Power supply for a 5kW (14.6A) multi outdoor A/C - is a dedicated circuit required?

[Andy™]

the spur current (and fuse) can be up to 20A

you can't get a 20a fuse for a spur

 

[jimmybb]

you can't get a 20a fuse for a spur

https://uk.rs-online.com/web/content/discovery/ideas-and-advice/fused-spurs-guide#
?

 

[Andy™]

https://uk.rs-online.com/web/content/discovery/ideas-and-advice/fused-spurs-guide#View attachment 15622
?

BS1362 fuses (that would be used in a fused spur) only go to 13a. if you do find a 20a BS1362 fuse then its a fake fuse that probably won't blow

 

[johnb2713]

BS1362 fuses (that would be used in a fused spur) only go to 13a. if you do find a 20a BS1362 fuse then its a fake fuse that probably won't blow

Try the fused spur with a 13amp fuse, if it pops the fuse on a regular basis then you need the dedicated feed, if it runs ok then youre sorted.

 

[BorisJ]

It is a regulation recommendation that any electrical device greater than 2kw is connected via its own circuit.

Whilst the item may run at lower than this there are times that it would run at or near too it’s max.

No it is not a reg. It is in the on site guide and is someones personal recommendation only.

 

[BorisJ]

if MI's require minimum of 15.8a then it'll need its own circuit. would it work on a 13a spur? probably. would it be compliant? no

Under what reg no would it not be compliant?

 

[binky]

Ok thanks. FWIW I think binky's point is right, the spur current (and fuse) can be up to 20A particularly if the appliance isn't expected to use this much current for long periods.


View attachment 15620

I know I'm right, although the wife doesn't agree with that

 

[Sharpend]

No it is not a reg. It is in the on site guide and is someones personal recommendation only.

Ok Boris; let’s say that Bs7671 are the regs and the On-site Guide is considered as an influence towards best practice, so if you wish to choose an alternative method feel free, it’s your design not mine. I just think that it is generally easier to follow best practice as saves a lot of unnecessary questions should an issue arise.

 

[binky]

Ok Boris; let’s say that Bs7671 are the regs and the On-site Guide is considered as an influence towards best practice, so if you wish to choose an alternative method feel free, it’s your design not mine. I just think that it is generally easier to follow best practice as saves a lot of unnecessary questions should an issue arise.

I have to say I regard the OSG as dumbed down regs and not overly worth looking at.

 

[BorisJ]

https://uk.rs-online.com/web/content/discovery/ideas-and-advice/fused-spurs-guide#View attachment 15622
?

Typical incorrect manufacturers blurb. The 20 amp one is a flex outlet plate with no fuse.

 

[poni]

Below is from their web page , as has been said before they do not make BS 1362 20A fuses, RS have listed it wrong ,

Typical incorrect manufacturers blurb. The 20 amp one is a flex outlet plate with no fuse.

​

​

20A Double Pole Control Switches​

The MK Electric Albany Plus range of switches features stylish curved design, the double pole switches are manufactured from the finest materials and maintain their high quality appearance for years to come. The terminals in the back of these 20A switches have a funnel entrance and are upwards facing, to make installation easier.

 

[binky]

Below is from their web page , as has been said before they do not make BS 1362 20A fuses, RS have listed it wrong ,

​

​

20A Double Pole Control Switches​

The MK Electric Albany Plus range of switches features stylish curved design, the double pole switches are manufactured from the finest materials and maintain their high quality appearance for years to come. The terminals in the back of these 20A switches have a funnel entrance and are upwards facing, to make installation easier.

they aren't fused just rated for 20Amp load

 

[Murdoch]

The last one of these I saw was spurred off the socket circuit with no OCPD other than the 32A MCB

 

[poni]

they aren't fused just rated for 20Amp load

yes I agree

The last one of these I saw was spurred off the socket circuit with no OCPD other than the 32A MCB

You can do this , as long as the load is 20Amp or less ( cable needs to be the same as the ring, (remember the fuse is there to protect the cable not the appliance))

 

[Murdoch]

You can do this , as long as the load is 20Amp or less ( cable needs to be the same as the ring, (remember the fuse is there to protect the cable not the appliance))

no isolation either other than the MCB ....... poor design, poor installation........ on a shared RCD too