Replacing Halogen Lights - whats Live and whats neutral

[ColJack]

set it to AC volts 240+ ( usually 500 on the meter.. )

take the cover off the black jusction box with the white wire going in to it and there should be 2 terminal blocks.

put the red and black leads onto each terminal and take the reading..


as for 12v vs 240v..
in a bathroom then 12v is definitely the way to go..
kithchen 12 or 240 is fine..

do these 2 white wires have a small circular ceramic conector on the lamp end?
do the lamps have 2 points sticking out of them?

 

[maderic]

Yes they do have the small ceramic connectors on the lamp end to fit the two thin prongs on the old bulbs themselves whereas the new halogen bulbs dont-they have two knobby type things which push into the connector and turn to secure. Its amazing what you learn after some time here. Its now quite obvious to me that both my systems are this low voltage type and that the new stuff I bought is 240v. Whilst lying in bed last night the thought came to me to why not do away with the transformer setup in the kitchen (because by dumping the transformer from each fitting in the ceiling I can then easily by colour see in the two core cable running into the transformer whats live and whats neutral?

What do you think of that? I'll have the power off of course!

One more thing.In both the setups over the years these halogens are prone to failing quite regularly and some fittings do not tend to last more than a couple of days. Is this a faulty transformer do you think?

Another strange thing is that I'm pretty confident that in the kitchen each light is attached to a transformer but for the bathroom after inspection in the loft there is only one transformer for 4 lights. Would this be usual?

 

[bernardgreen]

Its now quite obvious to me that both my systems are this low voltage type and that the new stuff I bought is 240v. Whilst lying in bed last night the thought came to me to why not do away with the transformer setup in the kitchen (because by dumping the transformer from each fitting in the ceiling I can then easily by colour see in the two core cable running into the transformer whats live and whats neutral?

Being able to see the colour is a small benefit. Is it worth the cost and work involved in changing the light just for that small benefit ?

One more thing.In both the setups over the years these halogens are prone to failing quite regularly and some fittings do not tend to last more than a couple of days. Is this a faulty transformer do you think?

Short life time is a common problem. Many reasons, they get very hot in a ceiling with limited venialtion to cool. vibration low cost = poor quality etc etc etc

Another strange thing is that I'm pretty confident that in the kitchen each light is attached to a transformer but for the bathroom after inspection in the loft there is only one transformer for 4 lights. Would this be usual ?

This was the original (often better) way, one transformer feeding several lights.

What ever you do make sure that the wires / cable do not touch or lay over the lamp fitting as the heat will damage the cable. Itis often better and easier to put the stiff twin and earth cables into a junction box and from there take a high temperature ( silicon or butyl ) flexible cable to the lamp. ( similar to the way the transformer has the stiff twin and earth away from the heat of the lamp ) If the lamp damages the flexible it can be replaced while the cables remain un-damaged.

 

[maderic]

Bernard, now youve got me really confused. I would have thought that the cheapest and eaiest way to do this seeing that I have already bought these 240v bulbs/fittings would be to abandon the transformer setup by cutting the cable to the transformer and just connecting the live and neutral to the relevant connectors on the new fitting?

 

[mo2]

Bernard, now youve got me really confused. I would have thought that the cheapest and eaiest way to do this seeing that I have already bought these 240v bulbs/fittings would be to abandon the transformer setup by cutting the cable to the transformer and just connecting the live and neutral to the relevant connectors on the new fitting?

He's talking about the benefits of different transformer setups, he also said to join the mains cable to a more heat resistant mains cable before connecting to the mains downlighters.