Two transformers

[AndrewHarrison]

I have purchased a 5 piece low voltage down lighter set from B&Q. It includes 2 transformers, one for 2 lights and the other for 3.

If I only have one mains feed coming in do I just use a junction box to split the feed between the two transformers?

 

[Chri5]

Are they being switched together?

If so mains feed live to switch, switched live to transformer A with neutral and earth, then daisy chain switched live, neutral and earth to transformer B from A.

 

[GaryMo]

Just for information, the set you have will be Extra-Low Voltage (12V AC), not Low Voltage which includes 230V AC.

Voltage, nominal. Voltage by which an installation (or part of an installation) is designated. The following ranges of nominal voltage (rms values for a.c.) are defined:

Extra-Low: Not exceeding 50 V a.c. or 120 V ripple-free d.c., whether between conductors or to Earth.

Low: Exceeding extra-low voltage but not exceeding 1000 V a.c. or 1500 V d.c. between conductors, or 600 V a.c. or 900 V d.c. between conductors and Earth.

High: Normally exceeding low voltage.

 

[ban-all-sheds]

The IEC define a MV band between Low and High, of 1kV - 35kV.

Which is of academic interest to most people on this forum.

But, Andrew, the distinction between ELV and LV is very much not of academic interest, and it is not technical pedantry to make the correction.

It does matter - see the explanation here: //www.diynot.com/wiki/electrics:voltage-bands for why.

 

[GaryMo]

But, Andrew, the distinction between ELV and LV is very much not of academic interest, and it is not technical pedantry to make the correction.

Yet I see it on a regular basis, not just by members of forums and the like but directly from manufacturers on their packaging, instructions and specification.
How can they get it so wrong?

 

[plugwash]

Low and high are relative terms which only have meaning in context. To a power systems engineer calling the power delivered to homes "low voltage" makes perfect sense as it is the lowest voltage they are likely to be dealing with. To everyone else calling the power delivered to homes and buisnesses "low voltage" is perverse as it is the highest voltage they are likely to be dealing with.

Much as they may wish they did the IEC don't control the english language. So their defintions only matter in the standards they write or other documents that explicitly reference their defintions. Outside of that context the terms should be treated as ambiguous (e.g. try to avoid writing them and seek clarification when reading them).

 

[ban-all-sheds]

I suspect the packaging/instructions/specs error originated out of a desire to not confuse their understandably ignorant customers who would never have intuitively considered "mains" as "low voltage".

And it's just stuck.

 

[ban-all-sheds]

Much as they may wish they did the IEC don't control the english language. So their defintions only matter in the standards they write or other documents that explicitly reference their defintions.

Exactly, which is why it is important for people to realise what the official definition is, lest they read a law or regulation and think "I've not got any low voltage or extra low voltage in my house, it's all mains, so this doesn't apply to me".