12V transformers - life

[frediaz]

I am told that the transformers used with 12V spot lights last as little as 9 months and then you have to replace them. Is this true?

If it is true then the problem is where to locate them to find them and have access. The obvious place, in a house, is within the ceiling void between joists but then what? cut holes in the plasterboard to access them or provide removable hatches?

 

[RF Lighting]

Depends how much you pay for 'em

I would have thought that 9 months ain't very long.


I'd expect 10 - 15 years life from a regularly used Tx

You can normally access them by removing the downlighter they supply, and pulling it all through the hole.

 

[Softus]

I am told that the transformers used with 12V spot lights last as little as 9 months and then you have to replace them. Is this true?

No. They can fail very quickly or last indefinitely.

Cheap ones tend to fail more quickly; so do ones that get too hot.

If it is true then the problem is where to locate them to find them and have access. The obvious place, in a house, is within the ceiling void between joists but then what? cut holes in the plasterboard to access them or provide removable hatches?

Er, you'll have removable hatches in the form of the recessed lamps.

 

[frediaz]

But mine are only small spot lights and the transformer is in the centre of the pattern formed by the array of lights, to have the same length of cables and equal voltage, like this:

X X


X T X


X X

 

[frediaz]

clever software, it removed all the spaces between characters, see if you can ruin this one:

X..............X


X.....T.......X


X.............X

 

[Softus]

I favour one tranny per spot - less load on each tranny (therefore less localised heat) and each one cheaper to replace when they do go.

 

[breezer]

clever software, it removed all the spaces between characters, see if you can ruin this one:

X..............X


X.....T.......X


X.............X

guess what

this button is for

 

[Steve]

[code:1]X X
\ /
X - T - X
/ \
X X[/code:1]

 

[nozspark]

But mine are only small spot lights and the transformer is in the centre of the pattern formed by the array of lights

Then I would take a guess that there is an access panel in the floor above in the form of a cut floor board.

 

[frediaz]

I think it would look less ugly to put an access panel on the ceiling as if it was a ceiling rose or alarm

This is good

X X
\ /
X - T - X
/ \
X X

 

[mikeyd]

to have the same length of cables and equal voltage

Priceless.

 

[RF Lighting]

Whys that?

A longer cable run = more volts drop, so less voltage at the fitting (and therefor dimmer lights)

 

[Softus]

OOI, what would be the VD over, say, 2m, starting with 12V DC and using 0.5mm² flex?

 

[Spark123]

What wattage lamp?

 

[Softus]

Oh yes, sorry. Let's say 50W (i.e. 4.17A).