Indicator modules: Scolmore

[ToughButterCup]

Look, I'll come clean: this is an embarrasing question to have to ask. I have a done quite a bit of research - and I read the words on the pages, but my head sees fog.

 

I love the idea of Indicator Switches. They tell eejits like me that - when lit - something is happening. Current is flowing. Situation normal, everybody's happy. And I just luuuuurvvvv the Scolmore range of indicators (others are available I'll bet - but you need to ask @Onoff, @JSHarris, or @ProDave).

 

What about a more useful type of indicator switch, eh? 

What about one which lights up when something FAILS ? Like (say) the MVHR is drunk and refusing to fight. Or the freezer's refusing to freeze. I suppose what I really mean is when those things don't have electricity for some reason ... like when their RCBO has tripped.

 

What I'd like is a simple visual warning that all's not well. Is there an indicator light for that type of thing?

Or maybe you can wire any indicator light to illuminate when the circuit it protects (?)  fails?

Wish I'd paid more attention in Physics lessons.?

[SteamyTea]

Um.

https://drivetribe.com/p/germans-make-mistake-fZl0jxc0RKOLdx1lTTvl0Q?iid=B4R_m5lVQ1-Nf8GCJBd4cg

[andyscotland]

There are various things on the market as power failure indicators or power failure alarms.

 

For example for a freezer you would potentially want something quite attention grabbing rather than just a wee light in the corner. Also for a freezer you might want to consider something more like a temperature alarm, for the situation where it's getting/drawing power but not actually cooling anything down.

 

Obviously a power-off indicator would ideally have a battery backup, otherwise it wouldn't be guaranteed to light when there's no power. The circuitry is pretty simple, but I suspect probably too big to fit neatly on a standard one-way switch if you're envisaging something that would be identical to a "normal" indicator switch but with the neon indicator function reversed.

[ToughButterCup]

Ah, Andy, now I know what to search for.... thanks,

ian

[Jeremy Harris]

Failure indication is an art all to itself.  There are several general rules pertaining to how failures should be indicated, the most common being that things should fail safe, and that means either switching off and waiting to be noticed, providing some sort of alert that something has gone awry, but doesn't require immediate attention, to something has gone awry and you need act immediately.

 

In a domestic environment there aren't many failure modes that fall into the "you have to do something immediately" category.  Fire alarms, and possibly flood alarms, are probably the only two that I can think of.  A freezer failure is a lower category, as there is no need for immediate action if a freezer fails, there's usually an hour or two of leeway.  Many MVHR systems have their own alarm/alert systems.  Our's has an alert when the filter needs changing, but doesn't have an alert in the power fails, other than the display on the wall turning off (which is probably as good as anything).  Some stuff is self-indicating mechanically, like MCB, RCBs and RCBOs - a glance at the panel shows if any have tripped (but not why, in the case of RCBOs). 

 

The problem with using indicator lights to show when something has failed is that the indicator lights themselves maybe as prone to failure as whatever they are indicating the status of.  The best example I can think of are things like the caution and advisory panel lights on an aircraft.  These light up a caption, and may also make a sound, whenever something goes out of limits or fails.  The way the risk of the C & A lights themselves failing is mitigated is by having a push-to-test button that is exercised as a part of the pre-flight checks, and which illuminates all the C & A indicators.  A more fail-safe indicator is the dolls eye used to show that oxygen is flowing  to a mask.  This device is spring loaded to the eye is closed with no flow, and only opens when there is flow.  If there is a leak in the mask etc, then the eye opens all the time, if all is well the eye opens and closes with each breath.

 

I'm inclined to think that a house really needs a range of different alert and alarm systems, each specific to the system.  As above, temperature drop beyond a normal limit would be a sensible one for a fridge or freezer.  Absence of airflow might be a good option for MVHR.  Fire alarms need to work on a change of condition that is a fairly reliable indicator of fire, without giving false alarms, so rate of change of temperature is a good option for a kitchen, whereas a smoke detector is a better option for a hallway or landing.

 

Finally. there's always the option of installing a home automation system and have that report the state of everything back to some device, or incorporate algorithms to do useful things, like turn off unused lights after a certain period of time, perhaps using occupancy sensing to determine when lighting is no longer needed.

[ToughButterCup]

47 minutes ago, SteamyTea said:

Um.

https://drivetribe.com/p/germans-make-mistake-fZl0jxc0RKOLdx1lTTvl0Q?iid=B4R_m5lVQ1-Nf8GCJBd4cg

 

Quote

The Germans are right.

https://drivetribe.com/p/germans-make-mistake-fZl0jxc0RKOLdx1lTTvl0Q?iid=cxMMTyyfQAKsc7wk_OXOMQ

[SteamyTea]

Erwin Schrödinger's Switch, it is both On and Off.

Or should that be @Onoff's Bathroom. It is both finished and unfinished.