wire my electric cooker in?

[sar2012]

I have wired my electric cooker to the appropriate cooker socket. There are 6 wires - 2 black, 2 red and 2 yellow/green. The black wire it connected to the black wire in the wall in the cooker socket, the red to the red and the yellow/green to the yellow/green.
Problem is that when I have my cooker on at the same time as my computer, it trips the electric and anything that is plugged in turns off.
Has anyone any suggestions?

[dingbat]

Earth leakage. You are tripping the RCD. Could be the computer, could be the cooker.

Get an electrician in to test it for you.

[davy_owen_88]

dingbat wrote:

Could be the computer, could be the cooker.

Could be both

Does the RCD trip when using either the cooker or the computer on their own? If not an option is to get the cooker feed moved onto the non-RCD side (if there is a socket on the cooker switch change it to one without).

[JohnD]

Look at the thing that trips, and tell us everything that is printed/engraved on it please.

Everything.

If you can post a digital photo of the consumer unit that will be useful too.

[securespark]

You forgot, John... "We like photo's!"


PC's are prone to leakage, and if this leakage adds to other leaky appliances, it may pop the RCD. But you really need to check

a) the leakage to earth - put a mA clamp meter on the main earthing conductor

b) the ramp test result - to ensure your RCD is not tripping before it ought

__________________
As George Michael once said, "..if you're gonna do it, do it right, right?"

[RF Lighting]

I tend to ramp test the RCD with the appliance / wiring connected, and then again with nothing connected.

The difference in the two readings tells you the circuit leakage.

I tend to find my digital clamp meter is not very accurate at such a low current.

__________________
I downlights

[sar2012]

It’s got worse. It started tripping without the computer on whenever I turned the cooker on and now it is even tripped without turning the cooker on, just when I just turned the cooker switch on the wall socket on. I don’t know if it is wired up properly either (see above).

Here are the images of the fuse box and the tripping fuse:

[davy_owen_88]

Can you post a picture of the connections you have made at the cooker switch? Make sure there are no stray strands and that none of the conductors are touching the metal back box.

I would suggest calling in an electrician to perform some tests but checking the connections is a good start (make sure the power is off ofcourse).

Davy

[JohnD]

Thanks for the pics. We like pictures

The thing that is tripping is an RCD, which detects earth leakages and trips off. It is very sensitive, and does this before they get big enough, or last long enough, to be dangerous. BTW the RCD is not the culprit; it is detecting a fault elsewhere and switching off the power, which is its correct function - it is a safety device.

I see you have a very good quality Consumer Unit, although I see from the colour of the printing and the test label that it is about 10 years old. It is likely to still be in good condition, though. However I notice that it has "C" type MCBs fitted, which (although they fit) are an Industrial device - it may have been fitted by someone moonlighting on domestic work or using second-hand parts. In particular, the use of C10 for lighting circuits is likely to be incorrect in a domestic installation and would need to be justified by a design calculation which I suspect may not have been done. The MCBs can be swapped for a few pounds each. But this is not relevant to your presenting problem, so we will put it aside for the moment.

Q. Do you want to try to fix this yourself, or would you rather get an electrician in?

I think that probably you have some earth leakage on your cooker. This may be for example the oven element insulation breaking down with age (this is very common and not usually dangerous), or it may (less usually) be damp getting to something, perhaps as a result of cooking spillages, or a cable being damaged, for example by mice or having a heavy object on it. IF this is the case, there are two ways of dealing with it (1) have the cooker fixed (2) move the Cooker circuit to the RHS of your consumer unit (3) do both these things (best option). The circuits marked in Green are protected by the RCD, this provides an additional layer of safety for appliances that might be used outside or in damp conditions (including kettles and showers or other appliances that may get wet in use). the circuits in Red are not RCD protected, and this is usual for circuits which are not portable and likely to get wet. This includes lights and (usually) cookers. An electrician could move the circuit inside the consumer unit very easily.

A few easy tests you can try that will give us more information:
(Test 1) If the MCB (switch-like thing in the consumer unit marked "C32" and labelled "Cooker") is switched off (so the cooker circuit should seem dead) but the cooker control switch on the wall in the kitchen is "on" and the cooker knobs (including oven and rings) are "On"; does the RCD still trip?

(Test 2) If the MCB is "On" and the cooker switch on the wall is "off" and the cooker knobs are all on, does it trip?

(Test 3) If the MCB and the Cooker Wall switch are on, but all the cooker knobs are set to "off" does the RCD still trip?


(also, as Davy says, above - look for any signs of damage or loose wiring.
And tell us if there have recently been any alterations or events that might affect the wiring - including nails into walls or floor; mice; puppies; water leaks, or pulling the cooker out of position.

You say you have wired the cooker in, which sounds like you have done it recently; so we have to suspect a defect in the wiring such as a stray strand, or an incorrect connection; or a fixing screw coming into contact with a wire; or a fault on the cooker - is it new? Did you experience RCD trips with the previous cooker? Has the cooker been stored in a damp place?

Another point - does the Cooker Control switch on the kitchen wall have a socket built into it; and, if so, do you have anyuthing plugged into it? (if so, please unplug it).

[sar2012]

Here’s some history just in case but I don’t think it applies now:
The electric has been tripping intermittently for a few years and during this time (2004) my housing assoc. had an electrician out about it:
· The RCD Tester showed low voltage coming through my cables: The P.S.C. test showed that the supply was fluctuating between 224 and 229, mainly 226.
· My electricity supplier said regulations had changed and they were supplying an appropriate supply.
· Electrician thought there might be a problem with either the electricity metre or the fuse head.
I didn’t keep all notes so can’t remember everything they did but a wire to my electric circuit had to be repaired, the clicking noise through my phone stopped and the loud buzzing from the fuse box stopped.
However the tripping continued but less often and only usually when I was using the cooker, e.g. I couldn’t use all the cooker lights at once or it would trip.

Anyway that’s the history and might have no bearing on the present situation.

The present situation is that recently, after reconnecting the wires (they were disconnected after moving the cooker to clean under it) the problem became much worse to where it is now tripping just by switching the cooker wall socket switch on.


Here’s the picture of the cooker connection wires, are they wired correctly? And pictures of the interior and exterior wire socket cover and the cooker wall switch (which I’ve unplugged the kettle from):

[JohnD]

Good grief!

[dingbat]

My thoughts, exactly, John.

[sar2012]

I tried the cooker with the wiring left exposed as in the picture above and it works without tripping. I’m going to do the 3 tests before fastening it up and then again after I fasten it all up and see when it trips.

[plugwash]

were the wires actually in the the terminals of the plate before you took it off?

[bernardgreen]

Remove the two spare silver screws from the plate before putting the wires into the terminals.

Otherwise they may at some later date fall out and short between box and a terminal

And there should be an earth connection to the metal box