Rayburn 480k - trips electrics

[Rachel Williams]

We have recently had a new consumer unit fitted as part of new extension electrical work. Since then the Rayburn (which had been fine previously) has tripped the electrics such an that we cannot use heating/hot water at all. It is 10 months since the last service. The heating trips electrics immediately when turned on while the cooker does it either after 5-20mins or when turned off.

Our electrician thinks it’s a Rayburn issue. Our heating engineer thinks it’s electrical. He disconnected supply to pump, zone valves, burners etc to try to establish at what point it tripped. He said that there is a possibility it could be the programmer as it is immediate. However, there is the co-incidence that all was fine until the new consumer unit was installed.

Any thoughts and comments would be very welcome.

 

[Lectrician]

Your electrician should know how to use an insulation resistance tester, and this will show him where the fault is. If the Rayburn previously had no RCD protection, and now does, there is every possibility that a fault would of gone undetected until the RCD was introduced.

A decent electrician should be able to track down the cause of tripping.

Has your electrician given you a certificate with test results yet? Can you photograph this? Can you photograph your new CU?

 

[Rachel Williams]

Thanks for your reply Lectrician. I’m not sure whether it previously had no rcd protection. The previous consumer unit and Rayburn were installed in 2003 when the house was built.

The electrian still has more work to do on consumer unit and electrics in house in general, but Rayburn trips are obviously in. Picture of unit uploaded. The Rayburn is the one (or two - I can’t remember) next to the main switch.

Electrician has ordered a ‘c grade trip’ to try in the new unit. Not sure whether he has used insulation resistance tester. Will ask him.

Any further thoughts?

 

[ban-all-sheds]

What's tripping - the RCD or an MCB?

 

[bernardgreen]

What's tripping - the RCD or an MCB?

BAS ..... An RCBO does not indicate whether it tripped due to over current or due to earth leakage.

 

[ban-all-sheds]

Indeed.

And if I'd remembered what was in the photo I'd looked at only about 10 minutes earlier I'd have known they were RCBOs not MCBs.

 

[ericmark]

Many heating appliances use mineral insulated heaters which can draw in moisture from the atmosphere, this will cause a RCD (A RCBO has a RCD built into it) to trip. Most likely it is a moisture problem which is down to fault on Rayburn.

However also it is easy to put a wire in the wrong hole so it could be the wiring, "the cooker does it either after 5-20mins" points to Rayburn, the RCD works within 40 mS so it seems likely as the cooker is switched on moisture is driven from one place to another causing it to trip.

As said the answer is to use meters to locate the fault, not simply guess, there are some dangerous methods used to dry out the elements, however even if dried out, every time the appliance is left unused for a time the moisture will get back in, so only real cure is to replace the faulty elements.

It sounds like an earth - neutral fault when it trips without turning it on. So only way is usually to open the appliance and test each element, as all neutrals are left connected only the line is switched. You can't test by simply switching on/off, it needs neutrals disconnecting to find which element is faulty.

"Our electrician thinks it’s a Rayburn issue. Our heating engineer thinks it’s electrical." well clearly is an electrical fault, it is where the fault is, "think" is not good enough, it only takes a few minutes with meter and they will know.

 

[ban-all-sheds]

The Rayburn is the one (or two - I can’t remember) next to the main switch.

 

[Nozzle]

It could be there fault in the Rayburn was there all along - but the old CU was too tollerant of it and did not trip, unlike your new one. There's plenty of cabling you can check hidden behind the louvred panel at the front, and inside the bottom left door beside the burners. Turn it off, check all the cables for worn or burned insulation. Next up, check behind the thermostat panel top left door and again look for damaged wires or anything crimped behind a screw head.

Nozzle

 

[JohnD]

this appears to be an appliance that also runs the CH. Very often there is water-related earth leakage from the circulating pump or motor valves.

The oven elements are very prone to causing RCD trips, but only when the oven is turned on. So that should be the easiest to isolate. If it's an oil-fired Raeburn then it will tend to be warm lost of the time, which should dry out dampness. Unless it has a water leak.

 

[flameport]

Electrician has ordered a ‘c grade trip’ to try in the new unit.

That will achieve nothing.

Not sure whether he has used insulation resistance tester.

Highly unlikely given the state of that consumer unit.

Any further thoughts?

This 'electrician' is nothing of the sort.
Why are there cables coming out of the front of the consumer unit?
Why is that mess even energised - there are live parts just inside those holes where circuit breakers or blank plates should be installed.
Did this person arrive on a horse?

There are no circumstances where this shamble is acceptable:

 

[ban-all-sheds]

Why are there cables coming out of the front of the consumer unit?

I wondered that.

Reasoned that they are for circuits yet to be connected in the CU.

TBH, apart from (as in "Apart from that, Mrs Lincoln, how did you enjoy the play?") the gaping holes it leaves it's not a bad way to avoid unterminated cables floating around inside the CU in circumstances where they can't be left not yet brought into it.

 

[JohnD]

A result of putting the CU tight up to the ceiling.

I remember seeing the post-fire photos where a DB had been installed like that, and during a fault, the smoke and heat simply rose into the ceiling void and ignited the accumulated dust, followed by the joists and the studwork walls on the several floors above, and the whole house.

If it had passed into the room rather than a void, it would have set off a smoke detector.

 

[Lectrician]

CU looks like it’s been fitted a little early.

It looks like RCBOs, so I would assume it’s tripping due to earth leakage. A C type would not cure that.

 

[chivers67]

I've never seen work in progress New "Temporary" Electrical installations done like this ever in all my years. How very odd, the Wall or Ceiling hasn't got a speck of plaster on it, the CU will obviously have plaster round it but why not utilise the knock outs so it it will be easier to install the cables when they become "permanent"?

When the ceiling/plasterboard above is plastered the cover won't be easy to get off without disturbing it?