Replacing old junction boxes with Wagos

[Tim Brennan]

Hi, Just recently qualified.
I've replaced some old 32amp junction boxes under the floor in my landing with Wago and Wago boxes to make them maintenance free prior to putting down new flooring.
Prior to doing this, i tested the ring continuity, r1 was 0.52 ohms, rn was 0.53 and r2 was 0.73, so was well within the 1.67 reg, now when i tested the ring once the work was complete the readings are: r1 0.47, rn 0.48 and r2 0.99 ohms. I have double checked all connections, but the r2 reading still seems a little high and doesn't meet the 1.67 guideline. I/R tests are fine. Maximum Zs is 0.54 ohms but that is on a dropdown spur to the lounge from the ring upstairs.
The reason i changed them was that there was no earth sleeving present and the terminals where not tight and could not be tightened.
I know the Wagos will introduce more resistance but just wanted to check what you guys thought.
Timmo.

 

[westward10]

Can you still get to your new connections to split the cpcs there and check continuity at that point.

 

[Octopus]

How old is the property? The twin and earth could be 2.5 mm and 1.0 mm earth...

I would use a Hager j803

 

[Jay Sparks]

Hi, Just recently qualified.
I've replaced some old 32amp junction boxes under the floor in my landing with Wago and Wago boxes to make them maintenance free prior to putting down new flooring.
Prior to doing this, i tested the ring continuity, r1 was 0.52 ohms, rn was 0.53 and r2 was 0.73, so was well within the 1.67 reg, now when i tested the ring once the work was complete the readings are: r1 0.47, rn 0.48 and r2 0.99 ohms. I have double checked all connections, but the r2 reading still seems a little high and doesn't meet the 1.67 guideline. I/R tests are fine. Maximum Zs is 0.54 ohms but that is on a dropdown spur to the lounge from the ring upstairs.
The reason i changed them was that there was no earth sleeving present and the terminals where not tight and could not be tightened.
I know the Wagos will introduce more resistance but just wanted to check what you guys thought.
Timmo.

The 1.67 is to give you a rough idea of what your r2 is likely to be if using 2.5/1.5mm2 cable. As long as your Zs is OK, don't worry.

Jay

 

[Tim Brennan]

Yeah that's what NAPIT Tech said. I'm putting the flooring in now, Thanks for the replies.

 

[Octopus]

^^ what did Napit say?

 

[Tim Brennan]

oh sorry, what Jay said:
The 1.67 is to give you a rough idea of what your r2 is likely to be if using 2.5/1.5mm2 cable. As long as your Zs is OK, don't worry.

Jay

 

[HandySparks]

[QUOTE="...
I know the Wagos will introduce more resistance ...[/QUOTE]
You shouldn't have any measurable resistance across a Wago.

 

[westward10]

His R2 has increased by 0.26 since he reconnected why is this something not to worry about.

 

[Tim Brennan]

maybe where the old junction boxes had the cpc twisted together prior to being in the terminal made for a better connection than the wagos, there where 4 junction boxes replaced.

 

[gazdkw82]

THeres a video on YouTube testing wago connectors for resistance and you'll be surprised at how little the resistance will change. Your meter may not even pick it up.

 

[westward10]

No the Wagos would not have caused this, me I would want to find it unless your original reading was incorrect because the R1 has gone down.

 

[Tim Brennan]

surely if the terminals were not tight on the line and neutral in the old junction boxes then the wagos would be a better contact and therefore the r1 + rn goes down by 0.05 ohm. As I said I have double checked all connections, i did replace about 2m of old cable with new, but im sure that wouldnt cause it.

Thanks again for the replies.

 

[tomspark93]

As said above, I wouldn't worry about it too much if the r1 and rn readings are the same and the r2 is a bit higher than expected especially if the Zs reading is well within it's limit for the protective device.

When the battery in my Fluke mft are low the leads don't always "zero" which increases readings. Als,o a good squeeze on the croc clips when testing can bring the reading down by 0.05 ohms. Other factors such as ambient temp etc may effect your test readings.

 

[7029 dave]

My jb's are maintenance free ( Dave tight), you know the old saying , if it aint broke don't fix it.