Couple Of Testing Questions...

[SSE]

1) When about to do an insulation resistance test between neutral and earth on a board full of rcbo's, should I have anything dis-connected and should I just test between the two bars or the rcbo outgoing and earth bar? Been getting funny readings but think it's just something I am doing wrong!

2)What would cause a circuit to trip the rcd whilst doing my Zs test on it?

Still trying to get a feel for testing as I haven't done much so any advice would be appreciated!

 

[tonys]

Not being funny mate, but your be better working with a tester, hard to explain things over the internet, hands on is the best way to learn imo

 

[tuckermot]

Hi gallagher

are you probing neutral and earth bar and testing whole installation in one go ??

 

[ringer]

1) ...
2)What would cause a circuit to trip the rcd whilst doing my Zs test on it?
...

Have a good think about what an RCD does. What makes it trip?
Now have a think about what happens during a Zs test. What is the tester doing when you tell it to do the test?

 

[Sparky Ninja]

1) When about to do an insulation resistance test between neutral and earth on a board full of rcbo's, should I have anything dis-connected and should I just test between the two bars or the rcbo outgoing and earth bar? Been getting funny readings but think it's just something I am doing wrong!

Have you disconnected the functional earths to start with?

2)What would cause a circuit to trip the rcd whilst doing my Zs test on it?

Observe your tester to see what amount of current it applies to the circuit under test.

 

[cselectrical65]

RCBO's should be completely disconnected before carrying out insulation resistance test.

 

[SSE]

Hi guys, thanks for the replies. Messed about with tester and tried different things and disconnected rcbo's and this solved my problem! Looks like it's just going to have to be a case off gainin as much hands on experience testing as possible to improve! Also Ringer I see what you are getting at but surely it should not trip when it's I am on the no trip setting using the 3 leads?

 

[malcolmsanford]

It shouldn't no .............so have you got a a full RCBO board or a mixture of RCBO/MCB/RCD as you say that the RCd was tripping.

 

[SSE]

Sorry I should have explained a bit better, the neutral earth problem was on a board with all rcbo's and the Zs problem was on an rcd board.

 

[Geoff76]

Hello there, just 2 questions, 1. on my reci test record sheet it has a section REC. PROT. COND.(MAX)_____OHMS. Im confused on what value should be applied here.. also what test is done is it insulation resistance,

Also on single phase domestic board measuring insulation res (meg ohms) is it done between phase and n

 

[i=p/u]

all conductors i was taught, but i did i listen , i say i did what

 

[malcolmsanford]

If that was an ECI sheet then I have to be honest and say I haven't seen one with REC (record?) PROT. (?) COND. (?) MAX______OHMS
But an educated guess would be the maximum value of Zs as in the regulations tables 41 etc.

Insulation Resistance should be done between LINE/NEUTRAL LINE/EARTH and NEUTRAL/EARTH on domestic single phase and all other installations.

For 3 phase thae same and then LINE/LINE as well.

There are exceptions to the above highlighted in Regulation 612.3.2