PIR sensor triggered by boiler steam plume....
JimK
new boiler exhaust sited under a well-positioned PIR for (seperate,
distantly mounted) outside lights.
When the boiler's burning and outside light level is low (i.e. all
winter!) the steam plume/exhaust triggers the PIR and all the outside
lights come on like a f-in Xmas tree....
Now that particular PIR sensor's wiring goes through the boiler room/
area -
What would it take to dream up some sort of "interlock" to temporarily
switch off/disable that PIR when the boiler is firing...or is moving
the PIR from it's favoured location the only way?
NB there is another PIR on the same circuit and having that and the
lights still operational would be preferred
TIA
cheers
JimK
Harry Bloomfield
> What would it take to dream up some sort of "interlock" to temporarily
> switch off/disable that PIR when the boiler is firing...or is moving
> the PIR from it's favoured location the only way?
That would not be too difficult to accomplish, but it would not really
help....
Most PIR's when they are first powered up, will turn the light on until
they have settled back down.
The easy way, if it can be done is to mask the sensor with a bit of
black tape so it can't 'see' the plume.
--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk
JimK
I suspect that masking it enough to escape the plume would mean it may
as well be removed, it's above and looking down and partially across
the plume....
Is there any way to interrupt the switched live (or equiv) of the PIR
when the boiler is firing - so whilst PIR still powered up (and so
avoiding the startup prob) it's "false" triggers would not actually
switch any lights on?
Ta
JimK
Owain
> Is there any way to interrupt the switched live (or equiv) of the PIR
> when the boiler is firing - so whilst PIR still powered up (and so
> avoiding the startup prob) it's "false" triggers would not actually
> switch any lights on?
Yes. Wire the coil of a relay to the 'call for heat' terminal of the
boiler, and its contacts to interrupt the PIR output.
Owain
Scott M
> ..... well-positioned ......
Obviously not!
Moving it is the best long term solution - Owain's solution will work
but what's the use of a PIR that only works half the time?...
--
Scott
Where are we going and why am I in this handbasket?
JimK
my boiler's not on half the night - off by 9pm plus I'm a yorkshireman
- where TF do you live then?
Can we presume the Northern Lights illuminate your drive?
Cheers
JimK
JimK
ah sounds promising - can you point me to a likely looking relay
somewhere please and any tips/notes on installation would be
gratefully appreciated.
cheers
JimK
Calvin Sambrook
news:6c38edc4-dc7d-484b...@l35g2000vba.googlegroups.com...
At an electrical level Owain is right but I think you might hit problems
with the PIR detecting the residual hot air movement after the boiler has
finished firing. Remember that the PIR detects Infra Red pattern changes
and to it the hot air from your boiler will look like movement.
Lot of places sell lots of suitable relays. Maplin are good for one-off DIY
stuff. Look for a relay which plugs into a base just in case you ever need
to replace it. You need a 230V coil SPST (single pole, single throw) with
contacts rated plenty high enough for your lamp. Ideally 5A contacts would
be nice as they would then be protected by the lighting circuit protection.
I'd also buy a box to put it in and personally I'd mount it all on a bit of
stripboard (vero) along with some screw terminals.
If you do use vero you need to remove every second strip of copper by
heating it and peeling it away as the inter-copper gap isn't really spec'd
for mains.
Consider also that your boiler circuit and your light circuit really should
be kept separate, including the N.
js.b1
it in a DIN enclosure.
From the OP questions, playing around with veroboard & mains could get
"interesting" :-)
Far simpler to move the PIR, or put the PIR on a local/spur/CU-DIN-
rail timer, or fit a time-limited dusk-to-dawn photocell switch with
fluorescent lighting in place of what sounds like 150-300-500W halogen
"christmas tree".
The police supposedly say a photocell light is more effective than
PIR, depends on your neighbours re whether a constant low level night
light would make them moan... the extra's for the original Dawn Of The
Dead around here.
Our neighbour blamed me for fitting interior wall lights which shone
into her bedroom. Her bedroom is around the side; the wall light is
far above the window so creates a 60W light-fall which goes downwards
obstructed by a roller blind & obscured glass; her hall window is 9ft
above ours and 20ft away so way above the light-fall path; the
interior wall light is original and about 57yrs old; the sodium street
light outside her driveway on the other hand... (sigh :-)
JimK
> Look on Ebay for a contactor, eg, Square-D 25A 2-pole £5. Then stick
> it in a DIN enclosure.
> From the OP questions, playing around with veroboard & mains could get
> "interesting" :-)
indeed :>)) vero board etc would involve lots more guidance from you
guys :>)
as it is you'll have to hold my hand a bit on the practical aspects of
contactor - I am confident with domestic wiring circuits, principles,
practices etc but this is a (interesting) new avenue to me...
e.g. how do i interrupt the PIR switched live output with a normally
open contactor?
> Far simpler to move the PIR, or put the PIR on a local/spur/CU-DIN-
> rail timer, or fit a time-limited dusk-to-dawn photocell switch with
> fluorescent lighting in place of what sounds like 150-300-500W halogen
> "christmas tree".
>
nah don't fancy the "on all night" thing, if they are gonna have a go
they can bring their own torch (and trigger the xmas tree! as long as
the boiler's not on where that PIR is (etc...))
thanks
JimK
Dave Osborne
Nine O'Clock or not, it gets dark in Yorkshire at 4.00p.m. in the middle
of winter. If your heating system is designed, set-up and maintained for
maximum efficiency, then it should be running with "long-burns", which
means that, as Scott quite rightly pointed out, your PIR will regularly
be out of action for minutes at a time over a period of up to five hours
a night (and that's not allowing for a similar situation in the early
morning if your boiler comes on before it gets light).
I would have thought that re-thinking the location of your PIR is a much
more sensible option. In fact, the first thing I would do is replace the
PIR - I wouldn't actually expect it to go off under these circumstances.
TLC Direct have a wide choice of Mains PIRs:
Calvin Sambrook
On Oct 24, 12:17 am, "js.b1" <js...@ntlworld.com> wrote:
>> Look on Ebay for a contactor, eg, Square-D 25A 2-pole �5. Then stick
>> it in a DIN enclosure.
>> From the OP questions, playing around with veroboard & mains could get
>> "interesting" :-)
>indeed :>)) vero board etc would involve lots more guidance from you
>guys :>)
>as it is you'll have to hold my hand a bit on the practical aspects of
>contactor - I am confident with domestic wiring circuits, principles,
>practices etc but this is a (interesting) new avenue to me...
>e.g. how do i interrupt the PIR switched live output with a normally
>open contactor?
Well the first practical aspect is that you need a normally closed contactor
("contactor" is really just another name for relay) not a normally open one.
You probably already know this but I'll cover it anyway...
A contractor or relay is a switch which is turned on or off by a control
current through it's coil. You're going to use a switch which is a simple
single-pole (ie. one circuit), single-throw (ie. it just opens and closes),
this is abbreviated to SPST. The control coil will be 230V and when a relay
is controlled by 230V it often gets called a contactor.
You need to take a LN pair of wires from your boiler "calling for heat"
input, (that is the switched live wire which goes live when the boiler is
being told to fire up and an associated N) and connect these to the coil of
the contactor. The "normally closed" bit in the contactor description says
that the switch side of it is closed when the coil is de-energised and open
when there's current through the coil so when the boiler is being told to
fire up the switch will be open and your lights will be off and when the
boiler is turned off there won't be any current through the coil so the
switch will be closed.
You need to cut (break into) the switched live (only) between the PIR and
the light and connect the cut ends to the switch outputs of the contactor.
You need to break the output from the PIR rather than the input to it
because of the tendency of PIRs to switch on when first powered up.
That's it really, easy. In fact the hardest bit will probably be the
physical arrangements for getting the wires to the right place. If you
can't find a suitable NC contactor it's perfectly possible to use a SPDT
(the D means double or dual), also called a "changeover", and only wire to
two of the three switch terminals. If you do that the switched live from
the PIR goes to one of the output terminals and the wire to the light goes
to the common - it's a tiny bit safer that way.
Scott M
> my boiler's not on half the night - off by 9pm plus I'm a yorkshireman
> - where TF do you live then?
Soz, should have put a smiley on the first bit. South coast and also, no
heat after 9pm, but as Dave says it's dark from 4pm by the solstice.
Scott M
> In fact, the first thing I would do is replace the
> PIR - I wouldn't actually expect it to go off under these circumstances.
I've got one on the drive that detects the warm body of a car engine
arriving and then, if you wait for the light to go off again, will be
triggered by the warm air let out by opening the door.
js.b1
with new cable run to it.
If the cable is run on an outside wall use TLC FP200 (white) or HO5/
H07 rubber cable of 1.0mm (black).
If the cable enters from the rear, use a IPx4 rated junction box,
gland & run cable to the new position.
Disabling the PIR for a time is just pointless.
Relocate it as necessary, simple maintenance in view of spurious
performance due to unexpected interaction with boiler exhaust plume,
write out your own MWC.
Dave Osborne
> Dave Osborne wrote:
>
>> In fact, the first thing I would do is replace the PIR - I wouldn't
>> actually expect it to go off under these circumstances.
>
> I've got one on the drive that detects the warm body of a car engine
> arriving and then, if you wait for the light to go off again, will be
> triggered by the warm air let out by opening the door.
>
Ours comes on by the heat of the car engine as well as it happens.
I would, none the less, and depending on how much of a pain it would be
to re-do the cables, be thinking about replacing the PIR in-situ and if
that doesn't cure it, then move the existing/new PIR so it is not
affected by the boiler.
JimK
> JimK wrote:
> > On Oct 23, 7:42 pm, Scott M <no_one@no_where.net> wrote:
> >> JimK wrote:
> >>> ..... well-positioned ......
> >> Obviously not!
>
> >> Moving it is the best long term solution - Owain's solution will work
> >> but what's the use of a PIR that only works half the time?...
>
> >> --
> >> Scott
>
> >> Where are we going and why am I in this handbasket?
>
> > my boiler's not on half the night - off by 9pm plus I'm a yorkshireman
> > - where TF do you live then?
>
> > Can we presume the Northern Lights illuminate your drive?
>
> > Cheers
> > JimK
>
> Nine O'Clock or not, it gets dark in Yorkshire at 4.00p.m. in the middle
> of winter. If your heating system is designed, set-up and maintained for
> maximum efficiency, then it should be running with "long-burns", which
> means that, as Scott quite rightly pointed out, your PIR will regularly
> be out of action for minutes at a time over a period of up to five hours
> a night (and that's not allowing for a similar situation in the early
> morning if your boiler comes on before it gets light).
you assume the boiler is on from 4pm and that it's the only heat
source....
remember there is more than PIR...
> I would have thought that re-thinking the location of your PIR is a much
> more sensible option. In fact, the first thing I would do is replace the
> PIR - I wouldn't actually expect it to go off under these circumstances.
but until I explore the other options courtesy of this NG and it's
contributors I won't be able to decide will I?
PIRs not responding to steam and exhaust fumes from a boiler - how's
that work then?
JimK
JimK
> Since OP lacks the electrical skills, refit the PIR in a new position
> with new cable run to it.
NB:- OP more than happy to expand knowledge based on that profered -
hence query in 1st place :>))