No earth in cable?

[pclayto]

Hi, I just have a quick query. I have a fused FCU, fed off the lighting circuit which supplies a bathroom cabinet with LED strip lights. The wire from the loft the the FCU is twin and earth. The bathroom cabinet LED driver is double insulated with no terminal for an earth wire. Does this mean the cable from the FCU is only a 2 pair cable without an earth? Is this right?

Thanks

 

[winston1]

You should use 3 core cable in case in the future you change the fitting for one that requires an earth.

You don't need a FCU on a lighting circuit, as such a circuit should already be fused at 6A. Most likely a FCU with a 3A fuse on a circuit with a 6A MCB, the MCB would trip first.

 

[RF Lighting]

Unless the manufacturers instructions require an FCU with a 3A fuse

 

[winston1]

Unless the manufacturers instructions require an FCU with a 3A fuse

And how would you conform to that elsewhere in Europe?

 

[RF Lighting]

Why would that matter?

 

[winston1]

Why would that matter?

As we know the fuse is not to protect the appliance, which should have its own internal protection, it is to protect the cable. For something that is sold in the EU that cable should be adequate for a lighting circuit so no further FCU is required.
Clearly that would be a case of the manufacturer being wrong. Also shows the stupidly of having to follow the manufacturers instructions regardless of whether they are correct or not.

 

[RF Lighting]

So you think you know what the manufacturer requires better than the manufacturer of their own product does? Perhaps they have designed the product to be protected by a fuse and that is why they say you must have one.

 

[ericmark]

Bathroom cabinet is a fixed appliance and as such the manufacturer can ask for protection to be provided else where. With a portable appliance yes the fuse in the plug only protects the cable but with fixed be it a oven, hob, immersion heater, extractor fan, or bathroom cabinet the manufacturer can and often does required protection for the unit to be provided by the installer.

As to question for a fixed appliance earth needs to be provided even if not connected.

 

[JohnW2]

Also shows the stupidly of having to follow the manufacturers instructions regardless of whether they are correct or not.

Maybe that's why they amended the regulation such that you no longer need to?

Kind Regards, John

 

[winston1]

Bathroom cabinet is a fixed appliance and as such the manufacturer can ask for protection to be provided else where. With a portable appliance yes the fuse in the plug only protects the cable but with fixed be it a oven, hob, immersion heater, extractor fan, or bathroom cabinet the manufacturer can and often does required protection for the unit to be provided by the installer.

Right, so what do you do in the rest of Europe where FCUs are not available (or as in France do no comply)?

 

[winston1]

Also shows the stupidly of having to follow the manufacturers instructions regardless of whether they are correct or not.

Maybe that's why they amended the regulation such that you no longer need to?

Kind Regards, John

Good move.

 

[EFLImpudence]

Bathroom cabinet is a fixed appliance and as such the manufacturer can ask for protection to be provided else where. With a portable appliance yes the fuse in the plug only protects the cable but with fixed be it a oven, hob, immersion heater, extractor fan, or bathroom cabinet the manufacturer can and often does required protection for the unit to be provided by the installer.

I disagree that that is the case with some of your examples but IF true, they should not.

Where they do, it is never clear why.

Bolting a hob to an oven does not alter the wiring of the oven.

 

[JohnW2]

.... the manufacturer can and often does required protection for the unit to be provided by the installer.

They can no longer 'require it' in the sense of it being necessary to comply with BS7671. I suppose that it's conceivably possible that the change in BS7671 will cause at least some manufactures to install appropriate protection within their products - since they can no longer necessarily rely on installers to provide that protection externally (as they used to have to do if they wanted to achieve compliance with BS7671). However, I'm not holding my breath!

Kind Regards, John

 

[Risteard]

such a circuit should already be fused at 6A.

There is no requirement for a lighting circuit to be protected with a 5/6A device.

 

[EFLImpudence]

I think winston meant would, not should.