High R1 & R2 reading

[Simon Hall]

Hi I was wondering if any one can help me. I've done a R1 and R2 reading on a lighting circuit and there is a high reading in the middle of the circuit. I would usually expect the highest reading at the end of line. Does any one know why this is happening thanks

 

[derek]

Have you checked all terminations are sound?

 

[Simon Hall]

Yeah all tight, it's part of a consumer unit change and done in 1mm but after the high reading there is a 1.5mm to the next light fitting as there was a fault before would this have an impact

 

[derek]

Just because they are tight doesn't mean there is a good connection, there could be insulation in the way or a damaged conductor. If nothing is visible then you need to get your tester out and break the circuit down until you find out where the problem arises.

 

[telectrix]

do a R2 with a wander lead. that will tell you if it's on the Lor the cpc. narrows it down.

 

[Amp David]

Check between the loop and cpc as well as the switch and cpc if at a rose.

 

[telectrix]

how much higher? if the light with the higfh reading is 2 way or 3 way switching, you'll be reading the strappers as well.

 

[Deleted member 72666]

How do you know for sure the 'middle' of the circuit isn't the furthest point?

 

[Simon Hall]

It's not much higher about 0.30ohms higher it's just on a 1 way light it has thrown me tho as it then drops down again. I know it's in the middle as I've worked out the path of cable as I had to find a fault

 

[Silly Sausage]

How/Where are you taking your measurements?
It could be a poor probe/terminal contact giving a high reading for example.

 

[Simon Hall]

I was reading between switch live and earth so then I can operate the switch to check polarity

 

[Farmelectrics]

What made you test in the middle of the circuit and not end of line

 

[Simon Hall]

I've tested at every point to check there's an earth at each point, but the light point in middle was the highest then dropped down again

 

[telectrix]

as i said before, is that light 2 way or 3 way switching?

 

[Simon Hall]

It's 1 way, 1 switch