New Voltage Tester

[Shaneyboy]

I have recently bought a new Fluke T50UK Voltage Tester. The instruction manual is basic to say the least. Can I seek advice regarding the following:

1. When carrying out work and making sure that the circuit is dead, do you only have to check between live and neutral to be safe?

2. It has the capability to check polarity. What is a polarity test, in what circumstances is it carried out and how is the tester used to do this? I may of course never need to do this test, but I hate not knowing how something works...

Thanks in advance.

 

[RF Lighting]

See post no.2 but the rest is worth reading too.

//www.diynot.com/forums/viewtopic.php?t=7553

 

[PrenticeBoyofDerry]

1. When carrying out work and making sure that the circuit is dead, do you only have to check between live and neutral to be safe?

No you also test between live-earth and earth-neutral

2. It has the capability to check polarity. What is a polarity test, in what circumstances is it carried out and how is the tester used to do this? I may of course never need to do this test, but I hate not knowing how something works...

http://www.tlc-direct.co.uk/Book/8.4.3.htm

 

[Shaneyboy]

Thanks boys, first query now fully understood.

PBOD, I read that link and found it very complicated, to be honest I didn't fully understand it, but thanks anyway. It seems as though polarity testing is not something that I am going to have to worry about doing basic household jobs.

Kind Regards.

 

[PrenticeBoyofDerry]

It seems as though polarity testing is not something that I am going to have to worry about doing basic household jobs.

If basic jobs don't include electrics, but a very important test on electrical circuits.
This may help you understand better http://www.electricalexams.co.uk/pdf/EQ Polarity.pdf

 

[333rocky333]

The polarity check they are refering to is not a test as such what i think they mean is the display shows a " - " voltage when reverse polarity.

If for example you put the tester on a battery and the display showed 6 volt then the red lead/probe is the positive terminal and the black/lead probe is the negative terminal.

If however the display showed -6 volt then you have the leads reverse polarity or the circuit is wrong

 

[PrenticeBoyofDerry]

The tester can read continuity, so can do both dead and live polarity.
http://datasheet.octopart.com/T50/UK-Fluke-datasheet-538901.pdf

 

[333rocky333]

The tester can read continuity, so can do both dead and live polarity.
http://datasheet.octopart.com/T50/UK-Fluke-datasheet-538901.pdf[/QUOTE]

Proberly can but i think the feature there plugging is

• For DC voltage, the polarity of the voltage
displayed refers to the instrument test
probe (+).

 

[Shaneyboy]

PB, that second link was much better. I am about to extend my upstairstairs lighting circuit into the loft. I have spent a while learning how to do this properly and that link now makes sense. I am still studying it and will get back to you with more questions no doubt.

Regards.

 

[PrenticeBoyofDerry]

If you want to get a better understanding of testing may, I offer you advice on a publication that would be a great help to you?
practical guide to inspecting testing and certification
This book will give you a step to step guide on all the test you are likely to come across, good description with additional pictures of the steps.
You will find that the fluke 50 will satisfy some of your needs to the dead tests but will not give the reading/measurements you will require for full schedules of tests. Will need a more specialised piece of kit for that, such as a MFT(multi-functional tester) http://isswww.co.uk/17th-Edition-Testers/ these can be hired.
The OSG will also be a useful source of knowledge to test procedures and guidance to requirements.

 

[Shaneyboy]

PB,

This test is a dead test ... the supply must not be disconnected.

A dead test is when the power is off to the CU though?

Also, the temporary link between line and CPC, is this simply an off-cut of a piece of T & E or something specially purchased?

Kind Regards

 

[imroberts]

Also, the temporary link between line and CPC, is this simply an off-cut of a piece of T & E or something specially purchased?

Some people use choc blocks to connect the wires together, some have purpose made leads with crocodile clips on each end.

Whatever's convenient to you I would say

 

[PrenticeBoyofDerry]

A dead test is done on a circuit or circuits that are not live, so the power will be isolated for the circuit being tested.
If it possible to do so, I would consider isolating the whole board, just as a safety precaution.
Also disconnect all loads on the circuit being tested.
The link can be made in a number of ways. Some connect the phase conductor to the earth busbar, when testing for r1+r2, not a method I really prefer.
But you can use any type of connection that will give you good contact.
My preferred method is using a Wago, but terminal strip, even a junction box, you can use a croc clips but sometimes the reading is not that great and jumps about a bit, if you have not got good contact. You can do this test without any extra length of cable, just connect the ends of the two conductors (phase & CPC) together.