Anyway of "damping" an MK Sentry circuit so cooker doesn't cut it out all the time?

[Jonathan]

Electric cooker, sealed element (ceramic hob, not the ring element) only 7
years old. Recently, if there is the slightest bit of moisture it trips the
RCB and the whole house goes out.

The wiring is a little scorched, but still looks sound, but sometimes it
also happens as the ring is turned OFF, which is odd. Can't find any shorts
or

The cooker fuse is MK LN5930 - I think this is the closest spec sheet.
http://www.tlc-direct.co.uk/Technical/DataSheets/MK_Sentry/RCDs.pdf

I can't find any mini rcb to replace the fuse, so the cooker doesn't black
the whole house out.

Meantime, is there some way I can "damp" that circuit, so it's a little less
sensitive?

 

[Michael Kennedy]

Is this some sort of GFCI breaker? Sounds like the cooker is finding another
path to ground. There is not any way to damp this you should either find the
fault or you could replace the GFCI breaker with a norman one. Probably not
a good idea since you say wires are scorched though. GFCI breakers monitor
the current going out on the hot wire and current returning on the neutral.
They are designed to shut off when the current supplied is not returning on
the neutral and is returning to ground somewhere else.

Exactly what kind of cooker is this?

I can't find any mini rcb to replace the fuse, so the cooker doesn't black
the whole house out.

What is a mini rbc?

- Mike

 

[Lurch]

Is this some sort of GFCI breaker? Sounds like the cooker is finding another
path to ground. There is not any way to damp this you should either find the
fault or you could replace the GFCI breaker with a norman one. Probably not
a good idea since you say wires are scorched though. GFCI breakers monitor
the current going out on the hot wire and current returning on the neutral.
They are designed to shut off when the current supplied is not returning on
the neutral and is returning to ground somewhere else.

Hmm, mainly pointless for uk.d-i-y.

Exactly what kind of cooker is this?

I would assume a UK one.

 

[Lurch]

Electric cooker, sealed element (ceramic hob, not the ring element) only 7
years old. Recently, if there is the slightest bit of moisture it trips the
RCB and the whole house goes out.

That would be RCD then.

The wiring is a little scorched, but still looks sound, but sometimes it
also happens as the ring is turned OFF, which is odd. Can't find any shorts
or

Doesn't have to be shorted, although I don't like the sound of "a
little scorched". How do you know it's sound, what did you test it
with.

The cooker fuse is MK LN5930 - I think this is the closest spec sheet.
http://www.tlc-direct.co.uk/Technical/DataSheets/MK_Sentry/RCDs.pdf

Fuse, or MCB, or RCD, or both, or all three?

I can't find any mini rcb to replace the fuse, so the cooker doesn't black
the whole house out.

Probably because RCB is a made up TLA.

Meantime, is there some way I can "damp" that circuit, so it's a little less
sensitive?

Possibly, but I think you'be better calling someone in who understands
electrics a little more clearly.

 

[Andy Dingley]

Meantime, is there some way I can "damp" that circuit, so it's a little less
sensitive?

You could replace the RCD - some do get a little "twitchy" with age.

Best approach though is to split-load the consumer unit. Some circuits
(sockets, shower) are RCD'ed, others (lighting, freezer, cooker,
immersion, welders, multi-hp machine tools, pottery kiln) aren't.

 

[Sam Goldwasser]

You could replace the RCD - some do get a little "twitchy" with age.

Best approach though is to split-load the consumer unit. Some circuits
(sockets, shower) are RCD'ed, others (lighting, freezer, cooker,
immersion, welders, multi-hp machine tools, pottery kiln) aren't.

If only this one device is causing problem, you should replace it or
have it professionally repaired. Otherwise, you're putting a bandage
on a cancer.

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no


If only this one device is causing problem, you should replace it or
have it professionally repaired. Otherwise, you're putting a bandage
on a cancer.

Not really, a fixed appliance with a bit of leakage on a non-TT system
is a non risk. And leakage on cooker elements is normal.

1. Is your installation TT?
2. If not, replace the CU with a split circuit one, with the cooker not
on an RCD.
3. There isnt anything you can do to the cooker to make it work more
reliably, other than bypassing the neutral switching on the user
controls if its 2 pole switched. Since it pops when switched off this
may be what youve got, and keeping N connected will normally prevent
that.

However as others have said, I would not suggest you personally rush
into the work, not until youre a fair bit clearer about this.

If its jsut one specific ring that does it, you could replace that one.
But you shouldnt need to, its just a badly designed insall. Whole house
RCDs are deprecated now - after being compulsory before of course.
(This excludes TT systems, which have ane extra issue requiring whole
house RCD cover - but that is now implemented rather better than
previously)


NT

 

[Andy Dingley]

If only this one device is causing problem, you should replace it or
have it professionally repaired.

Big electric heating elements are always going to have high leakage
currents.