Light switches wired wrongly

[81011]

We've got a newish house and some of the light switches are the wrong way round (the switch is in the on position when light if off and vice versa).
I haven't unscrewed the switch/plate to look inside it yet, before I do so I was wondering what to expect?
It's happenend in several places around the house, sometimes where there are 2 switches around the room in question where the light is off but one switch is on the on position and the other in the off position. Plus there's also one room where there's a 3 lights all able to be turned on/off individually, via one switch plate that has 3 switches/buttons on it, when all lights are off, 2 switches are in off position and 1 is in the on position.
Not the end of the world but is does drive me a little mad!
Thanks in advance for any advice

 

[Murdochcat]

What you describe is VERY normal for 2, 4 or 4 way switching. There is no on /off really - so don't bother about it

If the switches are simple on / off then its an easy fix

 

[blup]

If you are sure a particular switch is one way, just flip it.

 

[ericmark]

Switches often marked com, S1, S2, swapping the S1 and S2 will swap if up or down for off. However which is correct? Most homes down is on, but most industrial premises, down is off, so if anything falls on the switch, it will switch it off not on.

Since 13 amp sockets down is on, I tend to do the same with lights, but as to which is correct, that is another story. Reasonably sure any fireman's isolator has to be down for off.

 

[Harry Bloomfield]

Two-way switches, I try to ensure that if both switches are up, the light is off. That means with all switches up, all lights are turned off, irrespective of type of switch.

If there are two switches in one plate, both two-way switches, but one used as a one-way - but working the wrong way, then simply move the wire in the switch used as a one way, from L1 to L2, or L2 to L1, to reverse the operation. Single gang one way switches, can simply be corrected, by removing the screws, and turning the entire switch upside down.

 

[sparkwright]

To save confusion, if you tell us the markings in the switch (they do vary) we can tell you straight away which connections to swap over.

 

[81011]

Two-way switches, I try to ensure that if both switches are up, the light is off. That means with all switches up, all lights are turned off, irrespective of type of switch.

If there are two switches in one plate, both two-way switches, but one used as a one-way - but working the wrong way, then simply move the wire in the switch used as a one way, from L1 to L2, or L2 to L1, to reverse the operation. Single gang one way switches, can simply be corrected, by removing the screws, and turning the entire switch upside down.

Thanks for all your help, I have (as above) moved the wires from L1 to L2 and from L2 to L1 and that has corrected it - delighted! Two mre switches to do at some point.....thanks again (now on to the LED problem with the spotlights in the en-suite!)

 

[plugwash]

Switches often marked com, S1, S2, swapping the S1 and S2 will swap if up or down for off. However which is correct?

I generally understood that "down is on" is the traditional british convention, while "down is off" is the IEC convention. As switchgear has been harmonised, but wiring accessories have not this leads to practically all british premises having a mixture of the two conventions.

 

[ebee]

Notably - our consumer unit mainswitches used to be the opposite sense of what they are today, installations with both types are not unknown, so care needed more than just a quick glance.
The change over did confuse a few folks at the time I knew of one fellah who opened up the mainswitch on a brand new consumer unit at the time in order to "correct the error" and ended up needing a new mainswitch or consumer unit, it was the Wylex Red Rocker meant as a warning of "upsidedowness"

 

[Harry Bloomfield]

Notably - our consumer unit mainswitches used to be the opposite sense of what they are today, installations with both types are not unknown, so care needed more than just a quick glance.

The old, pre-war, cast-iron switch fuses, (Prentice?)which included one or two rewirable fuses, had to have the switch/cover interlock handle down for off. The old, though much later MEM pressed steel switch fuse, needed the handle rotated from vertical, to horizontal, to isolate before the lid could be opened.

 

[SUNRAY]

The old, pre-war, cast-iron switch fuses, (Prentice?)which included one or two rewirable fuses, had to have the switch/cover interlock handle down for off...

Ah yes but confusingly the red firemans switch which looked identical apart from the shape of the handle was up-off.

 

[ebee]

yes it was all a confusion. Plus the convention for one way switches was kept but , of course, could not apply to two or more way switching.

I suppose it was the same as for water taps hot tap v cold tap, a convention to some extent for many years then more recent ways more of a convention as to which was on the left or right hand side.

At least we kept to the convention of which side of the road to drive, I remember either Norway or Sweden changing, everybody got up on a Sunday morning and the police were out in droves ensuring everybody remembered the change, I think it was the 60s when less vehicles about, nowadays it would be more of a calamity than it was back then.
It would make more sense if everyone drove on the proper side of the road like what we does, supposedly being fixed upon by knights jousting and being predominantly right handed.
I heard two supposed reasons for the switch up/down change though 1/ something dropping down on the switch and the possibility of accidental switching and 2/ easier to reach out and flick down in haste.
I suppose most countries having right hand threads as the prime normal choice has origins too?
The water taps thingy I`ve heard suggested it was for people with poor sight so I imagine the standard was to follow what the majority, if any, already had?

How tall is a British Standards person and how does it compare with a European Standard person or a World wide person?

Makes yer think dunnit?

 

[Harry Bloomfield]

Ah yes but confusingly the red firemans switch which looked identical apart from the shape of the handle was up-off.

Usually outdoors, provided for high voltage discharge advert lights, and maybe petrol pumps.

 

[bernardgreen]

red firemans switch which looked identical apart from the shape of the handle was up-off.

which enabled it to be turned off by anything that could push the lever upwards. If it had to be pulled down to switch off then a rod with a hook would be needed,

 

[SUNRAY]

which enabled it to be turned off by anything that could push the lever upwards. If it had to be pulled down to switch off then a rod with a hook would be needed,

The most common explanation I've heard has been by a policeman of minimum required height with his tickling stick.