3 switches controling 1 light circuit question

[Lower]

Can anyone help me by pointing me in the right direction for a wiring diagram of this sort of circuit?

I have two lights on the same circuit controlled by 3 switches. One of the switches is a 2 way dimmer, the others are standard two way switches.

I have an issue with the lights flickering and not achieving full brightness which i think is down to the particular way the switches are set at the time though i've not yet managed to work out what how they have to be set to cause the problem. Its not the dimmer itself as i've replaced the original dimmer (with which we had the same problem) with a new one.

All the connections seem to be ok, so i'm assuming that the circuit is wrong or the dimmer isn't suitable for this application.

Any advice or help appreciated.

 

[ban-all-sheds]

Can anyone help me by pointing me in the right direction for a wiring diagram of this sort of circuit?

//www.diynot.com/wiki/electrics:intermediate

I have an issue with the lights flickering and not achieving full brightness which i think is down to the particular way the switches are set at the time though i've not yet managed to work out what how they have to be set to cause the problem. Its not the dimmer itself as i've replaced the original dimmer (with which we had the same problem) with a new one.

The only wiring problem that could be to blame would be a dodgy connection somewhere. Have you checked everything on the circuit for tightness, not just those lights and switches? What happens if you replace the dimmer with a switch?

Or.. - the lights aren't in series, surely? Just how dim are they?

All the connections seem to be ok, so i'm assuming that the circuit is wrong or the dimmer isn't suitable for this application.

What sort of bulbs are they?

 

[OwainDIYer]

I have two lights on the same circuit controlled by 3 switches. One of the switches is a 2 way dimmer, the others are standard two way switches.

That'll be your problem then.

You need a 2-way dimmer, an intermediate switch, and a 2-way switch.

AFAIK you can't get intermediate dimmers.

 

[Lower]

Thanks for link. Exactly what i was looking for.

I've checked every connection that i can find. Specifically all the switches, all the connections at the lights themselves and the junction boxes under the floorboards. All were well made connections with no obvious faults or obvious bodges.

They're definitely not in series as removing one bulb doesn't stop the other one from working.

The flicker occurs when a standard incandescent bulb is fitted and the bulb appears to give out approximately half its normal light.

I've currently fitted energy saving bulbs (which obviously don't work with the dimmer) because they don't seem to suffer from the flicker.

 

[Lower]

I have two lights on the same circuit controlled by 3 switches. One of the switches is a 2 way dimmer, the others are standard two way switches.

That'll be your problem then.

You need a 2-way dimmer, an intermediate switch, and a 2-way switch.

AFAIK you can't get intermediate dimmers.

I didn't know an intermediate switch existed. I can't remember how many wires there were going into the landing switch. I will check that as soon as i get home tonight.

 

[sparkwright]

Try and send photos of everything.

 

[AdrianUK]

Why not try replacing the dimmer switch with a conventional two-way switch?

If all comes good, then its a dimmer problem, if its still not right then you have eliminated one variable from the equation. Your next step would then be to reduce the circuit to a simple 1 way switch, thus elimintaing the travellers & intermediate switch & see what happens.

Adrian

 

[Lower]

I am now even more confused.

The circuit appears to be wired correctly with an intermediate switch.

However, i initially had an energy saving bulb in it because it didn't seem to suffer from the flicker. After a day or so's use, when the light was turned on at the dimmer (full power, not dimmed) there was a pop type noise from the energy saving bulb and the breaker in the consumer unit tripped.

I therefore assumed that the bulb had failed and replaced it with a dimmable halogen.

All worked fine. No flicker, light dimmed normally, and would switch from all switches.

A day or so later all seems to work fine except that the dimmer no longer works as a dimmer. You can turn the lights on and off with it, but you can't dim the lights. I've tried all the combinations of switches but that seems to have no effect.

I can only conclude that the dimmer itself has failed.

But i still haven't got to the cause of the flicker which was there when the previous dimmer was fitted as well.

Next step is to replace the dimmer with a standard two way switch and see whether the flicker is still present.

 

[ban-all-sheds]

The low energy lamp and the dimmer probably failed for the same reason - they aren't compatible with each other.

 

[Lower]

The low energy lamp and the dimmer probably failed for the same reason - they aren't compatible with each other.

That's my assumption. I knew that the low energy lamp wasn't dimmable and weren't supposed to be used together, but the low energy lamp seemed to be able to deal with the flicker. I need to get some light in the hall for the decorator who was working in there at the time.

However, it obviously wasn't a long term solution!

Just for clarity's sake, the flicker was present before the low energy bulb was temporally fitted.

 

[ericmark]

Bulbs are made with a coiled coil element which means although they should be a resistive load there is some capacitive and inductive component. The dimmer unit will be affected by the capacitive and inductive components of the bulbs. In the main it is minimal and they work OK. But some times the frequency of the combined system becomes critical and produces some odd effects. Normally changing bulbs will cure this.

Discharge lamps and LED lamps can be dimmed but it often requires special dimmers and control gear and in the main the electronics used with compact florescent units will not allow dimming.

In warm countries where discharge lamps have been used for years as unlike the UK the heat produced with the lamp is not wanted have adopted a different method to adjust lighting levels. The 1/3 and 2/3 split in switching the lamps is common giving 3 levels of light.

The discharge lamp in warm countries saves energy but not in the colder claimants as the warmth given off is wanted. So in cold countries one can't call discharge lamps energy saving unless being used in a non heated area.