LED Bulbs won't work together on same circuit.

[FatAlan]

60W sounds high for an LED. Is it 60w equivalent?
Have you tested both bulbs else where? Could it be that just one is defective.

 

[Fullerbull]

Nope! I can put either one in either holder. The only criterion for them to work is that one of them must be filament. I know that this is an intractable problem and I have given it a lot of thought though I am not a Sparky (I was an engineer in a previous life). I think what I'll do is wait until I have my extension done in a few months time and get the electrician who does the wiring to check it all out and maybe re-wire. I suspect that ultimately we'll get it to work, but I'll probably never know the reason! If I do, then I'll post it. Thanks to all who have responded - I appreciate your time and thoughts.

 

[FatAlan]

LED is definitely a 240v? They're not connected in series are they and that is playing silly buggers with the LED?

 

[Fullerbull]

Sorry to the last two responders. I posted before I had seen your queries. 60w is the equivalent. Sorry I should have made this clear. The actual wattage for each LED bulb is claimed to be 10W with an output of 810 lumens each. All LED bulbs tried in this circuit and have been tried in other circuits. All are faultless. Odd that Murdoch had a similar problem. I shall go through my stock of LED bulbs just to be sure, but since the ones that don't work in the study do work elsewhere gives me little hope that I will find this to solve it.

 

[Fullerbull]

The LED is definitely a 240v it actually says 220-240v 50/60 Hz. They are connected in series, but then so are the ones in the kitchen and bedroom and they don't fight. However, it does feel as if they are in conflict though that is an emotion not a measurable fact!

 

[westward10]

I think you mean parallel?

 

[FatAlan]

I think you mean parallel?

I meant series, but thinking about it now you're saying that the LEDs only work when there's a filament bulb there...although it could be that 2 LEDs in series as apposed to parallel might not work due to the drop in current.

 

[Richard Burns]

Since it is not a transformer then I would move on to the situation were there is a slightly loose connection or a contamination in the wiring generating a small resistance. When the low current drawn by the LED bulbs is switched on there is not enough power to get them to operate, when the higher current is drawn with the filament lamps then this can overcome the resistance and "burn" a current path for operation. I have seen this in a socket that would run an electric blanket but not a lamp; the wires were coated in the green goo and not secure in the terminals, once they were clean and correctly terminated all was fine.
I am sure my explanation is slightly flawed but the effect is the same.
re-terminate all the conductors in the ceiling roses and switch and see if this resolves the problem.
The bulbs will be connected in parallel, even though there is a wire from one to the other the two cores connected to the same core of the wire means they are a parallel connection.

View attachment 35868

 

[Fullerbull]

Right guys, here is another piece of info. The bulb nearest to the switch is filament, the other is LED. Switch on and both light. Removed filament bulb (nearest the switch) and switched on: the remaining LED (farthest from switch) flickered and would not light. Put filament bulb back and both lights work again. The filament bulb will work on its own in either holder with nothing in the other holder. The LED won't unless the filament bulb is in one holder. It is the same story if I put the LED in the holder nearest the switch. I have just opened a new LED bulb package and inserted the new LED. Same story.

 

[Fullerbull]

Thanks Richard Burns for your suggestion - it sounds plausible. I have a slight problem in getting to the switch because it is partly obscured by a very heavy floor-to-ceiling bookcase and while I can switch on, I can't get at one of the cover screws. I'll have to move the bookcase (no quick/easy task) and examine the switch. In the meantime I'll have a look at the ceiling sockets and check if they are ok. I'll not be able to do this until this evening, but if I find anything I'll post again.

 

[westward10]

I meant series, but thinking about it now you're saying that the LEDs only work when there's a filament bulb there...although it could be that 2 LEDs in series as apposed to parallel might not work due to the drop in current.

The op said a few posts later they are series.

 

[FatAlan]

If you can, take some snaps. We like snaps. Be careful.. safe isolation.

 

[ImpededLoop]

My guess now would be a duff switch. Otherwise it can only be a poor connection somewhere but I think this would have shown up before.

 

[Andy-1960]

I'd be looking at poor connection in neutral

 

[Fullerbull]

Thanks to all of you for responding to my query. You have taken a real interest and offered some good advice. Sorry about the delay in posting again, but I had a number of other urgent jobs to attend to (like repairing my fence after the recent storms in my area). Anyway, The Problem is SOLVED. Hurrah! Today I examined both ceiling roses ('cos that was easier being more accessible)and carefully checked and cleaned the first one and followed this by replacing the second one which had a cracked bayonet fitting (plastic) which broke off when I started to take it down. I thought that was problem solved, but it wasn't that, so I spent over an hour removing books and shifting the bookcase to get at the switch. Those of you who have partners will know that inevitably there was then a bit of a delay while my wife vacuumed where the bookcase had been! I could not believe what happened when I unscrewed the switch and pulled it away: the neutral wire just flew out and hung loose. There was absolutely nil contact between the holding screw and the neutral wire (it must have been like that for over twenty years!!). The circuit was being made by the springiness of the wire pressing against the side of the neutral terminal! I tightened it up and Hey Presto the whole thing works fine. I still do not understand why I have never had even a flicker of a problem when using at least one filament bulb in the circuit, but I'm not complaining! The message seems to be that LEDs are very sensitive to resistance in the circuit and require good connections throughout, unlike filament bulbs. Thanks again to everyone for your suggestions.