Oven connected into ring - EGBR says this is ok?

[Flanders]

Thanks Flanders,

You're right it may affect the warranty but I just couldn't leave the 2.5mm on there knowing it was only protected by a 32A MCB. I cant see anything wrong with replacing smaller cable for bigger? Just seems crazy charging the lady hundreds of pounds for a new circuit when this is safe!

Yes the circuit is safe but...
The Hob is still protected by a 32 amp fuse so if there was a fault then would the internal wiring/connection unit cope with extra load before the MCB trips.

I have a 20 amp MCB protecting my hob and never had a problem

 

[GLENNSPARK]

Yes the circuit is safe but...
The Hob is still protected by a 32 amp fuse so if there was a fault then would the internal wiring/connection unit cope with extra load before the MCB trips.

I have a 20 amp MCB protecting my hob and never had a problem

the fuse/breaker protects the cable..
Happyhippy....crack on..its OK...

 

[Geoffsd]

Yes the circuit is safe but...
The Hob is still protected by a 32 amp fuse so if there was a fault then would the internal wiring/connection unit cope with extra load before the MCB trips.

How will a hob overload the circuit?

I have a 20 amp MCB protecting my hob and never had a problem

Precisely.

 

[HappyHippyDad]

A appliance actually stated to fuse it down to 23A?

Yes G, it really did say that, I'm not one to exagerate. You are one of the more experienced forum users and I would genuinely appreciate to hear what you would have done?

6mm cable fed from a 32A MCB to 45A cooker switch which splits (with 6mm) to a socket for oven (approx 2.5KW) and hob 5KW (which had 2.5mm flex attached).

Nearly all of them are. You don't need a new circuit.


4mm would do. Actually 2.5mm would probably do but that would require knowledge and test equipment.


Does it?

OPDs are there to protect the cable, not appliances.


No. Do you think you should be doing this work?


You'd think there would be tradesmen around who knew how to do this sort of thing.

Goodness me, what if it was a COOKER with hob and oven stuck together?

Yes :winkiss:

 

[Flanders]

How will a hob overload the circuit?


Precisely.

As stated the hob should be protected By a 23 amp fuse So I would say that if there is a fault with the Hob the internal wiring and terminal block of the hob can safely run at up to 23 amps were as the only over load protection for the hob is 32 amps So yes the circuit will take the load but will the Hob ??

 

[SPARTYKUS]

use diversity here...
if its 3KW...then you can usually knock a KW off it....
think about it....if the oven has a grill...then the internal wiring will dictate that both grill and oven will not be on at once....

yo Glenn

got caught out with this tuther day, they had a big posh cooker (4k) that came with its own 10mm2 3core heat resistant flex on it - turns out you can have the grill onat the same time as the oven.


for.....

PIZZA!!!

 

[GLENNSPARK]

As stated the hob should be protected By a 23 amp fuse So I would say that if there is a fault with the Hob the internal wiring and terminal block of the hob can safely run at up to 23 amps were as the only over load protection for the hob is 32 amps So yes the circuit will take the load but will the Hob ??

explain please which wholesalers i could get a 23A fuse from....
i want one for my collection...

 

[GLENNSPARK]

yo Glenn

got caught out with this tuther day, they had a big posh cooker (4k) that came with its own 10mm2 3core heat resistant flex on it - turns out you can have the grill onat the same time as the oven.


for.....

PIZZA!!!

the cable CSA would give the game away eh sparty....

 

[HappyHippyDad]

yo Glenn

got caught out with this tuther day, they had a big posh cooker (4k) that came with its own 10mm2 3core heat resistant flex on it - turns out you can have the grill onat the same time as the oven.


for.....

PIZZA!!!

I cant believe you are replying to this when Han Solo is at this very moment fleeing the imperial fleet!!!

 

[Leckie]

Is overload protection required for a resistive load such as a hob? The flex should not have been removed I suspect. Fault protection is of course required.

 

[DieselShunter]

Sorry just realised you took the flex of hob This might affect the warranty.

It might. But it won't affect your statutory rights, which are nearly always more effective than a warranty. Warranties, especially 12 month ones, are usually there to browbeat you into foregoing your rights under the SoG act.

 

[Geoffsd]

As stated the hob should be protected By a 23 amp fuse

That is presumably a misprint. Do you think, perhaps it should be 13?

Cooking appliance manufacturers state either:
It must be protected by a certain fuse - because that is needed to protect the (cheapest) flex they have fitted.
Or, without flex, it requires a certain amperage of supply - because that is required for it to work.

So I would say that if there is a fault with the Hob the internal wiring and terminal block of the hob can safely run at up to 23 amps

It will obviously be designed for its maximum load, whatever that is.

whereas the only over load protection for the hob is 32 amps

The hob cannot overload.

So yes the circuit will take the load but will the Hob ??

Neither it nor the cable will have to. Overload cannot happen.

Do you think the cabling inside cookers protected by a 30A BS3036 is all capable of carrying 42A, i.e. 6mm?

 

[Guitarist]

Yes G, it really did say that, I'm not one to exagerate. You are one of the more experienced forum users and I would genuinely appreciate to hear what you would have done?

6mm cable fed from a 32A MCB to 45A cooker switch which splits (with 6mm) to a socket for oven (approx 2.5KW) and hob 5KW (which had 2.5mm flex attached).


Yes :winkiss:

Well, for a start, I would contact the manufacturer directly and ask them where I can obtain this mythical 23A fuse. Sounds like they have simply decided that 5kw is about 23A, so that should do, without allowing for any diversity.

 

[SPARTYKUS]

I cant believe you are replying to this when Han Solo is at this very moment fleeing the imperial fleet!!!

Autopilot

 

[Flanders]

1. That is presumably a misprint. Do you think, perhaps it should be 13?

2. Cooking appliance manufacturers state either:
It must be protected by a certain fuse - because that is needed to protect the (cheapest) flex they have fitted.
Or, without flex, it requires a certain amperage of supply - because that is required for it to work.

It will obviously be designed for its maximum load, whatever that is.

3 The hob cannot overload.

4 Neither it nor the cable will have to. Overload cannot happen.

5 Do you think the cabling inside cookers protected by a 30A BS3036 is all capable of carrying 42A, i.e.
6mm?

1 .How can it be 13 amps when the unit is ratted a 5KW (about 22 amps at 230or 21 amps at 240) Apply a bit of diversity and a 20 amp MCB will be fine

2. So your saying the fuse is to protect the Flex not the appliance from overload ?

3. Why cant the Hob Over load??

4. So there was no need to change the cable to 6mm If the Hob can't overload ?

Here an example for you
There was 32 amp fork lift truck charger plug into a 32 amp socket protected by a 32 amp MCB , all ok
But then the folk truck charger was replaced by someone with a 16 amp ratted unit,using the same flex and 32 amp socket and was still and protected by the same 32amp MCB.

There was a fault on the fork lift charger coursing it to catch fire.
The customer asked why it did not trip the MCB first .
I told them it was because the MCB was overrated for the charger unit. Are you telling me that this was not the case ?


5. never though about that You may have a point

 

[Geoffsd]

1 .How can it be 13 amps when the unit is ratted a 5KW (about 22 amps at 230or 21 amps at 240) Apply a bit of diversity and a 20 amp MCB will be fine

We don't know. Perhaps the loads add up to 5kW but only 3kW can be switched on at once.

2 So your saying the fuse is to protect the Flex not the appliance from overload ?

Yes, definitely.

3 Why cant the Hob Over load??

It is a fixed load. It can't suddenly start drawing more current.

4 So there was no need to change the cable to 6mm If the Hob can't overload ?

No. 433.3.1.2(ii)

Here an example for you

Therewas 32 amp fork lift truck charger plug into a 32 amp socketprotected by a 32 amp MCB , all ok
But then the folk truck charger was replaced by someone with a 16 amp rated unit, using the same flex and 32 amp socket and was still and protected by the same 32amp MCB.

There was a fault on the fork lift charger coursing it to catch fire.
The customer asked why it did not trip the MCB first .
I told them it was because the MCB was overrated for the charger unit. Are you telling me that this was not the case ?

It may be different if someone has fitted the wrong plug to the charger and the charger is supposed to be protected by the MCB.

5 never though about that You may have a point

 

[Flanders]

So can there not be a fault with an appliance that courses an over load for example leakage to earth or neutral (not a dead short) I thought the fuse in the plug top were there to protect it ?

And Did you mean Reg 433.3.1(ii)

 

[Sparky Ninja]

It would cause an overcurrent called fault current.
An overload current will only occur in an electrically sound circuit.

 

[Flanders]

It would cause an overcurrent called fault current.
An overload current will only occur in an electrically sound circuit.

So the fuse is there to protect from Fault current, if there was a fault current coursed by the Hob would the 32 amp MCB trip out before any damaged is coursed to the Hob

 

[Geoffsd]

So can there not be a fault with an appliance that courses an over load for example leakage to earth or neutral (not a dead short) I thought the fuse in the plug top were there to protect it ?

That is not an overload but a fault current which will operate the 32A MCB in 0.1s. or less.

As long as the cpc can cope with fault current then all is well.
Hence the link to 434 in 433.3.1(ii) and my reference above to knowledge and test equipment.

A current leakage enough to overload a, say, 2.5mm conductor but not operate the 32A MCB would have to be very specific indeed - around a constant 6, 7 or 8Ω.
This isn't really possible, is it?, and we do not have to cater for it.
Such a fault would melt the internal wiring or element wire first anyway.

And Did you mean Reg 433.3.1(ii)

Yes.