Zdb / E loop and Psc on sub DB under ELU

[Dylboy]

Hello

Wondering how to test a sub DB which is fed from Main DB but under and ELU ?

The moment I test E loop it trips the ELU. We don't have the fancy tester that blinds the ELU so wondering how else to test it ?

I have just been told to make a note of it and that's that but once more I want to dig deeper....

So for the Eloop can I just measure the resistance of the Earth from main DB to Sub DB and then the restiance of the phase and then add together to make a" loop " and then do the Rmax = V / 2 x I to then make sure it can trip the CB that feeds it?



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[Dave A]

Bridge the top terminal to the bottom terminal for each phase and neutral of the earth leakage unit with housewire (10mm is great for a typical home installation) as a temporary bypass measure just for the purpose of the test.

[Dylboy]

Bridge the top terminal to the bottom terminal for each phase and neutral of the earth leakage unit with housewire (10mm is great for a typical home installation) as a temporary bypass measure just for the purpose of the test.

Perfect, thank you. A lot simpler than what I had in mind... Will make up some nice leads for it, some panel flex 10mm.

I see on the Internet the UK sparks are using the R2 lead thing that has a pozi bit magnet joined with a cable to a Croc clip to do the shorting... Will experiment with that idea.

Thanks Dave!

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[ians]

Once you have been hands on working with equipment for as long as I have ... you learn which tools are the best for the application.

For example I still have matabo machines from when I started the business 31 years ago ... I found for steel work metabo would be my first choice.

Brick and concrete ... Hilti would be my first choice ... even though the support for the product in SA for small business is so crap ... the machine quality is still the best.

Wood work ... festool if you can afford it ... other wise Makita makes a really good product ... all my woodworking machines are Makita

A good example of unsuitable combinations ... 15 minutes using the Hilti vacuum in the workshop connected to the drum sander and ... the Hilti machine stalls ... the makita vacuum will run until it is full.

Yet if I use the makita vacuum on site with the dustless chasers ... 3 days and the motor is %^&* ... the Hilti just keeps going.

Another example using a TE 55 for chipping walls ... bad idea ... yet you can drill 30 mm holes through concrete floors ... all day long ... I have a small makita breaker .... we use it for shipping walls ... it can run all day.

When it comes to test equipment ... fluke wins hands down ... It's is too dangerous to use other tester ... I feel confident putting my hands in a 1500 amp DB using a fluke test ... I would wear rubber gloves with leather gloves over them if I were to use any other make of tester. Yes I have made that mistake of forgetting to change the leads ... all you hear is small pop sound and the fuse blows inside the meter.

The fluke test leads dont last long but compared to other test leads ... I would rather get the fluke ones.

[ians]

If you plan to do testing in the future ... spend the money and buy a decent multifunction tester ... like mA current clamp ... once you have one ... it makes testing a breeze ... fault finding becomes a pleasure rather than a mission.

Things like loop impendence tests at the socket outlet ... especially if you cant switch off the power ... suddenly a breeze and you can verify the wiring and etc is correct.

I had to do testing at a school today ... I couldn't switch off the power .. .got all the test results I needed and gone without them even knowing I was there ... no need for a pieces of paper and a pen to record shyte.

Test ... save ... next ... back to my cool office ... download and sent.

Another advantage is the test results can be saved for future reference ...

I believe it should be law that every inspector has a multifunction tester with a GPS to identify the location and the test result ... it would reduce the amount of dodgy COC's.

In fact an owner of a property or person renting a property ... being the "responsible person" ... I would insist that the test results are recorded ... photos attached with the location and time stamp.

[Pieter00]

What’s the make and model of this tester?

[Dylboy]

Ians i a 100% agree with you ! I want an MFT with the no trip especially for the reason of sage live testing.

Liek your job of the school that is perfect, we often did commercial buildings and no matter how much planning goes on someone is effed off the power is out....

I have my eyes in a couple from the UK... just need to finalise some things here and then save for that.

Even the Miliamp meter... I have a few i want but for starters have a cheaper one that has good reviews in my basket ready to order...
Can not wait for either.


If you need a 10mm hole but only a 1mm drill bit you in for a long time.... but a 10mm drill bit it is quick... the right tool for the job....

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[ians]

When I was bass fishing ... a gloomis fishing rod and Callais DC reels was expensive ... I believe you need the right tools for the job ... my goal was to win the season in our province ... I got a credit card and used it specifically for the tackle I needed ... and paid it off over a period of time ... then closed the credit card and cut it up ... I found a partner who was just as dedicated to winning ... we achieved our goal and won the season with a bag average of over 8 kg for the season ... I caught more than 50 x 2kg bass and more 30 x 3 kg bass in one season.

So if you are serious about your job and want to be the best at it what you do ... make sure you have the right equipment to achieve your goal ... get rid of that expensive phone and contract get cheap transport and focus on what pays the bills.

Dont make mistakes like I have and go over board ... by buying fluke 435 and top of the range thermal imagers ... unless of course that is what you are going to focus on.

I may drive an old scrap vehicle ... but when it comes to my work ... I have equipment in my business is worth more than my house ... at the end of the day it shows in the quality of my workmanship and attention to detail which results in return customers and no need to advertise ... every single job I do is from word of mouth.

If I need to chase a wall without dust I have the right equipment ... if I need to work 14 ft in the air ... I have the ladders and scaffolding to do the job .. .you get the idea.

[Dylboy]

I agree so much with all you said there, I am slowly building up the arsenal, I mostly now only get the specialist tool when required for a job as been cought out before preempting a purchase for a job that then falls through and cashflow a bit shot then, but when you use that tool once and makes what would have been a 30 min job a 5 min one it is so so worth it and if not double worth it haha.



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[ians]

There are a couple of different brands ... my personal choice is fluke ... the guys at comtest have grown over the years and the guys working there have have many years of experience ... so the support is good ... but more important the quality and safety is the best in my experience. Some of my testers are obsolete and still work 100%

Megger is punting their multi function tester ... but I dont have any experience with the product.

Major tech have a multi function tester ... but unless it has a K in front of the model number ... I wouldnt use it for anything more that testing batteries in my workshop.

Metrel also make a good product ... I have a power quality analyser and it is pretty robust ... they also do a multi function tester.