыл бұрын
Once again,thanks
@arjun-iv4wr Жыл бұрын
Thank you John
@marekdesign9854 Жыл бұрын
thanks John
@uittyman2 жыл бұрын
Great content your a beam of electrical light for the curious mind. An enthusiastic thumbs up 👍
@ningis216 жыл бұрын
Is there a way we could reduce the "Z" in order to install a type "C" or "D" breaker when Zs is none compliant?
@mirochen8564 жыл бұрын
Hi, Ningis21. If normally you use the "Z" type MCB?
@alistercarmichael49902 жыл бұрын
Use bigger conductors for the circuit. The majority of Zs is provided by the supply though.. in a decent installation, so you are always limited to the installation loop as a maximum current. Most domestic circuits in the UK can't meet the psc or pfc for type D devices.
@Kenneth_H_Olsen5 жыл бұрын
It is said. the trip sequence is base on IN Ampere multiplier of currents, denoted as I1 IN *1.3 (test current, no trip), I2 IN * 1.45 (garantees opening of circuit witin 1 hour) Both of these are Thermal and Bimetallic . I4 IN * 5 (electromangetic holding current, no trip), I5 IN * 10 ( el.mag garanteed to open in 0.1 millisecond) . The different characteristics A (sensitive electronic AC), B (household appliances), C (motors, large heaters) . The A, B, C, D- Char have different factors to multiply into IN (nominal Ampere), and match the power leth thru, during smallest (I2) and largest (I5) short or failcurrent, considering the cables crossection and lenght, how they are laid. the amount of load . You have to obtain A^2 sek, that is the mass of the let thru energy once it trips. thats done in the Z-line (Z-loop) calculation or measure. You select a match the short circuitbreaker max can handle, 10kA. The maximal let thru Ampere (I5) is calculated . t = k^2 * ^2 / I^2 finding the splitsecond its required to open. Then I / IN , (I5 maybe IN * 10 = 320A) . k= table specific konstant for conductor type AL or CU and insulation PVC or PEX. PVC has halogenes and chlorine deadly gases when it fumes and is hot, PEX and EPR is Halogene free. S = crossection, remember each crossection has to be calculated, if there is a reduction of crossection along the circuit), I is the Ampere of the Load. Then Match the current multiplyer fits the curve characteristis on the fuse diagram, PLSM, PKPM, dRBM (xdigital), Acti9 C120N, IC60 RCBO. And added safety is the SPD (surge protector) protecting from lightning strikes and atmospheric inductions, SPCT4, IPRD. The SPD is demanded infront of of any new sub distribution cabinet. Type 1 coarse, Type2 middle, and Type3 for finer undulations of stray currents and suggested for data and sensitive electronics on AC .
@livrad70082 жыл бұрын
merci 🌹🌹💚💚
@michaelcostello69913 жыл бұрын
Why is TNS Ze a high value up to 0.8 ohms ? Is the supply earth conductor smaller than the supply neutral ?
@andrewturpin19944 жыл бұрын
In my industry, the caravan industry we us type B and type C, predomantly it is type C
@dayanandsp13764 жыл бұрын
it's Good understanding 😜 for bad Electrical Engineer's 🤘
@bborbelyimre3 жыл бұрын
Dear John, this video is graet. Regards, from Hungary
@stevensidor71812 жыл бұрын
I wish I had a brain like you, very good information 😁
@szilardtoth81183 жыл бұрын
And a Hammond L solemnly sits in the background
@sohailjanjua1233 жыл бұрын
Hi , Ilike your lecture.Thanks
@jonathan.h2 жыл бұрын
Great video, you say there is no Type A, but what are the type A C and Type A B i've seen on sale? is there a video on these?
@jwflame2 жыл бұрын
RCBOs, which are a Type A RCD combined with a Type B or Type C circuit breaker.
@jonathan.h2 жыл бұрын
@@jwflame thanks John. Do you have a video about DC leakage and RCBO types?
@phsparkytoolslinger18976 жыл бұрын
I see some with type L, what is that for?
@bobcocampo4 жыл бұрын
What type will you recommend for Airconditioning unit
@jwflame4 жыл бұрын
That depends on the specifications of the AC unit.
@shazbash39786 жыл бұрын
nice top where can i get one
@wasimullah32236 жыл бұрын
How to get that yellow onsite guide. Kindly share link if possible
@cjmillsnun6 жыл бұрын
electrical-shop.theiet.org/books/guidance-notes/on-site-17th-ed-amd3.cfm. That said, I'd hang on for the 18th Edition which is due out next month. That way you'll only be buy once.
@jwflame6 жыл бұрын
Available from Amazon here: amzn.to/2Je3CxY
@wasimullah32236 жыл бұрын
John Ward many thanks
@wasimullah32236 жыл бұрын
cjmillsnun perfect! Thank you
@MrPaul1f6 жыл бұрын
John Ward, thanks John
@Ibrahim-vt2tz2 ай бұрын
It is years I am studying and now is starting to sink in Understanding and following him 95