Is this design exceptable for a Bathroom fan extractor.

[Tonykakz]

THIS IS FOR ELECTRICAL NEWS ONLY

 

[brianmoooore]

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

 

[Dartlec]

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?

 

[Tonykakz]

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?

Hi! Thanks . Would you be able to post an a design pic of what you are saying i should follow. Thanks for your time and help.

 

[Tonykakz]

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?

Whats confusing is the manufacturers demanding a FCU be fitted. Currantly the old fan runs on a light circuit with no FCU and islolator. I was going to just fit a 3 pole isolator at the pull cord. But if it requires a FCU i will need to redesign and incorporate the FCU. Thanks for your time and help.

 

[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

Is this what you mean i should follow.

 

[Tonykakz]

Is this what you mean i should follow.

Currantly the fan runs on light circuit.

 

[DefyG]

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.

 

[Tonykakz]

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.

Great! Thanks for the advice.

 

[brianmoooore]

Is this what you mean i should follow.

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.

 

[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...

 

[Tonykakz]

Tha

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...

Thanks for the advice . No RCD protection in the property. I also have the option of placing the RCD Spur outside the bathroom . I think from the edge of bath to wall is around 35 - 40 cm.

 

[Tonykakz]

Tha

Thanks for the advice . No RCD protection in the property. I also have the option of placing the RCD Spur outside the bathroom . I think from the edge of bath to wall is around 35 - 40 cm.

Just checked from bathroom edge to wall 100 cm.

 

[Dartlec]

Just checked from bathroom edge to wall 100 cm.

Although it would be OK more than 60cm from edge of bath, I'd personally put it outside where it's an option - that way you know all the wiring within the room has the protection - and also means it can be isolated/reset when necessary...

 

[loz2754]

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.

This is the view also taken by the NICEIC in their latest Connections magazine, published a few days ago. A 2 page article, ends with the conclusion that such RCDs do have a place, but should be noted on the certification as a departure.

 

[Tonykakz]

This is the view also taken by the NICEIC in their latest Connections magazine, published a few days ago. A 2 page article, ends with the conclusion that such RCDs do have a place, but should be noted on the certification as a departure.

What is noted on the certificate as departure mean?

 

[loz2754]

All electrical work should be accompanied by a certificate. This can be a minor electrical works certificate, or an electrical installation certificate.
The purpose of these certificates is to declare that the work complies with the regulations.
As the current version of the regulations does not support the use of RCD fused connection units, if you choose to install one, then you must record it on the certificate as a departure from the regulations.

 

[Tonykakz]

All electrical work should be accompanied by a

All electrical work should be accompanied by a certificate. This can be a minor electrical works certificate, or an electrical installation certificate.
The purpose of these certificates is to declare that the work complies with the regulations.
As the current version of the regulations does not support the use of RCD fused connection units, if you choose to install one, then you must record it on the certificate as a departure from the regulations.

certificate. This can be a minor electrical works certificate, or an electrical installation certificate.
The purpose of these certificates is to declare that the work complies with the regulations.
As the current version of the regulations does not support the use of RCD fused connection units, if you choose to install one, then you must record it on the certificate as a departure

Thanks .

 

[Dartlec]

This is the view also taken by the NICEIC in their latest Connections magazine, published a few days ago. A 2 page article, ends with the conclusion that such RCDs do have a place, but should be noted on the certification as a departure.

Thanks for pointing that out - I should probably read it a bit more often!

Useful that they've finally put something properly in print. Makes sense too. Now all we need is Napit to decide their viewpoint and there might even be agreement on something!

 

[Tonykakz]

Thanks .

The RCD spur unit in question . Is there any requirements as to what amps the MCB at the consummer unit should be . Or does that depend on the amps of the RCD spur unit it self, weather its 10 amp or 30 amp. Does that make sense? Morning all.

 

[Tonykakz]

Hi . When powering a bath fan from the main circuit and no longer from the light circuit how do you stop powering from the lighting once the new cable from fcu has been put in place. The wiring from the rose to the junction box is 3 core and earth. So i gather do you cap the neutral.wire to stop the powering of the fan ? And will this still switch the fan on and off via the pull cord but no longer power the fan. Thanks.

 

[Tonykakz]

Would there be a 2 core and earth from juntion box to rose in this diagram ?