Inverter problems

[Michael_374314850]

I'm having a problem with an inverter and I wondered whether anyone could help.

If I plug the inverter into the 12v fitted plug in the caravan via a cigarette lighter style adaptor then, whenever I plug anything into the inverter it just reports 'overload' and the appliance does not operate.

If, however, I plug the inverter directly onto the battery connections via crocodile clips then everything works fine.

Is it possible that there is something wrong with the way the 12v plug in the caravan has been wired? If it helps, the caravan is an '82 Ace Globetrotter.

Thanks

 

[rob_jax]

Hi Michael,

The inverter will draw a battery current roughly 20x the rated mains current.

And since you don't say what make of inverter it is, nor any relevant features, but I'd guess the problems are either:

The 12V socket in the caravan is wired incorrectly - check with a voltage meter

The wires feeding the socket are under-rated for the job in hand - and exhibit voltage drop and / or can't supply the necessary power (sounds the most likely). And the probable solution is to replace the under-rated 12V wiring with some heavy duty cable.

Robert

 

[JeremyClarksson]

If you have thin gauge wire connecting the cigar lighter socket to the battery, the inverter to the socket or both you could get a significant volts drop over that wiring and this could cause the inverter to report an overload even with a fairly light load.

As it works fine if connected direct to the battery I would guess this is the case. 12v lighter sockets are not great connectors anyway, I would go for a direct connection with a heavy guage wire to the fuseboard.

If you want to use it in the car as well use a couple of screw type connectors like those fitted on the inverter so it is easy to disconnect.

If you decide to connect directly to the battery still use a fuse.

Make sure any connections can not be shorted accidentally in or out of use.

 

[JeremyClarksson]

One other point I would not use an inverter above 300w rated and I would not plug anything above say 150W into it because of the current draw and possible problems with the 12V wiring.

As Rob says the current would be high 300W/12V = 25A and 150W would be 12.5A.

There is also the problem with battery life caused by the extra loads.

Do do not run heat appliances like toasters/hairdriers from an inverter, whatever its rating, keep to small TVs, laptops etc and do not expect to run them for too long.