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Sparky question. Bathroom fans, isolators and fuses
cliftyhanger - 30/10/17 at 08:16 AM

In a rental property the sparky I have instructed has flagged up that the bathroom fan is on an isolator switch not a fused spur. I think this requirement changed a few years ago? and as nobody can verify the age of installation it seems a change is required.
But as the isolator has 2 lives (perm plus a switched) does this get replaced by 2 fused spurs? Access to the wiring is limited so I don't think it will be easy to just fuse the feed to the bathroom. I am hoping this can be done with a simple swap....

As I have a few other places that are similar, I am thinking ahead too!

And while I am on the sparky type questions, the twin RCDs in the consumer unit trip together. I assume this is because the 2 have not been separated? on the CU?? At this point I need to thank my dear Dad who owns the property, and obviously got stitched up when much of the work was done.... He probably paid too much, and never got any paperwork at all it seems


And to top it off the sparky I instructed to do the test has suddenly decided to get a permanent job, and is proving hard to get hold of now he has been paid for the inspection. Typical!

Cheers
Clive


nick205 - 30/10/17 at 09:40 AM

Have you anything to lose by asking a 2nd sparky to look at/quote the work required?


cliftyhanger - 30/10/17 at 11:04 AM

The rental agency are struggling to find somebody reliable to use.
I have access to a "jobbing electrician" who has zero qualifications, but spends most of his days working for other electricians and they then sign the work off (he does all the actual work, they then test etc and make all the money it seems!)

I will see if I can nail him down, he may be able to get somebody to re-test once all the remedial work is done....


SteveWalker - 30/10/17 at 11:51 AM

Unless things have changed again, bathroom fans are normally fed from the lighting circuit and require an isolator, but not an FCU - unless the manufacturer of the fan calls for 3A fusing. Check the fan details before accepting that an FCU is required.


peter030371 - 30/10/17 at 01:33 PM

I had a bathroom fan fitted in my extension last year and that is on a simple (twin) isolator with the power feed coming from the lighting circuit. I really can't see why you would need a fused spur for it but you do need a twin pole isolator for wiring regs.


cliftyhanger - 30/10/17 at 03:00 PM

The regs changed as most fans are rated at 3A, and apparently there have been some fires.
So now if the fans want 3A, you MUST have a 3A spur in there, and that means before the light fitting. So you can't have the light on while swapping a fan!
I was wondering if somebody would start selling a twin fused isolator, which is what it ideally needs as a direct replacement.

I will have a look at the fans, see what make etc they are and if they need a 3A fuse. I hadn't thought to check that.


peter030371 - 30/10/17 at 03:18 PM

quote:
Originally posted by cliftyhanger
The regs changed as most fans are rated at 3A,


Are they? A quick look on screwfix and they are all less than 20W, the better manufactures are less than 10W.


ReMan - 30/10/17 at 04:05 PM

quote:
Originally posted by peter030371
quote:
Originally posted by cliftyhanger
The regs changed as most fans are rated at 3A,


Are they? A quick look on screwfix and they are all less than 20W, the better manufactures are less than 10W.


I thought 3 A seemed a lot, . I expect that would power something big enough to inflate a bouncy castle


SteveWalker - 30/10/17 at 04:29 PM

3A is not the fan's power requirement. It is the rating for the fuse protecting its cable and internal wiring. If the manufacturer specifies 3A then a 3A fuse is required, but if they do not, then feeding directly from the (normally 6A) lighting circuit is fine.


peter030371 - 30/10/17 at 04:41 PM

quote:
Originally posted by SteveWalker
3A is not the fan's power requirement. It is the rating for the fuse protecting its cable and internal wiring. If the manufacturer specifies 3A then a 3A fuse is required, but if they do not, then feeding directly from the (normally 6A) lighting circuit is fine.


That makes a bit more sense..the fans I have got in the past were Vent Axia Silent fans and rated at 6.8W max and no mention of what fuse rating to use. Might be easier to change the fan than the wiring for the OP


big-vee-twin - 30/10/17 at 05:42 PM

Why not just change the consumer unit MCB to 3 amps?

Do a quick tot up of whats connected and see if it will go on a 3 amp device.


cliftyhanger - 30/10/17 at 06:16 PM

quote:
Originally posted by big-vee-twin
Why not just change the consumer unit MCB to 3 amps?

Do a quick tot up of whats connected and see if it will go on a 3 amp device.


Now that is a plan! I like you thinking. Now everything is low energy, bulbs are never over 10watt. So 3A will do loads of them. And I reckon total draw will be well under 2A...probably under 1A (from memory 5x std LED bulbs=30w, 2 bathroom fans =40w, 2 bathroom lights, call that 40w, think that is it!

That will be an easy solution.

Thank you for your lateral thinking.