Manufacturer recommends 32amp breaker for 2kw appliance?

[stokielee]

Got to a customers house today after a brief discussion recently that they have brought a 2kw hob and it needs fittings. I went through the manufacturer’s instructions and they recommend it to be hard wired and that it is to be put on a 32amp breaker, obviously a 2kw appliance will pull around 8amps if my maths is correct so I am wondering am I missing something here? The hard wired part isn’t a problem, it’s more the size of breaker they recommend. There was 2x line and 2x neutral conductors too crimped together (this is where I first thought things weren’t what I am used to)

 

[James]

Are you sure it’s only 2kw in total?

 

[littlespark]

Can we have the model number of the appliance?

A lot of these are marketed for other countries as well as UK, where they have differing electrical supplies.
The MI can be misleading at times when things are written for one country, then badly translated.

 

[davesparks]

Is this a single ring hob, or otherwise smaller than usual appliance?

If it is a normal sized hob with 4(or more) rings then it's more likely the error is in the 2kW rating and not in the requirement for a 32A supply.

 

[stokielee]

Are you sure it’s only 2kw in total?

Yes 100% max output is 2kw

 

[Dartlec]

Sounds like this was designed for a European setup, where it would have been provided with a different cable that split maybe 1/2 the rings onto each of the L and N.

In which case 2kW for half of the rings sounds more plausible. Or possibly someone has misunderstood our regs about any fixed load with >2kW needing it's only circuit.

There certainly are hobs that are limited in output power by their control circuitry to never exceed a maximum power, but they usually come with a plug attached.

Unfortunately, Manufacturers Instructions do have weight in the regs, even when they are badly written or just plain wrong.

I'd probably consider the 32A requirement to be more binding than the stated power output in this case. What is there already? If it's replacing an existing hob then what is there is probably suitable.

 

[timhoward]

Whatever it says (which is likely wrong) I'd never fit less than 6 sq mm cable for a hob supply anyway as who knows what someone will want in the future. So it might be simplest to go belt and braces and feed from 32A breaker and at least 6 sq mm cable.

 

[mainline]

Got to a customers house today after a brief discussion recently that they have brought a 2kw hob and it needs fittings. I went through the manufacturer’s instructions and they recommend it to be hard wired and that it is to be put on a 32amp breaker, obviously a 2kw appliance will pull around 8amps if my maths is correct so I am wondering am I missing something here? The hard wired part isn’t a problem, it’s more the size of breaker they recommend. There was 2x line and 2x neutral conductors too crimped together (this is where I first thought things weren’t what I am used to)

32 amp breaker will be fine as the load is going to be no more than 2kw.

 

[stokielee]

Can we have the model number of the appliance?

A lot of these are marketed for other countries as well as UK, where they have differing electrical supplies.
The MI can be misleading at times when things are written for one country, then badly translated.

I am just waiting on confirmation from the customer that they brought the hob that they originally sent me for approval

Sounds like this was designed for a European setup, where it would have been provided with a different cable that split maybe 1/2 the rings onto each of the L and N.

In which case 2kW for half of the rings sounds more plausible. Or possibly someone has misunderstood our regs about any fixed load with >2kW needing it's only circuit.

There certainly are hobs that are limited in output power by their control circuitry to never exceed a maximum power, but they usually come with a plug attached.

Unfortunately, Manufacturers Instructions do have weight in the regs, even when they are badly written or just plain wrong.

I'd probably consider the 32A requirement to be more binding than the stated power output in this case. What is there already? If it's replacing an existing hob then what is there is probably suitable.

There was nothing there, I have managed to feed a 6mm cable in on a 32amp breaker as recommended

Whatever it says (which is likely wrong) I'd never fit less than 6 sq mm cable for a hob supply anyway as who knows what someone will want in the future. So it might be simplest to go belt and braces and feed from 32A breaker and at least 6 sq mm cable.

That’s what I have done in the end, it was just the 5 core and the 2kw that has thrown me out a little bit

32 amp breaker will be fine as the load is going to be no more than 2kw.

Of course, a fixed appliance should never pull more then it’s max load but why recommend a 32amp breaker for 2kw in the first place

 

[mainline]

Of course, a fixed appliance should never pull more then it’s max load but why recommend a 32amp breaker for 2kw in the first place

I can only guess at the reasoning as to why, maybe they do different power ratings but stick to the same cable/mcb.

 

[brianmoooore]

The 5 core flex indicates that this was designed to be connected to a 3 phase supply, but has been modified for the UK market. It's most likely 2kW per phase, so 4kW in total.
The doubled up 5 core flex is a better idea than the usual of brass links and then trying to fit 4mm2 cable to terminals designed for 1.5mm2.

 

[stokielee]

as

The 5 core flex indicates that this was designed to be connected to a 3 phase supply, but has been modified for the UK market. It's most likely 2kW per phase, so 4kW in total.
The doubled up 5 core flex is a better idea than the usual of brass links and then trying to fit 4mm2 cable to terminals designed for 1.5mm2.

Thank you, it’s starting to make sense now

 

[Lucien Nunes]

I agree that the 2kW is probably wrong, it simply isn't enough power for a normal, full-spec hob, Nor would 2kW require the two pairs of L&N terminals. As @brianmoooore explains, many European 3-phase domestic systems use two phases for the hob, typically limited to 16A each. But I don't think they would normally quote power per phase, so it's anybody's guess where the supposed 2kW rating came from.

 

[brianmoooore]

@stokielee You posted a pic of the English instructions. Could you post a pic of the French ones?

 

[littlespark]

@stokielee You posted a pic of the English instructions. Could you post a pic of the French ones?

Or the make and model of the appliance.