Need alternate way to wire 2-Way and Off switch

[kez1]

Shown is a lighting circuit with :

• Hall lights
  
  
• PIR
  
  
• MK 20A SP 2 WAY & OFF switch (K4899 WHI)

The three possible switch positions are :

• The switch when pressed to the UP position activates the PIR (hot wire connected to PIR).
  
  
• The switch when pressed to the MIDDLE position de-activates everything completely (hot wire connected to nothing).
  
  
• The switch when pressed to the DOWN position activates the lights for permanent ON (hot wire connected directly to lights).

However the above arrangement is different to the convention that everyone knows with the simple ON / OFF lights switch which is press UP for OFF and DOWN for ON.


Can anyone advise how I can connect this 2 WAY & OFF switch so that UP is OFF, DOWN is ON and MIDDLE is PIR activated ?
(I wish to do this so it is close in line with the convention that everyone knows and saves confusion in operation)

 

[Risteard]

It's just a 2-way switch with the centre position off, so that is how it is designed to work (and is also sensible).

 

[Taylortwocities]

That MK switch is centre OFF, So On/OFF/ON. There is no option to do EXACTLY what you want with that particular switch, unless you start designing a logic or relay switch.

Try Googling an Off/On/On switch and see where that gets you..

 

[ban-all-sheds]

You'd have to use a relay or contactor with N/C contacts - supply the PIR via those and supply the coil from terminal 1 of the switch. So switch up, coil energised N/C contacts open, PIR has no supply. Switch in the middle, coil disconnected, N/C contacts close, PIR receives supply.

 

[Risteard]

Indeed, but I really can't see the benefit. I think it would be more confusing. Just label the switch.

 

[bernardgreen]

Removing the Live supply to the PIR may not be a good idea as when the supply is connected to it for the lamp to be controlled by the PIR then the PIR may go through a power up sequence which puts the lamps on until the PIR has stabilised.

As said without a relay or other switching device you cannot achieve what you want with a single ON-OFF-ON switch

 

[riveralt]

You will also need a camera to capture the images of those poor people who will waving their hands like mad to get the PIR to operate.
I really am struggling to see the logic in what you are doing here, surely a standard two way switch would be easier, particularly since you
appear to have a PIR ghost............
//www.diynot.com/diy/threads/false-pir-switching.434522/
Even if you do insist on going down the PIR route then you only need an on/off switch. When On the PIR will activate on detection - and most PIR's have an over-ride facility to keep the light permanently on.

 

[OwainDIYer]

You can't, because the centre OFF position doesn't have an output terminal.

Instead of one switch, you could use two switches, one changing between DAY (off) and NIGHT (on), and the other changing between AUTO and CONTINUOUS.

Suitable assemblies are available ready made as Sink/Bath switches for immersion heaters.

 

[ban-all-sheds]

You can't.

Yes he can.

Whether he should or not may be open to debate, but not whether it can be done or not.

 

[securespark]

If you want better logic, ditch the 3 posi switch in favour of a twin accessory pattress on which you mount an on/off isolating switch of a suitable type on one side and a one gang one way switch on the other, which just shorts together the permanent feed and the switched feed. Up is AUTO (ie only works when daylight sensor kicks in, in other words off during the day) and down is permanently on.

This layout has more logic.

 

[bernardgreen]

It can also be achieved with a two plate with two two way switches.

But I cannot find the image I produced to show the circuit diagram

 

[ban-all-sheds]

If you want better logic, ditch the 3 posi switch in favour of a twin accessory pattress on which you mount an on/off isolating switch of a suitable type on one side and a one gang one way switch on the other, which just shorts together the permanent feed and the switched feed. Up is AUTO (ie only works when daylight sensor kicks in, in other words off during the day) and down is permanently on.

This layout has more logic.

He wants to be able to have 3 settings:

OFF
PIR
ON

Two switches is not more logical than one.

TBH I think the simplest way would be to eschew the "up must be off" convention which concerns the OP, and use the centre-off switch as it's designed to be used, so centre is off, and the other ways are PIR and permanently on. Maybe rotate the switch through 90° if he's really worried about up/down.

Or get a 3-position rotary switch.

But not 2 switches.

 

[JohnW2]

Two switches is not more logical than one.

Perhaps not, but it may be more readily understandable by many people ...

TBH I think the simplest way would be to eschew the "up must be off" convention which concerns the OP, and use the centre-off switch as it's designed to be used, so centre is off, and the other ways are PIR and permanently on. Maybe rotate the switch through 90° if he's really worried about up/down. ... Or get a 3-position rotary switch. ... But not 2 switches.

Many of the general public may not be familiar with 3-position switches, and hence may not even be aware of the third (middle) position - for them, two switches ('on/off' and 'auto(PIR)/manual on') may be more understandable.

Having said that, as has been pointed out, most PIRs these days have built-in ('on/off/on') 'permanently on' functionality, so, with one of those, the OP would only need a single simple on/off switch.

Kind Regards, John