End to end testing on cpcs ring circuit.

[Deleted member 26818]

Each accessory on the ring should have a similar reading.
You should not be able to take the measurement at spurs, as there should be only one CPC conductor.

 

[1shortcircuit]

You should not be able to take the measurement at spurs, as there should be only one CPC conductor.

Very good point:thumbsup

 

[schoe]

I'm worrying now, I'm not sure whether my results are due to faulty wiring or parallel paths . As I said before all the readings were acceptable before the app licences got connected.

Even with the appliences connected I'm still getting the same end to end results when I test in the consumer unit

 

[schoe]

Very good point:thumbsup

I was never taking the measurements from a spur just a double socket even though the ring did have fuse spurs in it.

 

[1shortcircuit]

As I said before my end to end results which were carried out in the consumer unit were,

Live to live 0.93

Neutral to neutral 0.90

And earth to earth 1.46

Which all seem to be acceptable.

It's only when I broke into the sockets in the ring did I get a different result on the earths

Okay, so you've obtained your end to end results. What is it you are testing between at the sockets? are you still doing end to end or have you moved onto the next stage and using your figure of 8 (interconnected) LN LE NE. I'm afraid I'm missing something due to lack of information?

If you are still doing end to end on the cpc at each socket (not sure why) then what have you done with the cpc's that you did end to end on in the cu? Have you connected them in a connector block to complete the ring and enable you to test end to end at the socket outlets or have you terminated them back into the earth bar?

My results were taken before the aga, and dishwasher were plugged in via a switched fuse spur. That's why I thought everything was ok till I tested them the other day.

If I unplug everything and turn the switched fuses off will this prevent parallel paths?

If there are FCU supplying a socket that these items are plugged into then just switch the FCU into the open position. This will eliminate the appliances.

I was never taking the measurements from a spur just a double socket even though the ring did have fuse spurs in it.

Please tell us step by step exactly what you have done, it is only by doing this that someone can say "Ah ha, got it! that is what you are doing but you need to do this" or " sorry mate, you're Donald Duck'ed" lol

I'm reading this thread that you have done end to end on cpc's, put them back into the earth bar and then gone around testing for end to end continuity on the cpc at each socket outlet. If this is the case then I believe this is where you have made an error.

A step by step WILL help us HELP you.

Out of interest, what tester are you using?

:thumbsup

 

[schoe]

Okay, so you've obtained your end to end results. What is it you are testing between at the sockets? are you still doing end to end or have you moved onto the next stage and using your figure of 8 (interconnected) LN LE NE. I'm afraid I'm missing something due to lack of information?

If you are still doing end to end on the cpc at each socket (not sure why) then what have you done with the cpc's that you did end to end on in the cu? Have you connected them in a connector block to complete the ring and enable you to test end to end at the socket outlets or have you terminated them back into the earth bar?





If there are FCU supplying a socket that these items are plugged into then just switch the FCU into the open position. This will eliminate the appliances.



Please tell us step by step exactly what you have done, it is only by doing this that someone can say "Ah ha, got it! that is what you are doing but you need to do this" or " sorry mate, you're Donald Duck'ed" lol

I'm reading this thread that you have done end to end on cpc's, put them back into the earth bar and then gone around testing for end to end continuity on the cpc at each socket outlet. If this is the case then I believe this is where you have made an error.

A step by step WILL help us HELP you.

Out of interest, what tester are you using?

:thumbsup

Thanks for the reply sorry if im not making myself very clear, im confusing myself and everybody else. ive used this website loads and valve everyone opinions. ok ill try again.

Ive obtained my end to end results from carrying out the tests in the consumer unit. I was just changing a socket on the same ring the other day and thought while the wires were loose ill do an end to end with the loose wires, everything else was still connected.

i was doing the end to end test at the socket just out of curiosity, the all the other cpcs including those in the consumer unit were connected in the existing sockets which then went back to the main earth terminal.

when i orginally carried out the end to end test before the dishwasher and aga were connected i was getting the above test results when carrying out the end to end tests in the consumer unit. im still getting the same results now with the aga and dishwasher connected when i do the end to end results at the consumer unit.

my only concern was when i did the end to end test just out of curiosity behind the socket my cpc results were not the same as what i was getting when i carried out the test in the consumer unit.

that is what i didnt understand, and the results were getting higher the closer i tested to the consumer.

i wasnt sure weather this could have been due to parrallel paths because when i did the end to end test behind the sockets the swtiched fuse spur was turned on which was supplying the aga, and the aga is connectedby gas which is main bonded.

your last point makes me think what i have been doing is clearly wrong.

i have done the end to end on the cpcs at the consumer unit, i have then put them back in the earth bar and tested the end to end for continuity at each socket outlet.

the tester im using is a fluke 1653

all my results on this ring circuit are,

l-l 0.90
n-n 0.92
r2-r2 1.49

r1+r2 0.67

insulation resistance all 500 meg

ze- 0.86 ohms

thanks again i hope this is a better explination.

 

[schoe]

by reconnecting the earths back into the main earth terminal, then testing end to end at each socket it would effectively be testing all the earths connected in the main earth terminal togehter.

 

[schoe]

does that sound right!

 

[Deleted member 26818]

The problem is: that the measurements should all be very similar, irrespective of where the measurements are taken.
Parallel paths, would produce a lower reading.
What you describe, suggests an interconnection or a connection to a parallel path somewhere near the end of the ring where the reading is lowest.
Which is why the reading increases the further away you measure.

 

[schoe]

The problem is: that the measurements should all be very similar, irrespective of where the measurements are taken.
Parallel paths, would produce a lower reading.
What you describe, suggests an interconnection or a connection to a parallel path somewhere near the end of the ring where the reading is lowest.
Which is why the reading increases the further away you measure.

how would you go about finding this, and what should you look for if it is an interconnetion or parallel path? thanks spinlondon.

 

[Deleted member 26818]

If you disconnect the RFC CPCs at the CU, you should not get any continuity between them and any other CPC or bonding conductor.
If you do get continuity, this would indicate a parallel path.

 

[rich.250]

When you say you are testing end to end on the rfc cpcs you are testing at the outlet on the seperate cpcs disconnected?? Not to the CU with an r2 lead??
Although it is un necessary to test your end to ends at the outlets.
When you done your R1 +R2 crossed over and R1+Rn crossed were they the same from the outlets??

 

[schoe]

If you disconnect the RFC CPCs at the CU, you should not get any continuity between them and any other CPC or bonding conductor.
If you do get continuity, this would indicate a parallel path.

sorry spinlondon for sounding stupid but how do you do this? when you disconnect them from the CU do you leave then loose or test between each end?

 

[schoe]

When you say you are testing end to end on the rfc cpcs you are testing at the outlet on the seperate cpcs disconnected?? Not to the CU with an r2 lead??
Although it is un necessary to test your end to ends at the outlets.
When you done your R1 +R2 crossed over and R1+Rn crossed were they the same from the outlets??

yeah cpcs are connected in the CU and they are disconnected behind the socket. r1+r2 = 0.67 r1+rn +0.52

 

[rich.250]

There does sound like a parralel path as spinlondon rightly said.
All the r1+r2 readings are equal within 0.05 at every outlet?