problems with test results

[chris butterfield]

Hello,

Im confused as to why I'm getting a high zs value at the socket but all r1 rn r2

ze is 0.5 but zs is .98

The other problem is a had a rcd won't trip but for some reason when something is plugged in it trips the other rcd.

All circuits bell out and test fine so could it be the rcd that is playing games with me ?

 

[davesparks]

RCDs don't play games, they react to a current imbalance. The symptoms you have described are of a reasonably common fault and a bit of logical thought and application of your knowledge of the fiends of electricity should make it clear.
You almost certainly have a N-E earth fault.

I don't see what the problem with your Zs reading is??

 

[Leesparkykent]

What was your r1, r2 and (R1+R2) results for the circuit?

 

[chris butterfield]

Yeah thought it was N EARTH FAULT but what has confused me is all the circuits are in the correct side of the rcd ways but the other rcd tripped !!!!!!

 

[chris butterfield]

Am i correct in saying that if i had a n earth fault then the rcd won't trip anyway ?

 

[Ian1981]

Is this a new install?
You may have neutrals crossed somewhere on one rcd but the live from the other rcd assuming it's a dual rcd consumer unit?

 

[Leesparkykent]

You have a neutral-earth fault on a circuit that's covered by the RCD that's tripping.

 

[Pete999]

Hello,

Im confused as to why I'm getting a high zs value at the socket but all r1 rn r2

ze is 0.5 but zs is .98

The other problem is a had a rcd won't trip but for some reason when something is plugged in it trips the other rcd.

All circuits bell out and test fine so could it be the rcd that is playing games with me ?

What was the R1+R2 reading?

 

[chris butterfield]

Yes its a new install.

The circuit that trips is tripping the other rcd. Could be i have a N crossed ?

Looks like ill re test in the morning

Basically then i have a N/E FAULT ?

 

[chris butterfield]

But why is the other red not tripping on test ?

Is this down to the N/E FAULT ?

 

[Ian1981]

Yes its a new install.

The circuit that trips is tripping the other rcd. Could be i have a N crossed ?

Looks like ill re test in the morning

Basically then i have a N/E FAULT ?

If a circuit on one side of the rcd trips the other rcd then yes you've crossed a neutral by the sounds of it

 

[chris butterfield]

MMM (n) crossed then.
Also poss n earth fault on the other red for it to not work on test ?

 

[chris butterfield]

Also think i may need my dialog meter cal as it keeps giving me different zs readings on the same circuit. Not too keen on this dialog 9083p

 

[Octopus]

All circuits bell out and test fine so could it be the rcd that is playing games with me ?

can you spell out what you mean by "bell out" and test Ok

How many circuits do you have on each RCD?

 

[Loki]

You said that the Ze is 0.5
Im guessing its a tns & not tncs then as its over the 0.35 Ze max



If using 2.5 (1.5) T&E

Zs 0.98 - Ze 0.5 = 0.48

4 ÷ (2.5 + 1.5) x 0.48 = 0.3

r2 = 0.3 ohms
r1 = 0.18

Roughly lol, Am i close?

 

[Leesparkykent]

Had this two weeks ago in a fire damaged bungalow. I know it sounds implausible to some but a neutral to earth fault on a circuit stopped the RCD from tripping and test button wouldn't work. Dissed circuit in question...RCD now tests fine and test button works.

 

[Strima]

You will more than likely get a higher Zs through an RCD due to it's own resistance and also the test meter puts out a lower current on the no trip setting so the result isn't as accurate.

 

[chris butterfield]

pretty much lol

I think also my meter is playing uo as I'm getting different zs readings from the same bloody socket aghhhhhhhh need a vino

 

[chris butterfield]

pretty much lol

I think also my meter is playing uo as I'm getting different zs readings from the same bloody socket aghhhhhhhh need a vino

 

[davesparks]

Yeah thought it was N EARTH FAULT but what has confused me is all the circuits are in the correct side of the rcd ways but the other rcd tripped !!!!!!

Draw it out and work out where the current will flow,