Types of MCB / Circuit Breaker, BCDKZ

thanks John

Thank you John

Once again,thanks

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 .

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.

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 ☺️

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 ?

Nice👍

merci 🌹🌹💚💚

What a fantastic video. Thank you so much for this John. very informative and very well broken down and explained. Great work :D

Great content your a beam of electrical light for the curious mind. An enthusiastic thumbs up 👍

Mr Jhon
At what current Btype 32 Amp and C Type 32 Amp MCB start triping.

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?

I wish I had a brain like you, very good information 😁

👍🏻👌🏻👌🏻 cheers.

Why is TNS Ze a high value up to 0.8 ohms ? Is the supply earth conductor smaller than the supply neutral ?

Why does it just give Zs values. What about R1+Rn as you mention this must be low enough also for breaker to trip

Are these Zs values the same for RCBO's . With type D is it written on the breaker if its 10ln or 20ln

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?

How Can I Get English Mediumboo?

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!

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.

Hi , Ilike your lecture.Thanks

And a Hammond L solemnly sits in the background <3

Dear John, this video is graet. Regards, from Hungary

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?

how many videos must i watch for someone to properly explain 3 fucking numbers on a MCB???

Talk alil bit slower..

helpful and informative. Great lecture JW

Simple,and precise

Actually Type A exists. I've holded some MCB-s that are Type A. Extremely rare.

it's Good understanding 😜 for bad Electrical Engineer's 🤘

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

HIoT

Very nice & Crystal clear VDO. Can you please explain why MPCB used in Industry and disadvantages / Advantages over MCCB's.

What is the temperature rating of the lugs?

What type will you recommend for Airconditioning unit

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???

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.

In my industry, the caravan industry we us type B and type C, predomantly it is type C

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.

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 .

Is the curve type of breaker is dependent on the length of cable.i

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).

Thanks Mr ward for all of your informative videos, without watching your video, I couldn't progress in my electrical installation course. Thanks again