Is this design exceptable for a Bathroom fan extractor.

Dartlec said:

I assume the feed is coming in from the FCU at the top right? Is the fan an on/off or a timed one? If timed you will want to be sure the switched and permanent live run to the fan.

If this is a bathroom, presumably that's not a standard ceiling rose but a suitable bathroom light?

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Dartlec said:

I assume the feed is coming in from the FCU at the top right? Is the fan an on/off or a timed one? If timed you will want to be sure the switched and permanent live run to the fan.

If this is a bathroom, presumably that's not a standard ceiling rose but a suitable bathroom light?

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brianmoooore said:

It's electrically OK, but it would be better to eliminate the junction box and take the feeds for the fan and the light back to the 3A switch/fuse.
There's no switch for the fan, so I take it that it's an automatic one with a humidistat?
You've labelled the pull cord "3 pole isolator". It's single pole and not an isolator with the wiring you show.. It's a switch

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Tonykakz said:

Is this what you mean i should follow.

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DefyG said:

A 3pole fan isolator could be used in place of the junction box to enable all poles to be isolated (it does what says on the tin!
The intermediate 3 pole isolator 'junction' would not be needed.

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Tonykakz said:

Is this what you mean i should follow.

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brianmoooore said:

As long as the 'fuse' also incorporates a DP switch (i.e. an ordinary switched fused connection unit), and is placed either inside the bathroom, (outside of the zones), or preferably, immediately outside of the bathroom door the triple pole isolator is not needed.
This circuit does not actually have a light included.

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brianmoooore said:

It's electrically OK, but it would be better to eliminate the junction box and take the feeds for the fan and the light back to the 3A switch/fuse.
There's no switch for the fan, so I take it that it's an automatic one with a humidistat?
You've labelled the pull cord "3 pole isolator". It's single pole and not an isolator with the wiring you show.. It's a switch

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Tonykakz said:

How is this design?

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Dartlec said:

That's almost right. (I assume we're ignoring earth for the purposes of the diagram but that it will be there)

The 2 core to the pull cord will be permanent live to and switched live back, so the feed to the light will need to come from the junction box, not the pull cord, so you have switched live and neutral to it.

Many fans don't have the requirement for a 3A fuse, assuming they are running from a 6A MCB, so sometimes it's easier to pick the fan more carefully.

It is also possible to do it with existing lighting wiring, with a Click Mode grid switch, which can contain an isolator and a fuse - or even an isolator and 2 fuses if you need to fuse feed and switched feed separately (though that needs a two gang wide switch).

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