For a mains bathroom fan in zone 2 / 3, where should the DP isolator
be located?

I have a redundant immersion heater supply running to my loft, via a
switched spur in the downstairs kitchen, If this spur is replaced with
a 3A fused switched FCU, would this location be acceptable? Fan will
be a humidistat type, hence no requirement to connect onto lighting,
remote pull cord etc.

thanks
DD

"dirt dibbler" wrote in message
ups.com...
For a mains bathroom fan in zone 2 / 3, where should the DP isolator
be located?

I have a redundant immersion heater supply running to my loft, via a
switched spur in the downstairs kitchen, If this spur is replaced with
a 3A fused switched FCU, would this location be acceptable? Fan will
be a humidistat type, hence no requirement to connect onto lighting,
remote pull cord etc.

thanks
DD


Sounds a bodge. A few points:
Is the fan only for humidity control? What about 'odours'?
Could you say that the switch was "in a readily accessible position" and
"identified by position or durable marking to indicate the equipment
controlled"? (Electrician's Guide to the Building regs, 4.3)
If this arrangement were in someone else's house and you had to maintain the
fan, would it be obvious how to isolate it?
Remember that part P applies - I doubt that a suitably qualified person
would be happy with the arrangement.

Phil

dirt dibbler wrote:
For a mains bathroom fan in zone 2 / 3, where should the DP isolator
be located?

In the bathroom in zone 3 (or beyond the zones), or just outside the
bathroom in an obvious place.

I have a redundant immersion heater supply running to my loft, via a
switched spur in the downstairs kitchen, If this spur is replaced with
a 3A fused switched FCU, would this location be acceptable?

IMO, no, even with appropriate labelling. In BS 7671 reg. 131-14-02
requires every motor circuit to have a readily accessible device for
switching off, and 462-01-02 says that every device for switching off
for mechanical maintenance must be suitably located in a readily
accessible position.

Anyone trying to find the switch should be able to do so easily, without
having to traipse through the house looking for it in non-obvious
places, and without having to rely on the knowledge of one particular
person.

Fan will be a humidistat type, hence no requirement to connect onto
lighting, remote pull cord etc.

I'd still feed it from the lighting circuit via a conventional 3-pole
fan isolator (with one pole unused). That gives a bog-standard
arrangement that any competent person would recognise and be able to
work on safely.

--
Andy

On 2007-08-06 15:53:09 +0100, Andy Wade said:

I'd still feed it from the lighting circuit via a conventional 3-pole
fan isolator (with one pole unused). That gives a bog-standard
arrangement that any competent person would recognise and be able to
work on safely.

*Bog* standard?

(anyway, moving right along)....

I am completing my cloakroom project, and the fan has been located to a
concealed position behind a vented panel - I didn't want the fan itself
to be on show.

The panel is removable for servicing the fan. I'm debating
whether to fit the fan isolating switch along with some other switches
and outlets that are in a cupboard below the panel, or to fit in next
to the fan in the void behind the panel.

Since the panel has to be removed to access the fan, it occurs to me
that it's reasonable to put the switch there, next to the fan.
Actually it simplifies wiring because I don't then need to run the six
singles for it in the conduit.

I can't see any regulatory objection for either method, but do you have
nay thoughts?

Andy Hall wrote:

*Bog* standard?
(anyway, moving right along)....

Moving along at a tangent, the OED is interesting on the origins of
"bog-standard" which it dates to 1968:

"Ordinary, basic, standard; without extra features or modification;
unexceptional or uninspired. Cf. BOX-STANDARD adj.

"[Origin uncertain; perh. an alteration of BOX-STANDARD adj. (although
this is first attested later), after BOG n.4

"Differing theories of the origin of bog-standard have been proposed,
but none proven. An immediate association with BOG n.1 seems unlikely on
semantic grounds. The most commonly held view is that the transition
from box to bog resulted from a mishearing or misunderstanding of
BOX-STANDARD n.

"Others have suggested a derivation bog-wheel, former Cambridge slang
for a bicycle, though ultimately also related to BOG n.4: see P. Beale
Conc. Dict. Slang (1989) 47/2, 48/1."

(Where BOG n.1 is the wet spongy ground meaning and BOG n.4 is the privy
meaning.)

Anyway, I digress...

The panel is removable for servicing the fan. I'm debating whether
to fit the fan isolating switch along with some other switches and
outlets that are in a cupboard below the panel, or to fit in next to the
fan in the void behind the panel.

Since the panel has to be removed to access the fan, it occurs to me
that it's reasonable to put the switch there, next to the fan.
Actually it simplifies wiring because I don't then need to run the six
singles for it in the conduit.

I can't see any regulatory objection for either method, but do you have
nay thoughts?

"Nay thoughts" ...? It's preferable I think to be able to isolate the
fan before attempting to remove the panel (if only because someone
removing it for the first time doesn't know what they're going to find
behind it). But will the switch be readily accessible if it's in the
cupboard? Difficult to say much more really, without knowledge of all
the details. There's no requirement for emergency switching, so both
ways ought to be acceptable under BS 7671 if competently executed.
Discreet labelling might help - or not, depending on the circumstances...

--
Andy

Andy Wade wrote:

Moving along at a tangent, the OED is interesting on the origins of
"bog-standard" which it dates to 1968:

"Ordinary, basic, standard; without extra features or modification;
unexceptional or uninspired. Cf. BOX-STANDARD adj.

"[Origin uncertain; perh. an alteration of BOX-STANDARD adj. (although
this is first attested later), after BOG n.4

cf. Ideal-Standard that well known bog maker.




Anyway, I digress...


--
djc

On 2007-08-07 22:10:36 +0100, Andy Wade said:

"Nay thoughts" ...? It's preferable I think to be able to isolate the
fan before attempting to remove the panel (if only because someone
removing it for the first time doesn't know what they're going to find
behind it). But will the switch be readily accessible if it's in the
cupboard? Difficult to say much more really, without knowledge of all
the details. There's no requirement for emergency switching, so both
ways ought to be acceptable under BS 7671 if competently executed.
Discreet labelling might help - or not, depending on the
circumstances...

Sorry. To be clearer.....


The fan itself is a Vent Axia standard cloakroom/bathroom fan which
used to be on the ceiling about a third of the way across. There
is now a cupboard at one end of the room (full width) with a space
above it sufficient to accommodate the fan. Rather than having the
fan on view, not that it's a large one, I prefer to have a vented panel
which I have made to fit the space above the cupboard while being flush
with the frame.
The fan has been moved such that it is now behind said panel and out of
sight while still providing normal ventilation.

For access, I can remove the panel (held with magnetic catches) and
then I see the fan in its original form - i.e. cover and no live parts
accessible until its cover is removed with a screwdriver. The
choice is to locate the isolating switch in the top space near the fan,
or in the cupboard below.