You can't spur more than one fcu from any socket...?

[Desmond.22]

Ok guys been asked help mate out but i think he has done his install wrong but as misplace my regs book cant find exact regulations he contravines.

Scenario is this big boiler room and pre existing metal clad sockets in ring final circuit. 32 Amp protection.

He has added 6 FCU metal clad wired in 2.5mm swa. Across 50M of the room at various places as a radial circuit.

Instead of running cable back to the board intends to spur the 6 FCU from the nearest socket of the ring final.

Ive told him im pretty sure you can't spur more than one fcu from any socket.

Am i right ? If so anyone know specifically which reg this is against.

I need to get regs book out but being mainly machine based maintenance guy i dont do that many installs but seems wrong to me.

Thanks guys

 

[Taylortwocities]

You may only have one spur from a ring final. Thats it. Doing what he is doing would mean a potential load of
13 x 6 amps (times 2 if they are double sockets).
He could have a hundred sockets from that one point on the ring final, but there would need to be a device limiting the max current (usually a 13A FCU).

This is implicit in the meaning of the regulation relating to overload current. IIRC this is reg 433. BS7671 does not specifically say you must not do this, but 433 means you cant.

It is stated as not being permitted in the OSG and Appendix 15 (for the hard of thinking).

 

[Pete999]

Ok guys been asked help mate out but i think he has done his install wrong but as misplace my regs book cant find exact regulations he contravines.

Scenario is this big boiler room and pre existing metal clad sockets in ring final circuit. 32 Amp protection.

He has added 6 FCU metal clad wired in 2.5mm swa. Across 50M of the room at various places as a radial circuit.

Instead of running cable back to the board intends to spur the 6 FCU from the nearest socket of the ring final.

Ive told him im pretty sure you can't spur more than one fcu from any socket.

Am i right ? If so anyone know specifically which reg this is against.

I need to get regs book out but being mainly machine based maintenance guy i dont do that many installs but seems wrong to me.

Thanks guys

One UNFUSED SPUR only is allowed, as many as long as they are connected to a FUSED SPUR which will be limited to13Amps in the FCU read Appendix 15 BS7671 FIG 15A not going to rewrite it in this pot suggest you read it yourself.

 

[littlespark]

How do you “misplace” a regs book? It’s huge!

As above, 1 unfused spur, or any number from 13A FCU.
Or, if 2.5mm, 20A radial from db

 

[Deleted member 105166]

How do you “misplace” a regs book? It’s huge!

I wonder what colour it is

 

[Desmond.22]

Blue one but share a workshop with 7 other guys and only on shelf so anyone can take and dont always get put back.

How is that comment helpful !

Anyway thanks for confirming what i thought

 

[Pete999]

One UNFUSED SPUR only is allowed, as many as long as they are connected to a FUSED SPUR which will be limited to13Amps in the FCU read Appendix 15 BS7671 FIG 15A not going to rewrite it in this pot suggest you read it yourself.

I wonder what colour it is

Sorry that should read, as many sockets as you like, can be wired from the FCU (depending on the loading) as the load will be limited to 13Amps.

 

[HappyHippyDad]

It would be ok if the first FCU feeds the rest of them from the load side of the FCU but not the supply side.

 

[Desmond.22]

It would be ok if the first FCU feeds the rest of them from the load side of the FCU but not the supply side.

That might be his get out as all powering very low current using equipment.

Think 1 amp fuses going in for the device.

Thanks guys

 

[Taylortwocities]

Low fuse in the device is not ok. Some time in the future, there will be a cold winter, and those sockets will be used for a few fan heaters…

 

[DPG]

Low fuse in the device is not ok. Some time in the future, there will be a cold winter, and those sockets will be used for a few fan heaters…

Think they are FCUs rather than sockets.

 

[Taylortwocities]

Think they are FCUs rather than sockets.

Ahh yes. No problem having a master FCU at the spur from the ring then…

 

[Deleted member 105166]

How is that comment helpful !

sorry buddy, was joking around, no offence intended.

 

[Desmond.22]

Low fuse in the device is not ok. Some time in the future, there will be a cold winter, and those sockets will be used for a few fan heaters…

Yeah but supply to the new radial be off a fused spur outgoing (load) side
[automerge]1567181869[/automerge]

sorry buddy, was joking around, no offence intended.

Ok mate

 

[davesparks]

Feeding six FCUs from a single spur from a ring is not allowed.
Feeding six FCUs from another FCU spurred from a ring is a pretty poor design although it is compliant.
The best option in my opinion would be to extend this back to a DB and create a new 20A radial circuit.

 

[Dustydazzler]

What are the 6 separate sfcu for ? Is the total load less than 13a

If yes you got lucky and can feed from the load side of the first sfcu.

If more than 13a is required follows daves advice and create a new circuit on its own circuit

 

[GeorgeCooke]

You may only have one spur from a ring final.

Wrong. You can have many spurs, even more than one from the same point, but each spur can only feed one socket outlet (single or double) or one FCU.

 

[DPG]

Wrong. You can have many spurs, even more than one from the same point, but each spur can only feed one socket outlet (single or double) or one FCU.

He means one spur from any one point on the ring final presumably.

 

[Devonchris]

Old thread here on that subject.
If it works.

 

[GeorgeCooke]

He means one spur from any one point on the ring final presumably.

Well that is allowed anyway.

 

[Taylortwocities]

I meant, as most know, you are not allowed as spur from an RFC and then add another spur from the first spur.

 

[Andy-1960]

See attached the diagram from the regs