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Topic Title: Bathroom fan isolators
Topic Summary: Are they required?
Created On: 22 April 2013 09:27 AM
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 22 April 2013 09:27 AM
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Grumpy

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Joined: 09 January 2009

I am aware of a requirement to be able to isolate rotating machinery for maintenance and have always thought it a bit silly for bathroom fans as the only maintenance I do is swap them out. However, having been to a job where one caught fire I can see that there might be some instances where being able to instantly isolate them has some appeal. I've searched the forum and opinion seems to be divided. Does anyone have a definitive on this please? I was prompted to enquire by an EICR where the fans in all four bathrooms don't have isolators and I am unsure whether this is a requirement or good practice. Thanks.
 22 April 2013 09:37 AM
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Jaymack

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Originally posted by: Grumpy
I was prompted to enquire by an EICR where the fans in all four bathrooms don't have isolators and I am unsure whether this is a requirement or good practice. Thanks.

Are you qualified for EICR's?

Regards
 22 April 2013 10:55 AM
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jsa986

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510.3 Every item of equipment shall be selected and erected so as to allow compliance with the regulations stated in this chapter and the relevant regulations in other parts of BS 7671 and shall take account of manufacturers' instructions."

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 22 April 2013 11:02 AM
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Bluesmeister

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We are also fitting 3A fused connection units as per the manufacturer instructions.

Very often we will wire the bathroom lighting circuit via a 3A fused spur for this very reason.
 22 April 2013 11:25 AM
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OMS

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Does the big switch thingy on that large white box thingy near the meter thingy have any purpose?

Regards

OMS

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 22 April 2013 11:44 AM
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rocknroll

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And now the science for you and how you apply the science is up to you, a few years ago now at Cambridge we looked into the case of bathroom type fans catching fire and found it only generally occurs during the locked rotor scenario, fan blades off centre, dust, insulation, toilet paper etc; locking the fan, once the temperature of the windings got to around 350F (180C) the windings insulation caught fire, since then a thermal fuse is required to be fitted, it operates at around 250F (120C) well before the windings insulation can overheat to the level it will ignite, sometimes this is visible but in these days of miniaturisation is incorporated in the windings.

What was also observed was the 3A BS1362 fuse did not operate 90% of the time but the protecting 6A and 10A MCB did.

Just information as this does not supersede good practice guides or manufacturers instructions.

regards

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Edited: 22 April 2013 at 11:51 AM by rocknroll
 22 April 2013 11:48 AM
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Parsley

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What reg states that a local isolator must be fitted?

I think you need to have a good look at section 537.

Regards
 22 April 2013 12:09 PM
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Grumpy

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Thank you all, most informative. Particularly Jaymack.
 22 April 2013 12:35 PM
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ebee

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Jaymark,
I think Grumpy just smacked yer botty!

"the big switch thingy on that large white box thingy near the meter thingy" it is also a means of isolating all lighting circuits inside a back box containing more than one circuit (Ground floor & 1st floor lighting for example).

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Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 22 April 2013 12:53 PM
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JZN

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Well grumpy, there seems to be no difinitive! Section 537 is obviously aimed mostly at chunky dangerous stuff like lathes and as you suspect (and OMS bluntly points out!) for a domestic fan the MCB will do just fine.

I always put an isolator in if the fan has timer over run simply for the convenience of the householder so that they don't have to have the fan on with the light if that's what they want.

A bit harsh Jaymac. Anyone doing an EICR can't really be expected to know what the manufacturers instructions for installation might be for each bit of fixed equipment encountered, although all domestic fans seem to have the bit about 3amp fuses in the instructions.

I have to admit i rarely bother to fit one and rely on the MCB.

John
 22 April 2013 12:59 PM
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ebee

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He did not say that he actually did the EICR , he said he was prompted by (seeing perhaps) one to ask the question.

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Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 13 May 2013 10:24 PM
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antric2

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A form of local and visible isolation is needed on fans for a few reasons but the most practical reason is if the fan is in a bathroom or understair area with no windows then the fan can be isolated to replace whilst still allowing the light to be on.
Regards
Antric
 14 May 2013 05:24 AM
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ebee

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In the absence of any particular instructions I`d say a fan with timed overun does require its own isolator.
If it caught fire, got wet, needed replacing you should not be going to that big switch thingy on the big box thingy to make it safe.
If it`s purely switched with the light or on its own then its not as important.

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Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 14 May 2013 05:55 PM
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leckie

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I think that in a previous thread the general thought was that if it was decided the isolator was for mechanical maintenance, eg cleaning, that an isolator should be fitted that was under the control of. The person carrying out the maintenance. This could be an isolator adjacent to the fan or a lockable type outside of the room.

I'm not sure if manufacturers ask that an isolator is fitted, if they do the. You would have to fit one in any case. To me it's common sense to fit an isolator to a timer fan that can isolate the fan independent of the light. There's that common sense again!
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