Is this design exceptable for a Bathroom fan extractor.

[Vortigern]

You can purchase a fused three pole isolator as well.

 

[Tonykakz]

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.

Yes this circuit is from thr mains power and is not powered by lighting circuit . Thanks .

 

[Tonykakz]

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

How is this design?

 

[Dartlec]

How is this design?

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).

 

[Tonykakz]

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).

Thanks thats great! Yes earthing was ommitted for diagram. Click mode gride switch. Need to look into that to.

 

[Dartlec]

Thanks thats great! Yes earthing was ommitted for diagram. Click mode gride switch. Need to look into that to.

One of these along with one of these can fit into a single gang 3 grid front - so if you can tap into the wiring before it gets to the switch that covers things.

If not, then you can get the isolator and 2 fused spurs into a two gang front

Just depends which is easier in the circumstances really - if there is RCD protection on a local socket circuit but not the lighting then the switched FCU method as you've drawn is a neat way to ensure the required RCD protection on the fan and bathroom light.

 

[Tonykakz]

One of these along with one of these can fit into a single gang 3 grid front - so if you can tap into the wiring before it gets to the switch that covers things.

If not, then you can get the isolator and 2 fused spurs into a two gang front

Just depends which is easier in the circumstances really - if there is RCD protection on a local socket circuit but not the lighting then the switched FCU method as you've drawn is a neat way to ensure the required RCD protection on the fan and bathroom light.

Thanks for all your help . Much appreciated.

 

[Tonykakz]

Thanks for all your help . Much appreciated.

Is this fused spur RCD protected ok to install in bathroom safe zone? Morning.

 

[Tonykakz]

Is this fused spur RCD protected ok to install in bathroom safe zone? Morning.

Also is it safe to run surface mounted pvc trunking in zone 2 in the bathroom?

 

[Dartlec]

Is this fused spur RCD protected ok to install in bathroom safe zone? Morning.

Any of the 'standard' fittings like this are regarded as IP20, which can't be used in zone 1 or 2 (so up to 60cm from the side of the bath). Outside of that they are ok for general use in a bathroom as long as they are not likely to be sprayed with water.

PVC trunking is OK in zone 2 to run cables through, though it shouldn't have any joints within it as it doesn't have an IP rating for water resistance (that I know of).

There is an extra wrinkle here though - the RCD spur you show is currently not listed in the Wiring Regulations as an acceptable way to add 'additional protection' in a bathroom, though there is conflicting information as to whether this was an error or deliberate.

Some people would say that means it can't be used on new installations to comply, but requires a more traditional RCD or RCBO protection

I still take the view that there are places where it is reasonable to use it, though adding more traditional RCD protection is a better option when it's available.

Is there any RCD protection in the property?

One final point - any work within the zones in a bathroom is notifiable under the Part P Building Regulations scheme, which generally means it has to be done by a registered person in the competent schemes.. There are other ways by notifying it yourself, but they can be costly...