Patio Panels with Polystryrene - Warning Cable DYO Builder 12 Volt

Builders who insist on installing the 12 Volt Secondary side of a transformer are doing you no saving of money. The 12 Volt side still has a volt drop and the cable size run will be much larger than a standard 230Volt circuit. The inconvenience of needing to remove there work and installing the Polystrene Approved cable (zero Hallogen Non Migratory type)

The 12 Volt Cables that I have seen Patio Builders using is not suitable for running with in the Polysyrene Panel period. I have declined to connect these Extra Low Voltage Cables.

The size of the cable has to be calculated for the Volt drop on the Secondary side of Extra Low Voltage Transformer. This 12Volt - Volt drop the cable size run would be much larger than a standard 230Volt circuit cable.

I have had Clients Say to me ... "Its just 12 Volt , Any one can do it !" Yes they can, But in Most Cases Incorectly Done. "Any one can do it its only 12 Volt" This would be true if the calculated cable for lenght x distance was calculated and the cable for Polystryene approved type was used and the electrical contractor was not connecting the 230Volt step down transformer.

So far the Builders doing this seem to think Volt drop does not count. They also do not think that the12 Volt  PVC Sheath will be effected by thePolystrene ( Perhaps they know more than the Scientist's who advise the Electrical Industry Best Practices) They also think that 12Volt under rated cable does not matters either.
( There answer is thats what we have always done ...Good luck with that Work Method Statement in 2019)

They also seem to think that installing transformers in weather proof boxs on your roof is quicker  for the Electrician and safer to work on roofs.

Quicker for the Electrician to install 230V LED  Down Lights  in the first place with Polystryene Approved Cable. The Earthing of the Metal Framed  Patio is also a Requirement too this cable is run back to theMain Switchboard its called Bonding.

Running in the control cables before the Structure is Built  to the indoor light switch positions would be sensible and working in together would be appreciated, that would make things easier for the Electrician.

Obviously more difficlt to remove Roofing Tiles or Roof Sheeting when your Builder has Abuted Over It.

Builders who insist on installing the 12 Volt Secondary side of a transformer are doing you no saving of money. The 12 Volt side still has a volt drop and the cable size run will be much larger than a standard 230Volt circuit. The inconvenience of needing to remove there work and installing the Polystrene Approved cable (zero Hallogen Non Migratory type)