Re: post 48490 Std Wiring & Plumbing layout for caravans?

Hi Drew, Interesting circuit, make sure you have an experienced electrician tell you what type switches and relays are required if you want to build it. When mixing low voltage and extra low voltage all the equipment must be rated for 230 and the switches may need to be double pole in some positions.

This is a more complicated system than most would employ. It is specific to systems using a Plasmatronics solar regulator (or other similar ones) which has a common +ve rail. These can only be earthed in one place. Plasmatronics regulators have one +ve terminal and three -ve terminal. If you are using one of these regulators you have to be careful that only the load -ve terminal is earthed and the others are left unearthed or you short out the metering. These regulators are this way round as they were originally built to be used in telephone installations that use +ve earths. The circuit is incomplete in that there is no +ve terminal shown on the PL20 regulator box.

The other strange bit about this system is it that it allows you to run the 3 way fridge from the inverter operating off the battery supply.

If you are employing a more modern type of solar regulator like a Morning Star then you can simply connect the multi stage battery and the solar regulator across the battery without switching.

If you want to use an inverter you are better to connect it to the battery with short leads and then use a power board to supply the equipment you wish to use. If you require it to be fed through the van wiring then you need to get a qualified electrician to engineer and install the system.

PeterD