Extractor fan with fused isolator

EFLImpudence said:

You still seem to be confused between isolators and switches.

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Still? It's my first post.

I know the difference, I possibly haven't explained clearly. We have four extractor fans:

Bathroom is both controlled and isolated with an isolator switch only. No timer. Can be turned on without the light.

Ensuite is triggered by a conventional lightswitch common to the light. It features an overrun timer. It can also be isolated with a separate isolator switch and light will still work.

Utility Room has no isolator switch. It doesn't work but appears to be controlled by a conventional lightswitch independent of the utility light.

WC has no isolator switch. Is triggered by a conventional lightswitch common to the light. It features an overrun timer.

Hopefully that explains better.

JohnD said:

If you own a screwdriver you can disconnect at the terminal block inside.

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No I know but the plan is to just swap it out at the same time with a motion activated PIR fan. Thanks for replying.

I feel like resurrecting this thread is like poking a hibernating beer, but hey ho, here we go!...

I've purchased the Manrose ceiling extractor and LED light (light only, I opted for the Envirovent Silent MV250/100T for my fan) and also run up against the 'requirement' for a 3amp double pole fused spur from the manufacturer. I tried to query with Manrose technical support as to whether the 3A fused spur is a requirement for just the fan, or also the light and got an unhelpful "the fuse would come at the beginning of the circuit so it would fuse both the fan and light". I bought the Scolmore three pole 3A fused spur isolator switch which I naively assumed would be a straight swap for the current isolator but then run into this (and other threads) about this switch which seems to raise as many questions as it does answers!
So, my related question - can I take from the previous comments in this thread that there is no safety requirement to have the LED light element wired via a "3A double pole fused spur" as suggested by the manufacturer? That whole light circuit is protected by a 6A RCBO, so I'd have thought that a like for like swap of the current LED lamp and SELV driver for the Manrose extractor LED lamp and SELV driver was perfectly safe without introducing another fuse?!

Runaround1878 said:

- can I take from the previous comments in this thread that there is no safety requirement to have the LED light element wired via a "3A double pole fused spur" as suggested by the manufacturer? That whole light circuit is protected by a 6A RCBO, so I'd have thought that a like for like swap of the current LED lamp and SELV driver for the Manrose extractor LED lamp and SELV driver was perfectly safe without introducing another fuse?!

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Without rereading all the thread, fuses RCBOs etc. are to protect the cable; not the appliance; therefore if the cable is adequately protected by the 6A RCBO then no more protection is required.

Then, of course, why would an additional switch be required and what good would it do and how would it affect the fan or light?

EFLImpudence said:

Then, of course, why would an additional switch be required and what good would it do and how would it affect the fan or light?

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I isolate my fan when I clean it of dust and fluff.

I could also do it if I needed to replace the fan.

That means I can do it with the light turned on.

This is quite common.

JohnD said:

I isolate my fan when I clean it of dust and fluff.

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There is generally no mention of fluff in the manufacturer's instructions.
Do you think that is why the manufacturer's instructions call for an isolator?
Why do the Wiring Regulations not call for an isolator for such things?

JohnD said:

I could also do it if I needed to replace the fan.

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You could indeed.
Do you think that is why the manufacturer's instructions call for an isolator?
Why do the Wiring Regulations not call for an isolator for such things?

JohnD said:

That means I can do it with the light turned on.

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You can.
Do you think that is why the manufacturer's instructions call for an isolator?
Why do the Wiring Regulations not call for an isolator for such things ?
How do you manage to mend the light?
Why do manufacturers not instruct that there should be two independent light circuits so you can mend the light with the light on?

JohnD said:

This is quite common.

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What is?


Do you think such things warrant the manufacturer demanding things which anyone is free to do should they so wish.

Could you not think of a good reason for the instruction demanding a fuse?

I fitted an isolator for the purposes mentioned.

I don't need a manufacturer to tell me it is safer to clean or replace a fan when it is isolated, and easier when the light is on.

You'll remember I quoted the question that I was answering.

EFLImpudence said:

Then, of course, why would an additional switch be required and what good would it do and how would it affect the fan or light?

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Thanks folks, the bear seems to have been awakened, but I've installed it without a new fused switch, such that fan and light were a direct one for one swap wiring wise.