House alarm into light fuse

[Mottie]

What’s a CFL?

 

[Hot&Cold]

What’s a CFL?

Compact Fluorescent Light Bulbs

 

[paulramplin]

Incidentally, to the OP - your alarm probably shouldn't have gone off due to a mains failure. What's likely happened is that the backup battery in the panel needs replacing, so when you lost mains power, the panel lost power totally, which resulted in the bell box alarming using the power from it's own battery. You probably want to look into checking/replacing the backup battery in the alarm panel to prevent the alarm doing this in future power cuts.

This sounds like what might have happened - I will check the battery in the alarm control panel.
Thanks.

 

[securespark]

Historically, alarm installers put the supply to the panel on the lighting circuit because if the supply did fail it would be noticed very quickly and acted on (as the lighting would have gone out).

 

[ban-all-sheds]

I had to ponder that for a while. I eventually concluded that BAS was probably referring to the 'old' method of arranging 2-way switching, which results in 'unpaired' L and N conductors - and this might facilitate induced voltages/currents high enough to cause at least flickering in CFLs or LEDs when they are 'switched off' ...

... or maybe he was thinking of something totally different!

No - that is what I was thinking.

I was also thinking (after the event, while out yesterday) that I should have been more explicit in my post.

Beware of dimmer switches and some methods of 2-way switching - CFLs may not be suitable.

Dimmers (and other electronic switches) may not work with CFLs. The CFL itself may not be suitable for dimming, even if it says it is it may not like your particular dimmer, or vice-versa, and some electronic switches (e.g. touch sensitive, remote controlled, timer) may expect a conventional incandescent lamp in order to provide a current path for the electronics in the switch even when off.

And as JW2 says, some methods of 2-way switching will cause CFLs to flash regularly when off.

 

[jg321]

Dimmers (and other electronic switches) may not work with CFLs.

And to add - If CFLs which aren't designed for dimming are dimmed, they tend to give off huge amounts of RF interference, which can and, at least for me, did, wipe out broadband.

It was particularly difficult to diagnose at first, as the lamp in question was in one of those external light fittings that was off during the day, came on dim all night, but went bright when the PIR detected motion. That said, as soon as I went outside with an AM radio, it went nuts, and stopped going nuts as soon as I activated next doors light (which was around 15 feet below our telephone drop cable). The radio then went nuts again as soon as I stopped moving, and the light dimmed.

Edit to add: The word dimmed has lost all meaning to me, after reading it so many times!