2 way lighting -help!

[plumberjohn]

hello all - hope someone canhelp me.

A customer asked me about her landing light , as the bulbs don`t last long.

It`s a normal 2 way circuit with 1 switch on the landing and one downstairs in the hallway. The circuit has a feed into the cieling rose, a 2 core wire to the 2 way switch, and a 3 core strapper to the downstairs switch. Everything looks ok so far.

When I test the voltage at the fitting -250v when switched on, 32v when off!

Any ideas what to look for?

TT system, 18.6 ohm Ze, one main RCD.

Probably quite simple, but any suggestions welcome

John

 

[Lee321]

to what did you test the voltage to L-E or L-N ? is the minus relevant to the test or a typo?

my guess is you'll not find anything. just recommend not to buy the cheapest lamps

 

[plumberjohn]

tested L - N Lee, and the minus was irrelevant.

 

[Lee321]

so it works as normal per se. ? but blowing lamps often

how often?

 

[Doc Hudson]

Cheap bulbs from

 

[Evans Electric]

Likely to be cheapo lamps from Eastern Europe/ China , as said above.

The 35V when switched off shouldn't be there though, if its off, its off. Wonder if low energy lamps ,elswhere on the circuit are leaking voltage.

 

[Tooold]

Went to one of these today, cost the landlord a callout to tell him tennant using wilko bulbs!

Never found a reason for lamps not lasting other than down lights then its heat, vibration or loose terms.

 

[plumberjohn]

Thanks for all the replys. Yes there are several low energy bulbs, including the one in question, and they are probably cheapos. She says they only last a couple of months. I`ll tell her to invest in good ones. Thanks all for putting my mind at rest

John

 

[Evans Electric]

What make are these low energy lamps ? Most of ones I see are from respected makers and tend to last for ages. I thought you were talking about tungsten lamps TBH.

Sometimes finding a voltage when switched off can be switches tracking internally or very damp conditions within switch boxes.

 

[ProDave]

I get this a lot. Customers asking me to change a light fitting because bulbs don't last long. I try telling them it won't be the light fitting, but some don't believe you, so you change the light fitting and charge them. But the bulbs keep on blowing.

 

[initforthemoney]

I think you will find it is down to the unstable voltages that the DNO's kindly generate.

Couple this with cheaply made lamps and they wont last.

 

[Sidewinder]

Init,

The DNO does not generate the supplies.

The UK grid voltage is a nationally and becoming an internationally tied commodity.

It is extremely unusual for the grid voltage and frequency to move outside those specified by ESQCR in this day and age due to the control systems in place.

Baring any genuine fault situations, vandalism, or terrorism then the UK grid voltage and frequency will rarely move outside the specified parameters.

 

[Lurch]

Dodgy low voltage supply equipment can cause the voltage at the head to vary a bit though.

 

[that spark]

feedback on the neutral could be due to loose connection at board or another ceiling on the circuit