R1 AND R2 - CAN I FIND R1 IF I ONLY KNOW R1+R2 - WHAT ARE THE RING AND RADIAL CIRCUIT DIFFERENCES
Vložit
- čas přidán 12. 11. 2022
- In this video from LearnElectrics we will look at how we can find R1 for a circuit given minimal information; and show just what the differences in R1 and R2 are in Ring and Radial circuits.
We’ve had several requests from people that are taking electrical assessments and one of their questions asked them - How can I work out R1 if I only have R1+R2 for a circuit?
In this video we will use, as examples, a radial circuit and a ring circuit that are both the same length and both use the same size standard twin and earth cable. But because one is a radial circuit and the other is a ring circuit, some of the circuit values are different and you need to understand these; what the differences are, why they are different, and how to calculate circuit values with them.
These skills will not only help in exams and assessments, but they are also useful for certificate completion when on-site.
As always, when testing installations and circuits, follow the safe isolation procedure and work safely
To view all of our videos type in LearnElectrics all one word into the CZcams search bar.
This is video No.171 on our CZcams channel where we have videos on a wide range of electrical topics.
Thank you, Dave you're a wealth of knowledge! keep it up you're doing a wonderful public service, blessings.
You are very welcome Anthony, I appreciate the comments. Dave.
Great explanation Dave, you are a font of knowledge! Keep up the good work👍
Thanks, will do Daddy B. You'll have me blushing next but I do appreciate the comments. Lois more ion the way. Dave.
Hi Dave.. this should have been way over my head.. but your explanation was a delight.. I learn again. Thanks..
Thanks Zed, I try my best and so glad it worked for you. Dave.
Wow! This is very informative, thanks for sharing it with us Dave. It worth it and the best tutorial on the topic for me...dl
Thanks for watching, thanks for the great comments. Dave.
I always look forward for new videos to learn more. Thanks for teaching
So nice of you to say so, that's really appreciated, thank you.
Thanks again for a very well explained and detailed explanation.
My pleasure and thank you for supporting the channel, appreciated. Dave.
Very educative go on with this great work
I intend to Anthony. Thanks for your encouragement, appreciated. Dave.
Briilent as usual!
Any chance doing a video on generators!
Eg. Floating neutrals & bonded generators as we in ireland use double pole change over switches breaking both line & neutral so have to use bonded with an earth rod!
Thanks mg.
Thank you Malachy, its now on the list. Thanks for the support. Dave.
Thanks again
Always welcome
Thank you, that was really well explained. How about one on AFDD's and do they work effectively on ring circuits?
Thanks for the request David, its now on the list. Dave.
Dave has done a brilliant tutorial video on AFDD's which explains everything you could need to know about them. I just watched that yesterday. Well worth checking out if you haven't already.
@@garywynder Yes I have watched it and I agree it is really, however when I wrote my original comment he hadn't done the video.
Hello Dave, great video as always. May I ask, in a lighting circuit with no cpc, would that mean in an EICR, the measured maximum ZS cannot exist, and will be recorded as a Limitation? Many thanks
If its a class 1 light fitting it is C2. If a class 3 light fitting them C3. We have a video on this being worked on as we speak. Watch this space. Hope this helps.
@@learnelectrics4402 thank you so much for replying Dave, I really really are grateful.
hello dave. how do i calculate the r2 of a circuit if i only have the r1 reading?
When testing continuity of a ring final circuit wired with 2.5/1.5 PVC/PVC conductors using 'Method 1'. The value of R1 is 0.4Ω, what should be the approximate value of R2
Have a look at this video Chris.
czcams.com/video/Wl1--nxRnME/video.html
Passed my inspection and testing
Last week and lots of r1+r2 and rn and x1.67 stuff
Great, so pleased for you. Hopefully the videos helped in a small way. Keep learning, its a great trade to be in, I've worked all around the world on different contracts. Dave.
@@learnelectrics4402 The videos were so helpful. Thank you
Hi very informative video but i don’t understand where you are getting conductor halves values please can you explain
We need the ratio of the two cable sizes. As one of them is 1.5mm or 2.5mm we can;t use whole numbers so we make them both into halves - since 2.5 is the same as 5 halves. Keep practicing, re-watch the video and it will make sense. Once understood, you won't forget it. Dave,
Hi Could you explain where did you get 2 number I don't understand
Thank you
Its the numbers we give the conductors to use in the calculations. R1 is the line and R2 is the earth or cpc.
Little r1 and little r2 are the end to end resistances. Hope this helps.
Great video not being great at fractions don't get the CSA multiplier factor how that is worked out.
Same here. Had to go with 15 as common factor and worked it around that. Final answer when rounded off to nearest figure worked out closely the same
@@johnwasswa good job ,I worked all out finally using a scientific calculator . I could not give up lol
Its just the ratio of the two cables but we can't use whole numbers with 1.5mm, 2.5mm etc so we make both cables into halves. The more you practice it the easier it becomes. Stick with it, learning is good. Dave.
Hi,
How can we calculate our two if we have our one 0.9 ohms
Many thanks
See above reply, thanks.
How do we work out the R1+RN in radial circuit if we only know the cable size and length please 🙏 please 🙏 help
Take a look at the video on the link below. Remember that R1 and Rn will usually be the same size and the same length. It makes things easy. Just choose 2.5 and 2.5 for example.
czcams.com/video/4XtaLItVFUw/video.html
Sorry, I meant how can we calculate r2 if we already have r1 0.9 ohms.
Many thanks
Subtracting r1 from R1+R2 will give you r2. Hope this helps. Dave.
Cheers👍🏻
Thanks for the support Robert.