25a Appliance on Unfused Spur off 2.5mm ring final with 32a RCBO

[mike42]

Hello All

Is this allowed?

 

[pete01]

No

 

[mike42]

Why not ?

 

[Murdochcat]

What is the appliance ?

 

[mike42]

I know ideally it should have a dedicated radial 25a rcbo/mcb in the board but wondering how bad it would be to run a spur off the existing ring. Instructions say "over current 25a" and you can see the plate (and what the device is) below....

 

[pete01]

13 amp max spur from a ring main, its supposed to be evenly loaded sticking 25 amps on one point may overload a leg.

See appendix 15 of bs7671, recommended items over 2kw have there own circuit

 

[pete01]

Thats not a 25 amp appliance its 9 amps, even so it need it's own supply if you want to do a proper job

 

[mike42]

Thanks a lot for the reply. I haven't got the full bs7671 and I'm not an electrician (hence asking on DIY site) but I do have the on site guide 2018 which in section H2.4 doesn't seem to say unfused spurs are limited to 13a ? Although section H2.5 does talk about it.

The plate seems to suggest the average usage is 9A but could peak a lot higher (presumably why the instructions talk about 25A over current)

I dunno bit of a nightmare if I have to run cable round the building just for this.

Ahhh hang on. Yes as you say its 9A - the other figures are output. So this could be put on a 13A fused spur I believe? Although strange why the insutrctions talk about 25A over current.

 

[pete01]

Thanks a lot for the reply. I haven't got the full bs7671 and I'm not an electrician (hence asking on DIY site) but I do have the on site guide 2018 which in section H2.4 doesn't seem to say unfused spurs are limited to 13a ? Although section H2.5 does talk about it.

The plate seems to suggest the average usage is 9A but could peak a lot higher (presumably why the instructions talk about 25A over current)

I dunno bit of a nightmare if I have to run cable round the building just for this.

Ahhh hang on. Yes as you say its 9A - the other figures are output. So this could be put on a 13A spur I believe? Although strange why the insutrctions talk about 25A over current.

Yes you could use a 13 amp spur on this occasion

 

[JohnW2]

Thats not a 25 amp appliance its 9 amps, even so it need it's own supply if you want to do a proper job

I don't even know where you get 9A from - does it not say 4.3A at 230V or 4.1/4.2A at 240V? What am I missing?

Kind Regards, John

 

[pete01]

I don't even know where you get 9A from - does it not say 4.3A at 230V or 4.1/4.2A at 240V? What am I missing?

Kind Regards, John

It says 9 amps at the top of the unit/rated current

 

[Taylortwocities]

Whssign

• Taylortwocities
• 16 Jul 2016

What he said

 

[JohnW2]

It says 9 amps at the top of the unit/rated current

So it does, and also says that the 'rated power' is 1.65 kW - but what do they mean, given that the bits below give the total input as 0.91 or 0.93 kW and 'total current' as 4.3A at 230V ?

Whatever, I think we can probably agree that, at least current-wise, there's no real problem in it being on a spur from a 32A ring?

Kind Regards, John

 

[pete01]

So it does, and also says that the 'rated power' is 1.65 kW - but what do they mean, given that the bits below give the total input as 0.91 or 0.93 kW and 'total current' as 4.3A at 230V ?

Whatever, I think we can probably agree that, at least current-wise, there's no real problem in it being on a spur from a 32A ring?

Kind Regards, John

Yep, I'll go with that mate

 

[Taylortwocities]

Yep, I'll go with that mate

Ditto