Lights will not switch off

[stevedo]

I have some outside lights that are controlled by a timer. This has been working fine since we started using them (wer'e new to the house) however, yesterday I noticed that they were on when the timer should have switched them off.

Adjacent to the timer is a switch with a cable (3 core and earth) running to the timer. Usually this switch would turn the lights off, overriding the timer, but this is now not the case and the lights are on all the time regardless

The ONLY way I can turn these lights off is to use the switch at the consumer unit.

Any ideas as to why this is happening all of a sudden. I suspect the timer is faulty in some way but I would still expect to be able to turn the lights off using the switch.

Just to be clear, I have not touched any wiring at all in the house which may have caused this to happen, honest.

Thanks in advance
Steve

 

[mapj1]

1)check the switch - it could simply have welded up if bulb blew badly, and or check the connectors to it

However, 3 core +earth is more than is needed for a simple 'cut the live' isolator, i'd only expect 2 business cores, 'live from timer' and 'live to lights' plus a protective earth that does very little if its a plastic switch and box, so it may be does more than you think. Best to draw it out - and assume nothing about choice of core colours and functions, it MAY be something really horrible like neutral switched, and now shorted to earth an equally insanitary arrangement. However, before damning it, have look at what is there.
M.

 

[stevedo]

Hi M

there was a blown bulb, I have now replaced that.

I also replaced the switch, just to see if that was the problem, no difference.

More information. The only things on the circuit are 3 60W outside lights and 2 fluorescent lights in the garage. Using the switch on the CU only turns off these devices. The lights in the garage function normally.

The switch for the outside lights and the timer are situated indoors. There is a cable with red, blue, yellow and earth running into the switch. The outer white sheath of this cable has been removed inside the switch and the yellow wire inside has been cut. The yellow side going into the switch is connected to common, and the side which exits the switch is connected to L1.

The cable continues from the switch to the timer. Inside the timer, the yellow wire is connected to connector 1, the earth to earth, blue to 4 and red to 5.

For information the timer is made by Smiths and is of the type that uses pins and an inner and outer ring to control when devices are turned on and off.

As I said previously, this worked fine until a couple of days ago. Other than a blown bulb, nothing else has happened or been done to this setup.

Yours
really confused.

PS I took a picture of what I have described above but could not figure out how to post it!

 

[breezer]

PS I took a picture of what I have described above but could not figure out how to post it!

would you believe the answer is in forum information

 

[stevedo]

Picture now here

Steve

 

[stevedo]

Anyone have any ideas on what the problem might be? Do you need any more detail?

Many Thanks
Steve

 

[ChrisRogers]

do you know where that cable goes to?

 

[stevedo]

unfortunately not. I've tried to trace them from the lights themselves and from the switch/timer without success.

 

[Paul_C]

It's clear from the photo that you have the live feed to the timer on the red, neutral on blue, and yellow is the switched return to the light, which has the extra switch inserted to provide your "Override OFF" function.

If neither this switch nor the one in the timer will turn off the light, then there must be a short elsewhere in the wiring. You'll have to try to find where the 3c+E runs. If this cable doesn't appear as as loop-thru at the light fixture, then there must be a junction box somewhere.

 

[kendor]

What is the current rating of the timeswitch? the switch contacts may have welded together due to insufficient current capacity when switching the flourescent fittings, the contacts should be rated at twice the current load when flourescents are connected due to the inductive load and the ability of such circuits to jump contact gaps when opening.

 

[Paul_C]

the switch contacts may have welded together due to insufficient current capacity

Even if that were the case, that wouldn't stop the the second switch in series from breaking the circuit.

That looks like the Smiths timer which is generally sold for immersion heaters, so contacts should be rated 15A or so anyway.

 

[kendor]

the switch contacts may have welded together due to insufficient current capacity

Even if that were the case, that wouldn't stop the the second switch in series from breaking the circuit.
That looks like the Smiths timer which is generally sold for immersion heaters, so contacts should be rated 15A or so anyway.

of course if the switch contacts were not also welded together

 

[stevedo]

What is the current rating of the timeswitch? the switch contacts may have welded together due to insufficient current capacity when switching the flourescent fittings, the contacts should be rated at twice the current load when flourescents are connected due to the inductive load and the ability of such circuits to jump contact gaps when opening.

The fluorescents are not controlled by the timer. They are in the garage and switched using normal wall mounted switches. The only reason for mentioning them is that they are on the same MCB in the CU.

 

[stevedo]

the switch contacts may have welded together due to insufficient current capacity

Even if that were the case, that wouldn't stop the the second switch in series from breaking the circuit.
That looks like the Smiths timer which is generally sold for immersion heaters, so contacts should be rated 15A or so anyway.

of course if the switch contacts were not also welded together

I don't think the switch contacts are welded together. I replaced the switch and the problem is the same.

 

[kendor]

ok useful bit of info given so it's just the 3 x 60 w incandescent lamps then on the timer?