Polarity Test

[wiganspark]

i thought interconnecting r1/rn on your ring was the only way to prove polarity on sockets before the circuit is energised ?

 

[Jurasic Spark]

Simply turn the switch on and off. You have to use some common sense when testing.

If that way is incorrect how do you test for polarity?

Agreed but how would this reveal a L and E reversal

 

[Plonker 3]

Agreed but how would this reveal a L and E reversal

When you operate the switch your meter will either show a very high reading or a very low reading.

Visually check the device is correctly wired at the terminals.

So how do YOU test for polarity if you dont know the answer to your own question?

 

[Farmelectrics]

jurasic i said earler in my post that you would have proved polarity by doing r1 r2 once we carry out are r1 r2 test and it conforms to bs7671 that means after are ir test we can energise the circut i did say that in my post

 

[markc123]

I remember watching a video showing something close...

Found it
Polarity - YouTube


I'am at college, never really done any testing and want to get a head start for when I need to learn them. I know I'm probably asking silly questions but I'm trying to learn!

Hello buddy, if you don't already have it.....go on amazon and buy Guidance Notes 3....i know you'll probably be able to loan it from your college - but its best to have your own copy. Make GN3 your bedtime reading for the next couple of months and you'll have a very nice head start on the course. GN3 is the fountain of knowledge for testing.

Good luck.

 

[chrish_1977]

Polarity is a live test

Is it?

A R1&R2 test can be used for this too.

That's what they told me on my 2391

 

[Plonker 3]

That's what they told me on my 2391

It can actually be either a live or dead test.

 

[Farmelectrics]

r1 r2 honest it proves polarity lol

 

[Jurasic Spark]

It can actually be either a live or dead test.

There are 3 objectives which need to be confirmed whilst doing a dead polarity test. Once this is done the live polarity test is to ensure the correct polarity of the incomiong supply, done with an approved voltage tester before energising the supply.

 

[NrVolts]

i think i know what durassic spark is aiming at.i had the same thoughts at college.concider this R1 and R2 is a loop .you have you meter on the ends of that loop .ok now make a break in the earth ..oh look you get open circuit ,just like you would if you operated a switch .visual check connections and a live test would be best,but even that wouldnt find two swaps in polarity in one circuit.
his point is spotting reversed polarity.hope this edit worked as ide look a right numpty if not lol.

 

[Jurasic Spark]

When you operate the switch your meter will either show a very high reading or a very low reading. Would it make any difference to your readings if you swapped the leads over on your meter???

Visually check the device is correctly wired at the terminals. You can only visually see the terminals and not whats inbetween

So how do YOU test for polarity if you dont know the answer to your own question?

Think about it, its common sense.

 

[Plonker 3]

Well then if what is says in BS 7671, the OSG and GN 3 isnt good enoigh for you I suggest you wire all circiuts in singles in trunking pulling each core in individially. That is the only way you can 100% guarantee none of the things you point out actually occur.

 

[Jurasic Spark]

Well then if what is says in BS 7671, the OSG and GN 3 isnt good enoigh for you I suggest you wire all circiuts in singles in trunking pulling each core in individially. That is the only way you can 100% guarantee none of the things you point out actually occur.

No need to get sarcastic I'm only trying to stimulate thought, after all electrics is a thinking man's game and the most technical of all the trades. None of the books you mention are instruction manuals, you might need to apply what you refer to as "common sense"

 

[Plonker 3]

No you are correct. But we are talking about fixed wire testing here not appliance testing which doesn't fall under the remit of the OPs question.

So how do you check for polarity if all the obstacles you stated are in the way?

 

[Jurasic Spark]

A bit more thought with regard to RFC testing as the O.P did refer to this....

The end to end values from Step 1 of the recognised test sequence for a rfc containing 4 skts are:
L 0.5 ohms N 0.5 ohms CPC 0.83 ohms.
When cross connected at the board the following values are read at each skt using an adapter and not removing the socket front.

State whether they are acceptable and if not give possible reasons for the bad readings


Step 2
Socket 1 = 0.25 ohms
Socket 2 = 0.25 ohms
Socket 3 = Over Range
Socket 4 = 0.31 ohms

Step 3
Socket 1 = Over Range
Socket 2 = 0.34 ohms
Socket 3 = Over Range
Socket 4 = 0.42 ohms