Outside Lights

[ivormills]

I posted this problem some time ago but I stil cannot resolve it. I have six outside lights, mains through an RCD. They have worked fine for years, so when they did not work I checked for damp, loose connections etc and all looked fine. On the first light in the chain I checked and had power at the connecters and also at the pins in the bulb holder (bayonet lamps), this was also true for the last light in the chain. I noticed I had power on the live and the neutral side, is this normal? I am foxed, I have power but no lights! Any help would be appreciated.

 

[JohnD]

What have you been using to test for voltage?

I strongly recommend the use of a Multimeter.

If you have a neon screwdriver or non-contact stick, put it in the bin.

 

[bernardgreen]

If you have live (power) on both pins of a lamp holder then you neutral is open circuit ( other lamps making the link from live to the open circuited neutral wire )

 

[ivormills]

If you have live (power) on both pins of a lamp holder then you neutral is open circuit ( other lamps making the link from live to the open circuited neutral wire )

Thanks for your reply, sorry, not being too technically minded, can you explain what this means and how I resolve the issue? Thanks

 

[JohnD]

You have not said what you tested with yet.

A neon screwdriver or a non-contact stick will often give incorrect indications.

 

[ivormills]

You have not said what you tested with yet.
A neon screwdriver or a non-contact stick will often give incorrect indications.

I did use a neon screwdriver. I do have a digital multimeter, but I have never used it because I am unsure of the functions, and I have lost the instructions

 

[JohnD]

How to use a multimeter

http://www.doctronics.co.uk/meter.htm#digital

 

[ivormills]

Thanks John, I have looked at the link and it says

For safety reasons, you must NEVER connect a multimeter to the mains supply.

Ummm maybe it means somthing other than testing voltage?

 

[JohnD]

You can if you have set it to AC Voltage 200-500V

 

[bernardgreen]

How to use a multimeter

http://www.doctronics.co.uk/meter.htm#digital[/QUOTE]

Relates to multi-meters used for electronics. ( where the voltages are almost always less than 50 volts ) Some of these meters are NOT capable of measuring above 199 volts full scale so would be no use for mains electrical work. And some have standards of insulation where they would be un-safe with 230 volts on the probes.

 

[sm1thson]

the link is aimed at DC circuits (allthough is a usefull link as the testing priciples remain the same) it mentions AC but it does say

Every constructional project descirbed in Design Electronics works in this way.

hence the warning you quoted.

i.e. here are some dc circuits go play with them, this is what the AC bit is for but dont go play with the mains.

edit: I'm even slower today than usual!

 

[ivormills]

Fine, that seems to clear that point up
So, armed with my multimeter, going back to my original problem, what should I be testing for and what fault/s should I be looking for?

 

[JohnD]

If you have a string of lamps, test across the prongs, and I bet you you will find there isn't really mains voltage between them. Your neon screwdriver was probably misleading you, as they often do.

You go back to the place in the house where the circuit originates. You will probably find a blown fuse in an FCU, or a wire has come out somewhere, or a cable has been damaged (especially outside) or loose at a lampholder.

If there is no evidence of that kind of fault, you can test for voltage at the switch and upstream or downstream of it.

 

[ivormills]

Thanks John, and everyone who replied. I will carry out the tests you suggest. It may be a couple of days before I can get out there again, but I will get back and let you know how I get on.
Once again, many thanks.

 

[DESL]

Ivor

I think it may be safer if you can test the circuit with power off.

How are the lights connected to the house?

Is there just a light switch or do you have a fused connection unit supplying lights?