I have an outside floodlight which is controlled by a PIR. It's fed from an
FCU spurred off a ring main. The light sometimes comes on for a few seconds
when other things on the same ring - e.g. Teasmaid (yes, ours is still going
strong after more than 30 years!) are switched on or off. I'm familiar with
PIRs coming on for a while when the mains is restored after an interruption,
but not to them being affected by *other* things going on or off. I assume
it's responding to some sort of noise (contact bounce etc.) being injected
into the mains. Has anyone else come across this?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored..
Messages sent to it may not be read for several weeks. PLEASE REPLY TO
NEWSGROUP!

No - I've got several PIR's and some of them run off a wall plug which
also has a kettle and toaster nearby and they dont set it off. Perhaps
your wiring is struggling to maintain a good voltage when things are
switching on and off so the PIR thinks it's being switched?

I wouldn't have thought it's noise.

On Mon, 17 Dec 2007 10:21:46 -0000, "Roger Mills"
wrote:

I assume
it's responding to some sort of noise (contact bounce etc.) being injected
into the mains. Has anyone else come across this?

Yes, it's very common. I've got one PIR controlling a front door
light that merrily came on whenever any coventional fluorescent light
in the house was turned on. Cured by fitting a noise filterin the feed
to the PIR.

"Roger Mills" wrote in message
...
I have an outside floodlight which is controlled by a PIR. It's fed from
an
FCU spurred off a ring main. The light sometimes comes on for a few
seconds
when other things on the same ring - e.g. Teasmaid (yes, ours is still
going
strong after more than 30 years!) are switched on or off. I'm familiar
with
PIRs coming on for a while when the mains is restored after an
interruption,
but not to them being affected by *other* things going on or off. I assume
it's responding to some sort of noise (contact bounce etc.) being injected
into the mains. Has anyone else come across this?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored..
Messages sent to it may not be read for several weeks. PLEASE REPLY TO
NEWSGROUP!



Did you install it? check for loose connections inside the lights housing
and any water getting into the housing, also the connection to the fuse?

Either that or it could be just coincidence ie spiders coming out from
behind for a daily workout. ;-)

In an earlier contribution to this discussion,
Peter Parry wrote:

On Mon, 17 Dec 2007 10:21:46 -0000, "Roger Mills"
wrote:

I assume
it's responding to some sort of noise (contact bounce etc.) being
injected into the mains. Has anyone else come across this?

Yes, it's very common. I've got one PIR controlling a front door
light that merrily came on whenever any coventional fluorescent light
in the house was turned on. Cured by fitting a noise filterin the feed
to the PIR.

Interesting! Is there a standard filter I can buy, and how does it need to
be connected - e.g. a capacitor across the mains, or across the PIR, or a
choke in series with the lamp feed, or maybe some combination thereof?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

In an earlier contribution to this discussion,
George wrote:


Did you install it? check for loose connections inside the lights
housing and any water getting into the housing, also the connection
to the fuse?

Either that or it could be just coincidence ie spiders coming out from
behind for a daily workout. ;-)

Yes, I did install it - so it's very unlikely that the connections are
loose. I think it's more than co-incidence, 'cos I can more or less make it
do it to order.

I think that Peter Parry is probably on the right lines with his suggestion
of a filter being needed.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

In article , Roger Mills
scribeth thus
In an earlier contribution to this discussion,
George wrote:


Did you install it? check for loose connections inside the lights
housing and any water getting into the housing, also the connection
to the fuse?

Either that or it could be just coincidence ie spiders coming out from
behind for a daily workout. ;-)

Yes, I did install it - so it's very unlikely that the connections are
loose. I think it's more than co-incidence, 'cos I can more or less make it
do it to order.

I think that Peter Parry is probably on the right lines with his suggestion
of a filter being needed.

Some of the earlier ones were very sensitive to radio energy and
interference, more recent ones are better in that respect!..
--
Tony Sayer

On Mon, 17 Dec 2007 13:45:06 -0000, "Roger Mills"
wrote:

Interesting! Is there a standard filter I can buy, and how does it need to
be connected - e.g. a capacitor across the mains, or across the PIR, or a
choke in series with the lamp feed, or maybe some combination thereof?

The one I used was made by Ferranti, weighed about 10lbs and came from
a Bloodhound missile system so may not be available in the shops. I'm
pretty sure I've got a box of much smaller plug in ones in the garage
in German (Shuko) plug/socket adapters but if you take them apart the
PCB's fit into a standard switch box. They wire in parallel with the
lamp, very simple, give me a ring or e-mail if you would like one.


--
Peter Parry | Hemel Hempstead | tel +44 (0)1442 212597 | fax
WPP Ltd | Herts, UK | +44 (0)973 269132 |+44 (0)1442-233169
http://www.wppltd.demon.co.uk/
Mobile communications and antennae.

"tony sayer" wrote in message
...
In article , Roger Mills
scribeth thus
In an earlier contribution to this discussion,
George wrote:


Did you install it? check for loose connections inside the lights
housing and any water getting into the housing, also the connection
to the fuse?

Either that or it could be just coincidence ie spiders coming out from
behind for a daily workout. ;-)

Yes, I did install it - so it's very unlikely that the connections are
loose. I think it's more than co-incidence, 'cos I can more or less make
it
do it to order.

I think that Peter Parry is probably on the right lines with his
suggestion
of a filter being needed.

Some of the earlier ones were very sensitive to radio energy and
interference, more recent ones are better in that respect!..


I once installed an alarm system with some cheap PIRs.
Radios in passing police cars and taxis would set it off
The Band III PMR transceiver in my vehicle would trigger
it when I was parked outside.
--
Graham

%Profound_observation%