Hi

[neil19]

Hi all, i have a problem

I recently installed a new 10way 17th edi board.

5 breakers either side of the RCD's. The system is a TT one.

The main switch of the board is on the l/h side. So we are working from left to right.

I have a kitchen ring main on the left hand rcd side. When i plug a kettle, microwave or w/machine + tumbler in, it occasionally takes the R/H SIDE RCD out, not the L/H Side, of which its protected by????

It doesnt happen all the time, it is very intermittent.

I have made sure, and double checked that all the neutrals are in the correct location, and not shared (i even have a loop reading for them),.

Dont suppose anyone has any ideas???

the loop reading is somewhat different as well, and is coming in at, 52.2ohms????

 

[Zeespark]

Are your RCD's installed and wired correctly?

AndyGuinness

 

[neil19]

Hi Andy,

they are

 

[Zeespark]

Have you checked the earth leakage of the appliances? just a shot in the dark/thought.

AndyGuinness

 

[Andy™]

an N-E fault on the other side may not have enough of an imbalance until a higher load is there.

whats the IR of all circuits?

 

[neil19]

thats what i was thinking, but the appliances are brand new???

---------- Post Auto-Merged at 17:23 ---------- Previous post was made at 17:20 ----------

the insulation resistance tests all came above the 200

for example the kettle was on first thing, and nothing had tripped, then all of a sudden the rcd would go, and its a bugger to get back on. (and its not just the kettle that it happens to) it also takes the main 100a/100ma rcd out?

 

[Zeespark]

Is the board Insulated or Metal Clad?

AndyGuinness

 

[Sidewinder]

Is it only the ring circuit, can you isolate everything else in the board apart from the 2 rcd's and get the "wrong" one to trip when only the ring circuit mcb is on and only the appliances in use?

BTW why not update your location to show where you are?

Welcome to the forum too!

Can you do earth leakage tests on the cpc's?

Are all the circuits electrically segregated and I mean fully?

There are definitely no shared neutrals or earths?

Have you got anything spurred off the cooker circuit, say a socket which is then looped back into the ring?

 

[neil19]

Is the board Insulated or Metal Clad?AndyGuinness

its insulated

---------- Post Auto-Merged at 17:53 ---------- Previous post was made at 17:46 ----------

hi, i shall update after this msg. And thank you.

right,

*i havent isolated that one circuit i shall try that. By doing that i presume you mean by removing everything everything else and just leaving that one circuit?

*silly/naive question but how do you do earth leakage on the cpc's?

*i believe they are all separated?

*not 100% sure if any any n's or e's are shared at this stage, still awaiting the client to pay for the additional cost, as all it was, was a board change and a periodic?

 

[Sidewinder]

its insulated---------- Post Auto-Merged at 17:53 ---------- Previous post was made at 17:46 ----------

hi, i shall update after this msg. And thank you.

right,

*i havent isolated that one circuit i shall try that. By doing that i presume you mean by removing everything everything else and just leaving that one circuit?

Try just turning the mcb off first

*silly/naive question but how do you do earth leakage on the cpc's?

Easiest & quickest is an earth leakage clamp meter, longer and more dangerous as you are making connections into the cpc of the circuit is to put say a multi meter in series between the disconnected cpc & the earth bar. Please remember both of these will involve live working, to comply with statute law you must be competent to work live and there must be no other means of undertaking the work, if you are in doubt, and are not fully familiar with the process please don't do it.

*i believe they are all separated?

*not 100% sure if any any n's or e's are shared at this stage, still awaiting the client to pay for the additional cost, as all it was, was a board change and a periodic?

I would have thought that any faults should have shown up on the periodic first if done correctly thus the board change should have been a breeze.

My red above, hth

 

[neil19]

My red above, hth

hahaha thanks pal.

thats just it, all the tests on the periodic are fine???. when i changed the board and done all the tests, i walked away and everything was. until 24hrs later, when i get the call, and im still none the wiser. Ill try your suggestions. thanks again

---------- Post Auto-Merged at 18:29 ---------- Previous post was made at 18:26 ----------

one more? what should i be looking out for on the earth leakage tests, and maybe what diagnosis's?

My red above, hth

 

[Sidewinder]

The earth leakage tests are what the RCD will "see", you are looking for 0mA leakage, one other thing that has come to mind, have you ramped the rcd?

 

[batty]

Little confused why you also have 100mA TD Rcd also in circuit. I would be inclined to change Rcd's you may find with Wylex they are faulty.

 

[Evans Electric]

+1 with Batty

You don't need the 100mA main switch if you have dual RCDs .

And as Batts says... don't assume the RCDs are OK because they are new ....test them for 1/2 value trip before yoou go any further.