Thank you again mr Ward. Really appreciate all your videos

I really love your videos John !! You have taught me so much, the way you lay it out and explain everything properly really fills me with confidence for my next job. I've been a sparky since I left school. I'm 42 now. I wish I had you as a lecturer at college when I was sixteen. It would of sunk in so much quicker. You're a legend mate, keep it up!!

Thanks so much for the detail you go into in these videos. You’ve bin a lot of help with my defined scope course. Legend. 👍🏼

Hi JW, id just like to say thank you for these electrical videos, I'm just coming up to the end of my apprenticeship and preparing for my testing and trade test and your videos have been more of a help thank anything else, including lecturers. So thank you, my understanding from testing to earthing systems. Keep up the good work it doesn't go unnoticed!

Brings back memories of my working life! Good vid, thanks!

Wonderful video, best on the Internet for sure. Keep it up John, keep them comming.

Good one jw...I've watched your videos repeatedly. Thanks

Really like these presentations this presenter is excellent!!

Excellent description very easy to follow.

Great video John , really helpful your videos as I'm trying to pass 2394/95 exams👍

Another great video, thanks John

Well explained this explanation and video stays in my head

John; Thanks for the information.

Hello john love watching your videos always informative. Could you explain sometime about how the PFC and earth loop impedance effect how quickly a circuit breaker or fuse will trip and what is allowable. Best regards Chris

In the US most regions I have worked in have the TT / ground rod install. The maximum allowed impedance is 25Ω on a single ground rod. If it is greater than 25Ω than a 2nd ground rod at least 10' (3 meters) away is required.

Thanks John!

Great video mate.

Superb john.brilliant.

My jaw dropped when I saw the impedence on a TT compared to a TNS and TNC-S

Thankyou kindly helped loads.

thanks for the info

Hi John, great video! What about IT systems, how could we measure some kind of loop? We would actually want to measure earth rod resistance without having access to the actual rod. I've seen in some occasions that the earth rod has been covered by a concrete slab once the building was modified and there isn't any physical contact to the rod but from the main earth bar at the main electrical board. However on IT systems (three phase) the loop path from L-E on a good installation should be very big (as the insulation resistance of the cables?). What are your thoughts on this situation? Thanks!

Hi jw great video again. I am about to embark on an electrician course to become part p registered. I hope u don't mind fielding questions as I find your videos a great source of information

Hi John DO you have any videos fro a refresher on 3 phase PFC and E Loop testing..Many thanks for all your hard work..regards

Hi john I've been told that if we now run power to a shed , garage etc then the dno will not allow the house earth to be used in the shed, so we now have to make the shed a TT system, is this correct and would a Ze test suffice or do we need to carry out the earth electrode test with the correct tester and test the ground around it etc?

Prospective fault current determines the class of breaker you van install. PFc of 5kA you cannot use a regular cheap domestic breaker, but must use one rated for 5kA breaking, otherwise a fault can destroy the breaker without it actually opening safely. Mostly in domestic you never see this, unless you live right next to the substation, have brand new cabling that comes direct from there and there is around 20m of cable total between you and the transformer. Then you need much higher rated breakers. Of course on the supply side the supplier always puts a much higher rated breaker, as there a shorted cable will have very high fault current, and upstream on that cable at the main line connector there will be a fuse link as well, capable of massive fault clearance. Fuse is single use, but in general it is always rated to protect the cable to the house, not the house, so is generally 100A or so, while the breaker downstream to protect the house is 63 or 80A instead. If the fuse blows and the cable is fine they will always replace the house breaker as well with it, as it then is likely to have been faulty, if it did not clear a fault before the fuse did.

just wondering did you test the earth with the live wire coming from the main meter. to test the earth loop impedance ?

👏👏👏👏 thanks JW

Thanks very helpful

Top Man John!

Hi jw can you explain how is installed rcd thanks

Can you also explain how to test for system loop impedance Zs. Thanks a lot

I've got one of the TN-S / TN-C-S hybrids where there is both a braided earth strap on the incoming metal outer and also a 10mm earth going into the Cutout via a block marked PME. My ECI is recorded as 0.27ohms. Would this indicate that it is indeed a TN-C-S or could it still be a TN-S. I've had no reply from Western Power about what they have it recorded as. The Electrician who installed the CU ticked both the TN-S and TN-C-S boxes. His recording for the PFC was recorded as 0.85kA. Nominal voltage of 245v.

Hi John can you please do a video on loop and psc testing using the kewtech kt62 or the ROBIN kts 1620 MFT'S Many thanks. Your videos are great and a big help keep them coming

Thank you

In principle, is the loop impedance tester just an ampmeter, voltmeter and known load, applying ohms law and negating said load?

John you are better than my tutor, but I am not going to tell him that

Your the best

JW, One thing I don't understand about America, they don't test their installations before livening, like the rest of the world. I was speaking with an "electrician" from the US, and he asked me why he should even do these tests. Weird.

John, how is then gonna trip the fuse with 6KA breaking capacity if the PFC is well below 6KA during a direct fault between Line and Earth or Line and Neutral? I know breaking capacity is different from Tripping capacity but what happens during a direct fault, how is it gonna clear the fault?

Hi John, on the generic schedule of test results, what is Zs at DB referring to? is it a test like for Ze but with the earthing conductor in place?

Thx

Thanks JW Great Videos fantastic help with my collage homework MORE PLEASE JODY

Hi john, I'm sorry if this is very basic but does the loop impedance vary from time to time for a specific circuit? or should it be pretty stable? the reason I ask is because installed a spur double socket from the ring final in my house and the reading at the spur was originally 0.65 ohms, then all of a sudden it went as high 0.95 ohms, i checked it again today and it was back down 0.68 ohms. Is this normal or could it something more sinister? thanks

thank you for the video , what is the loop impedance test device name ?

do you have a video on the following I bought a ceiling light but the live and neutral wires are not coloured. how can I identify??

Does your Sharpie seep through to the paper on the other side?

I assume "Loop Impedance Tester" sources current from active wire and voltage is measured at ground pin, but where is the reference. Is there a third ground wire that system uses as a reference ground?

Can you explain reg 434.5.1 ? Thanks

Is a loop impedance test one of tests on a new installation? There is continuity, polarity and insulation resistance. Is this one?

Hold a minute. Most of testing devices requires connection between L+N+E to determine Ze and Zs. How I can understand that?

for anybody studying 2365 the values for TT is anything in between 21 ohms and 200. however is reality 100ohms is max . what I've learned anyway

how to connetion wiring by hager mz915?

what would be the next step if a circuit didn't meet max zs for example tns or tncs

Why disconnect then later connect? Suppose I connect directly to the earth bar and incoming supply?

I really appreciate this videos, not this one but, some of them. Thanks for sharing these info. Dear John, I am from Brazil and I am looking for a equipment that can measure a line impedance. Can you indicate something to me?Thank you!Alexandre

Testing like this is important. I wish the electrician that installed my bathroom light/heat/exhaust fan did some testing besides just turning it on to see if it works. Some months later, I was testing with my multi meter the continuity between earth and neutral from my fluoro light in my garage and found that there was no continuity! I went hunting for the problem and found this - drive.google.com/open?id=0B5Wm-dWZjGIpdXhhM1JUV3VmSGc (Sorry I've shown this pic before). Also notice the red wire connected to the top terminal on the fan? That is actually a neutral connection, I'm not sure what the regulations are for re-purposing the wire that is normally used for active connection without using a sleeve or heat shrink to indicate it being used for neutral connection. Anyway, I cleaned up the mess of wires and added a junction box, so it looks like this now - drive.google.com/open?id=0B5Wm-dWZjGIpQTBtYkZHRHNNdGM

hi its not clear whether you are testing it to the L or N they are not marked on your diagram or mentioned.

You could have been a great airline pilot

someone send me the photo of a loop impedence machine that tests loop

Interesting video. The audio looks slightly out of synch to me

I hope sharpie send you free pens

Why is this not a dead test

Talking quickly and monotone!!!!!!!!!!!!!!!!!!!!!!!!!!!!!