WHAT IS R1+R2. How to change the values, what do they mean. 

So how will you do this test on a heating switch that has a paralel earth path, It has two earth. Please explaine if possible.

Thanks Nick for the really nice comments. There is a lot to learn but try to learn a little bit every two or three days. A dripping tap will fill a bucket. Also, draw some of the diagrams and pictures you come across, drawing it makes you concentrate on what is really on the page in front of you. The more you learn the better you become and your earning potential goes up. Stick with it, it's a good trade. Dave

Fantastic feedback. Thank you so much. It has really made our day. Lots more to come. Bux

Thank you martin, appreciate the comments. Lots more to come. Its a great trade to be in and its kept me busy for over forty years. Dave.

Thank you so much. Really appreciate the positive feedback. Dave.

Our pleasure. So glad that you found it useful.

Take a look at this video as well. Thanks for watching. Dave. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-6Re2sqGVoWY.html

Glad you enjoyed it, thanks for the feedback. Dave.

Thank you Dan. Glad we can help. Lots more to come. Dave

Thank you Paul. A great compliment and truly appreciated. I just try and put the message across as I would like it explained to me. Glad it works. Dave.

That's good of you to say Martyn. These are things that your tutor should be showing you. Thanks for watching. Dave.

@@learnelectrics4402 They have/do... Just no way near as clear, concise, understandable and at such a maneagable pace.

Thank you.

Thank you for the positive comments. We do appreciate the feedback. Bux

Glad to hear that and thank you for the comments. Dave.

You are very welcome, thanks for watching and thanks for the support. Dave.

Thank you very much for your positive comment. We do appreciate the comments. Dave.

Thanks Stuart. Yes, I will continue to make these help videos. Spread the word, that helps. Dave.

I know what you mean. Trying to keep the videos to 15 mins or so and one topic for one video. Thanks for the support. Dave.

Thanks for the positive feedback, appreciated. Dave

Thanks Nicholas, that's exactly what we like to hear. Lots more to come, keep watching. Dave.

Thank you Asim, your comments are really appreciated. A Man U supporter? I was born within sight of Old Trafford. Keep watching, lots more to come. Spread the word. Dave.

@@learnelectrics4402 Thanks for your reply Dave. Old Trafford is God's country. I'm originally a Salford lad but now live in Prestwich. Thanks for the brilliant videos and yes, I'll spread the word. Take care pal.

Stay lucky Asim and thanks.

Thank you, and thanks for watching. Dave.

Thanks for the great feedback Galliger. You will find the measured Zs maximums in the On Site Guide Table B6 which is on page 131 in the blue OSG. Take a look at our video "35 is the Magic Number" on the link below and you may not need to print anything out. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-URBD4llLU6Y.html Glad you are enjoying the videos, lots more to come. Spread the word, it all helps. Dave.

Thanks. Glad you enjoyed it. lots more to come. Dave

Just spread the word, that's all the thanks I need, and keep watching. Lots more to come.

@@learnelectrics4402 Have been spreading the word and will continue to do so for years to come. Just know your work here is very valuable in many respects. And yes I'm looking forward to travelling the world a bit! Stu

Thanks Joseph, appreciated. Dave.

Glad you enjoyed it and thanks for the feedback, appreciated.

Thanks for the great feedback, it does mean a lot to us, it makes all the hard work worth it.

Thanks Andy, your feedback is appreciated. Dave

Glad you enjoyed it. Thanks. Dave.

These are the sort of comments we just love. We are so glad you enjoy them, we try our best to pass on information in bite size chunks. Keep watching and thanks. Dave

Thanks for the support, appreciated. Its like water in a central heating system. Hot water flows into the radiator and cooler water flows out. We don't lose the water, the water flowing back has given out its heat and returns to be reheated again. Thanks for watching. Dave.

Glad we could help. Spread the word, it all helps. Dave.

A good shout there. Yes, your request has been recorded and we will look at doing one, brilliant idea, thanks. Glad you enjoy the videos, lots more to follow. Dave

Thanks for the positive comment, appreciated.

Thank you, appreciated. Dave.

Thank you Asad, much appreciated comment. Dave.

Thanks for watching, appreciated. Lots more to come. Dave.

Every assessor will follow a set guidelines but interpret these slightly differently that is why the video says to ask the assessor what he wants to see when he phones to arrange a visit to you. The video does list all the things he will want on the OFFICE slide and on the JOB slide, have another quick look George. Certificates, generally want to see EICs or Electrical Installation Certificates but do get all your Minor Works together. The more you give to him to look at the more he will know you mean business. The worst thing for an assessor is to be presented with just one certificate. Good luck and relax. Dave

Yes, I've thought of that, I have the perfect analogy to use. Its on the list now.

Absolutely we can. It is already planned, lots of requests for RCDs. Watch this space and we are glad you are enjoying the weekly videos.

Thanks John, thanks for watching. Dave.

Different tests, for different reasons. We should always try to achieve the correct loop impedance figures by correct design of an installation. Thanks for watching.

Thank you Wayne, we try our best.

That is correct. If you make the MCB less sensitive to tripping B to C to D you need to increase the current to compensate for this lack of sensitivity. Next Mondays video is about MCBs and more detail about this. Thanks for watching.

@@learnelectrics4402 Thank you for teaching the relationship of resistance and current for the Zs. but for the sensitivity of the MCB I don't understand that based on the changing type B to type C, the resistance is lower and the current should be risen, right ? for the typee of the rating 32 A, does type C have higher sensitivity than type B because type C has lower resistance value ? I don't get it, please help.

Thanks for the positive comments Glenn. Up until Covid struck the country I used to teach lots of Part P, 18th Edition and Inspection and Test courses. They are good if you are starting out, especially for mature learners of which there are a lot. BUT choose your training centre very very carefully. Some centres promise a lot and leave you still wanting. I would recommend actually physically visiting at least 3 centres before parting with any money. What are the training facilities, how much practical is there on each course, what is the written syllabus, get a copy. You are looking for a centre with a high standard of teaching, an instructor who has been on the tools for many years, not just read it out of a book or doing electrics one week and plumbing the next. I also taught and assessed for one of the big scheme providers and although they might be a little more expensive they do have a high standard of teaching and are in a much better position to advise on your next step, especially on registration as an electrician. They can be worth the extra cost and extra driving distance in the long run. As far as experience goes, some chaps have offered their services free as an electricians mate one day a week until they build up experience. Others just do minor work stuff, changing lights, repairing broken sockets etc. until their skill, confidence and experience build up. You will get NICEIC and NAPIT phone numbers off the internet. Hope this helps - be careful before you part with a few thousand pounds of hard earned cash. Dave.

@@learnelectrics4402 Dave thanks so much for taking the time to give such a detailed reply. This is great advice and much appreciated. I was thinking of this course at trade skills for you www.tradeskills4u.co.uk/courses/domestic-installer-course I am interested in later on doing the EV charging point course too. That’s all I want really someone I can work with on a Friday so I can learn. My issue is I wirk 4 days a week and I need to keep that going as I have a mortgage and children. Someone else from the industry had suggested doing an nvq level 2 with a view to doing level 3 and working on contracts but I think I would struggle to fit the course in round my job. One thing that put me off years ago was I had been told I was colour blind. I have since done an online test and I have mild deutan or red green colour blindness. This doesn’t effect me seeing the colours of the wires at all there is no confusion between earth, live or neutral. Plus I have seen there are glasses you can buy to solve this. Do you see this an issue? Thanks again Dave and sorry about the 2,000 questions. Cheers Glenn

Glenn, lots of sparkies are colour blind but there are many levels. Most don't know and it never affects their work. Don't worry about it. We have a video on this that might help. Colour Blindness Testing ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-P0Cgglc391M.html As a trade you will need the 18th Edition so keep watching our 18th edition help videos. You need as much practical as you can get so if it was me I would spend Fridays with another electrician learning the skills. Or even doing things in your own home. Change a socket, change a light switch. Make the garage lights two way. Invent things to do. Make a plan that every Friday you do just one easy job in you house. Change a ceiling rose. Fit a 13A socket with a USB charger socket. Practice is the key. Good luck. Keep watching the videos, never stop learning. Dave.

@@learnelectrics4402 thanks Dave it’s funny after sending you the colour blindness question I saw your video on it it’s like you were reading my mind🤣. Brilliant advice Dave I will definitely do that. I think I am just going to go for it with the course and practice loads and get some work experience with someone and as you suggested do work on my own house. And of course I will keep watching your videos. Thanks again for taking the time to reply.👍

Good luck, I've enjoyed the last 40 plus years in the trade, and most times the roof is on when you're working. Dave.

Absolutely. Always practice using an MFT. More practice, better skills, thanks for watching.

You will need the earth in the cpc to get your Zs. Your test meter won't work without. Thanks for watching. Dave.

@@learnelectrics4402 I don't understand your reply🤔 , you say take the line out the mcb and put it in the main earth terminal , the on site guide also says leave the cpc in and put a fly lead between line and cpc but surely this leaves parallel paths?

Yes, but think about it. Most circuits have the L+N+E going the same route so they will be almost the same length. As the Neutral is the same size as the phase, and the earth usually smaller, this means that R1+Rn is less resistance than R1+R2, so the short circuit current could be higher. Hope this helps buddy. Dave We have a great video about this ... Cable Lengths and R1+R2 ... on this link ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Qq_9MNH8XxU.html

@@learnelectrics4402 Thanks, what you say makes total sense. Just we are never asked to check the R1+Rn to make sure it is less.

Stick with me buddy, we'll get you there. Dave.

little r1 can be a number on its own, and can little r2. But R1+R2 is an expression, a symbol if you like. There is no such thing as big R1 on its own in a ring circuit. Take a look at this video. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-6Re2sqGVoWY.html

Thank you for watching. Appreciated.

The supplier will just give a general figure if you phone them and often nothing like the actual for that property. It is quicker and more accurate to measure it yourself.

If the fault was neutral to earth then you would not have an overload since the resistance of the appliance is still in circuit. You may find the RCD trips though. Good question. Dave.

@@learnelectrics4402 not sure why I asked this as they're effectively the same by being connected at star point 😂

Glad you did Ed, someone else might have been wondering the same question.

Thanks for watching, appreciated. As it says in the video this is just for TNCS and TNS systems. We are making a separate video on TT systems so please keep watching. Lots more to follow. Dave.

@@learnelectrics4402 thank you I cant wait to watch a video a but TT disconnecting time.

Glad that you are enjoying the videos.

Three separate single phase readings.

Thanks for watching.

Correct Tony. But we are only looking at copper here. Thanks for the input. Dave.

Good question. RCDs are additional protection, additional to that provided by MCBs. I know what you are saying but we are just telling you what the Wiring Regulations require us to do. Lots more to come, hope you are enjoying them. Dave.

Nice one. Thanks for watching.

Option three is the table next to the see-saw where it says option 3. Have a look at 15:04 onwards. Changing the circuit breaker size. Thanks for watching.

Think of it like hot and cold water in a central heating system Mike. Hot, energised water flows into the radiator, gives off its energy as heat and then flows back to the boiler as cooler water to be re-heated, re-energised, and flow around the system again. Hope this helps. Dave.

Thank you. Much appreciated comment. Dave