EICR today

[Rob_the_rich]

so you are effectively saying a fault could be effectively  by passing the cpc by using the neutral instead. I see your point.

yes, effectively

 

[binky]

would certainly explian some oddities I have come across over the years. Mind you I worked out years ago odd numbers is usually a neutral fault of some sort, just never really thought about why.

 

[Evans Electric]

It is, or should be, a ring circuit, so if you plug the tester anywhere in the ring, some of the cpc current will be going down the neutral, as above, wherever the fault is in the ring. At x1 rated current of rcd, instead of 30mA going down the cpc, some will divert to the neutral, so the rcd sees maybe 15mA, enough not to trip.

Depending on the load the same thing happens, where high protective conductor currents occur, the rcd might not see any imbalance.

I was thinking all the time , this a N to E fault    ( Honestly  )   but were unable to do any tracing .

This is a combination of a loose connection on the neutral and a squashed core in a back box, don't ask me to explain it but I have come across it before, had to pull every front and checked terminals one loose, tested fault had disappeared. 

This is what I was thinking but we couldn't get on with it . 

 

[Evans Electric]

What were the IR tests?

If the customer won't allow you to investigate a fault, then you can only note the fault on the EICR and code it.

I always prefer to try and find faults and would prefer to fix a simple fault and give it a satisfactory than have to code it and quote for remedial work, but if the customer does not want you to do that, then you can't force them.

Was the occupier, the "customer" or is she the tenant?
 

Dave , we  meggered the outgoing legs when we had some sockets off , that was OK ,   but needed to pull the plug on the fridge.    Meanwhile the old dear was mythering about the plugs being off the wall and will they be level when you put them back. 

I think as many of the guys have said , theres a N fault somewhere. 

She thought the PIR would take 1/2 hour. 

 

[Murdoch]

She thought the PIR would take 1/2 hour. 

What made her think that?

 

[Doc Hudson]

We had the kitchen ring with high trip time for the RCBO   the rest of the place was fine .

Trip time was 300mS , plus the tester dithered slightly , the two LED lights flicker, go dim then it trips. 

Tried a second RCD tester  ( Yes we are two tester firm)  That flashed up reading of 7 which immediately  faded , followed by "ERROR  5 " :C

Thinking its a faulty RCBO I swap with the next breaker but the same occurs, so wiring fault .

Readings were R1  = .22 /   Rn = .38 /  R2 = .43 /  R1 + R2 = .69                   Zs .3  

We started checking  ( not being paid for that)  but there was a socket behind a built in fridge ,  for the fridge,   old dear wouldn't let us remove the fridge ....." I should get the kitchen fitters back  they will know how to remove it  ."    ( Two screws)      Then didn't really want us to return to sort it so what do you do? 

There,s  something wrong somewhere but we've had to leave it .

The other trip times were :-

12

12

9

12

12

8

300

7.8

   :C     

Although it is not a value I would be happy with without further investigation, strictly speaking an RCBO to BS61008 or 61009 at 1x trip current, the operating time is defined as less than 300ms. So even with your dodgy circuit the RCBO is just about meeting its tolerance.  (ref 11.3 OSG).  But as also pointed out there is most likely a lose joint somewhere, based on those values (assuming 2.5mm)  r1 is about 30m, r2 is about 35m if 1.5mm (or 24m if 1.0mm),  but rn is about 50m.  I like to see readings suggesting within approx. 5m of each other, allow for a poor connection of meter probe etc..  All you can do is note it down as requiring further investigation.

Doc H. 

 

[Evans Electric]

She's an 80 yr old Greek woman Murdo .   I don't know why she imagined that , like many people , has no idea about how long things take .

 

[Risteard]

What made her think that?

It seems to be a common belief in fairness. When you explain you will need a few hours some people seem dumbfounded by this! Probably why they expect it to cost about £50!

Readings were R1  = .22 /   Rn = .38 /  R2 = .43 /  R1 + R2 = .69                   Zs .3

Have you just added r1 to r2 to give you the (R1+R2), or is this a spur? Because otherwise it should be around about 0.16 Ohms.

 

[kerching]

She's an 80 yr old Greek woman Murdo .   I don't know why she imagined that , like many people , has no idea about how long things take .

If she is Greek,shouldn't she be getting a German in to fix it for free?

 

[Evans Electric]

It seems to be a common belief in fairness. When you explain you will need a few hours some people seem dumbfounded by this! Probably why they expect it to cost about £50!

Have you just added r1 to r2 to give you the (R1+R2), or is this a spur? Because otherwise it should be around about 0.16 Ohms.

You're right there , I jotted the readings on a bit of paper ..... r1 + r2    is .69          R1 & R2     on my cert  copy was .17

 

[andymcl]

Ive lost count of people who think a pir will take 30 minutes, I show them the 10 page report and tell them that this will take 3-4 hours