Home Made "Load Monitor".

David Mantell has been busy again and has produced a document describing how to make a manual "load monitor" for your van,David's instructions are reproduced in their entirety below:-

I feel that the Alde load monitor is a really great idea to prevent your electrical supply from site tripping out with all the embarrassment that this can bring. However, the cost of the unit at over £40 is exorbitant. A simple domestic energy monitor that measures current is all that is needed to keep an eye on the total electrical consumption.

The Alde system is good in that it automatically reduces the electrical heating whilst other items are consuming energy, however if other units (microwave/cooker hob/fan heaters for the awning etc) exceed the site supply, then the Alde cannot compensate and the site trip will ‘blow’.  The system described here is a manual system (ie you need to keep an eye and manually turn on/off items that consume energy). The major advantage is that the cost is much lower; mine cost me £10 secondhand from ebay!

Most energy monitors display kilowatts but there are some that can also directly display current in amps – one such monitor is the Owl CM113A/CMR113A  this has a similar ‘clamp round’ sensing  coil that is fitted around the positive supply cable. This is in turn connected to a small transmitter that resides in the bottom locker. The separate indicator unit is wireless and can be placed anywhere inside (or outside) the caravan. This unit indicates total current consumption and hence the user can make simple choices on what is on and off to limit the total consumption to below the site supply. I have this installed in my Cadiz for a while now and works extremely well.

One word of warning – most energy monitors only indicate watts/kilowatts – whilst this will work,  it will need you to divide this reading by the site voltage to get the current consumed – bit of a pain as site voltages are somewhat variable especially on the continent!  My suggestion is to monitor ebay and wait until a suitable unit becomes available.

If this is of any interest, I would be happy to provide any further details you may need – send a pm to Ian who will pass them on to me. 

As usual,thank you David.

Ian