Cable size

[golfpaul]

Outside lights are wired in artic flex, but has 2.5t&e from CU to FCU, about 30cm.

What size cable would you record on the schedule, the t&e or flex size?

 

[Guest111]

personally I'd record the 2.5 but make a note in the comments box re the flex.but no doubt others would have a different opinion.

 

[Brightspark2]

I'd put done the smallest CSA cable in the circuit...so if that's the flex, I'd put the flex down...

 

[trev]

What Brightspark said.

 

[cobrauk]

Well the test is for the supply circuit to the FCU, from it to outside is protected by that fuse not the mcb, after all you wouldn't class the flex as fixed wiring would you ?

 

[Brightspark2]

well the test is for the supply circuit to the FCU, from it to outside is protected by that fuse not the mcb, after all you wouldnt class the felx as fixed wiring would you ?

Ah I miss understood, I thought he meant the supply was in 2 different sizes...

As above then if the artic is on the load side of the FCU, then it's the T+E you record...

 

[davesparks]

The circuit which supplies the FCU gets recorded as 2.5
The circuit which originates at the FCU gets recorded as whatever size it is.
2 circuits, 2 lines on your test results sheet.

 

[davesparks]

Well the test is for the supply circuit to the FCU, from it to outside is protected by that fuse not the mcb, after all you wouldn't class the flex as fixed wiring would you ?

If the flex is part of a permanently connected installation and not just an appliance tail then yes it is classed as part of the fixed wiring.

 

[cobrauk]

well i was always told that flex is not to be used for fixed wiring but each to their own

 

[malcolmsanford]

Not sure where you heard that from but the regs allow you too . There maybe issues regarding terminations especially if the flex is fine but once again the BS 7671 comes to our rescue

 

[davesparks]

well i was always told that flex is not to be used for fixed wiring but each to their own

Ah yes the good old 'I was always told' a far more reliable source of information than any regulations or other official information. It's not a case of each to their own, it's a case of choosing the correct wiring system for a job. You wouldn't go clipping T&E along an outside wall to feed a PIR flood would you?

Years ago the regulations did not allow flex of more than 2M length to be installed but that went out before the 16th came along!

 

[Buzz-light-bulb]

The circuit which supplies the FCU gets recorded as 2.5
The circuit which originates at the FCU gets recorded as whatever size it is.
2 circuits, 2 lines on your test results sheet.

First time I have heard of having to use 2 lines on a test sheet for a circuit that has a fused spur, with a cable that has smaller csa. you do have a fairly good point, I would like to hear others opinions on this matter

 

[malcolmsanford]

I have to be honest and say that I personally have never recorded 2 results on a circuit such as this. The definition of a circuit in the 7671 does mention same origin and protected by the same protection devices(s)
So for instance on an EICR I would just put down the MCB at origin and R1+R2 at furthest point and Zs same.
If I were creating a spur of off an existing RF and issuing a MIEWC then I would test the cable from the spur making the BS 1361 the PD and the Zs on the new cable. I would most likely in the comments section note the spur was taken off the RF.

 

[davesparks]

First time I have heard of having to use 2 lines on a test sheet for a circuit that has a fused spur, with a cable that has smaller csa. you do have a fairly good point, I would like to hear others opinions on this matter

But it is not 1 circuit, it is 2.
The test sheet is not just a paperwork exercise, it is there to assist in verifying the installation is safe and compliant.
Part of that is ensuring that a fuse will operate in the correct time where it is protecting a cable.
If the outgoing side of a switch fuse is just an appliance flex then I wouldn't expect it to get a seperate entry on a test sheet, but where it is something like an external lighting installation then of course you do. More often than not it will be a minor works very though.

 

[Buzz-light-bulb]

Would you follow this same practice with an eicr ?