Fellow Boggers, Terry and Patti G**** wrote to me regard regrets that had not put in an inverter, and wanting to add one now with an Electrician in their area… Fine. Yes it would have been better to have our Automatic Switching built into the Inverter, but a rough variation can be done per below. But it is fraught with Pitfalls, and over the weekend I was fretting about it as it could be DISASTROUS if someone were to do it wrong…. I was worrying a little about it, and was afraid someone else could get hurt doing it wrong, so I am up at 6 AM this Sunday morning trying to get this out… Here is the email and the important features to take into account when doing this retrofit:
The Email to me at
Bushtracker:
Steve,when we purchased our van 4/06 we should have put in an inverter as we have only one 12v plug could you see any problems if we arranged for an electrician to hook up our ALESSI pure sinewave inverter to utilise the 240 plugs with a switch from 240v to 12v Terry Giles your info on the owners site is great
My response:
Thank you for the positive feedback, I am trying to be of a help on the
BOG…………….
As to your Inverter, yes you can put in a large Rotary Switch to turn all the outlets over from Mains Power to Inverter. It is a bit crude of a way to do it, and you will not have the Automatic Switching, but that is a luxury anyway… The only problem, and talk to your Electrician as there is a number of ways to solve this, but here is the problem: You will need to be very careful you do not have your battery charger on, plugged into a 240v power source, and run the other outlets off the inverter by accident. Any spikes coming through the Mains or Generator power to your battery charger, are magnified by the inverter and it kills inverters.
First of all the battery charger circuit will have to be isolated anyway, to only a 240 Mains outside power source, so the battery charger is not running on the inverter power when you switch over… But then, since the battery charger will only be on when on 240v, always left on so it is automatic, so when you plug in it comes on….. There lies the problem. When you are plugged in if you forget and the Inverter is left on, you will have both running. The inverter will be powering up your outlets AND the battery charger will be on charging the batteries. This can damage the inverter when spikes come through the battery charger, as spikes are magnified by the inverter in the 240 volt conversion from 12 volt, and it damages the inverter circuits…
Textbook Electrical Engineering might say the batteries are a surge or spike absorbing protector in this case like a spike suppressor, as they operate just like a giant Capacitor….. Correct in theory, but we have seen many a burnt out inverter, as they forgot to manually turn over the inverter to 240 mains power when they plugged into a dodgey power source like SWER Outback power line… SWER has surges and spikes as people downstream turn on and off pumps and larger equipment.. So maybe you should put in a noticeable red Pilot light when the inverter is on? Or it is a complex Rotary switch wiring job for your Electrician… And he will have to add an additional RCD safety device as the power leg to the charger will have to be taken off before the existing RCD that protects the other Outlets... Which ever solution the Electrician does, make sure he knows and understands this problem….
Summary: Boggers to be: Iif you are in two minds about an Inverter, and think you might want one for the convenience of quick preparation of meals or precooked batches on the road with a microwave, or the quick cuppa to brighten you up when you are running late in 45 seconds with a travel mug bunged into the microwave instead of the 20 minute stop…. If you think you might want one, get us to pre-wire the van for future inverter…
Existing Bogger with new or pre-loved Bushtrackers thinking of adding an inverter: Be Careful, to understand the two problems above. First the issue of isolating the Battery Charger so the Inverter does not run it as that is a resulting power loss, not charge in the closed loop… And secondly, the circuit taken off for the Battery Charger could be done with a Rotary Switch on the leg before the existing Circuit Breakers, so the RCD (Residual Current Device safety feature like the International GFI Ground Fault Interrupter) would not be in the loop… And additional RCD needs to be added for the Isolated Charger. The RCD function is to trip the circuit like a circuit breaker and shut the power off, any time it detects power going to ground, as in a short circuit from defective wiring in an appliance. In theory this protects you from being electrocuted, as any momentary power to ground within the appliance or circuit, or even your body, should trip the RCD.
Friends, it is a lot of Technical mucking around to add this as a retrofit, and do it right… Make sure you have a Licensed Electrician do it for you… And above all, make sure he understands the two points above and compensates for them, with how he does this. Please.
It is early Sunday morning, and I had a little wine last night, I think the above is correct with no typos, but I will review it on Monday and make any revisions or notes should I find I have left out something. But I think the two problems above are the primary issues of SAFETY that I want to warn you about, and I think I have communicated them well enough that if you print this off and your Electrician studies it a few times, he will get the idea and compensate for it… BE CAREFUL…
Regards, ………….Ranger out Scouting the trail…..
