240 V inverter

[Kassan1973]

HI all ive been trying to get a simple answer on the following question , when wiring in a 240 volt inverter to a caravan to feed the entire van how does the 240 volt inlet plug get isolated so its not live when inverter is active .
A ) normally through a ac transfer switch
B) when using a inverter with a transfer switch a two seperate cables must be run to the 15 amp inlet plug on the outside of the van straight one as i inlet and one as an outlet .
I was advised to look up the enerdrive website for a diagram but it didnt really show what i was looking for

Thanks

 

[Drover]

Why ???? what do you need to run which can't be done by 12v other than coffee machine or microwave.

It is a job for a sparky anyway as it need to be signed off with a compliance plate as well, ....

 

[Hitting the road]

I may opt for a similar system, mainly for convenience sake. We do go off grid mostly when camping, the bride likes her coffee via her coffee machine and likes to use a hair dryer after a hair wash. plus I still need to work at times when away from home so use a laptop computer that needs to be charged via 240v.

I had fitted 1500W inverter to the camper trailer which was great for running the coffee machine, hair dryer and laptop as required. I had also had an RCD compliant 240v input fitted to that camper by a caravan centre and provided with a compliance certificate.
In a past life I had a 2500w inverter fitted to my boat which could run on 240v shore power, and would switch straight to inverter power if interrupted and if the gen set wasn't started. It would run the microwave oven or what ever else I wanted to on 240v off shore.

I am now looking at an Enerdrive 2500w inverter now which has a spike capacity of up to 5000w which could even run the air conditioner provided I had enough solar / battery capacity. Maybe later....

But, I would be taking it to an electrician to install for the reason drover wrote above, I know of some people who are happy to fool with 240v set up in their vans, but there are regulations and requirements to abide by. I'd hate to do a dodghy set up and see some one somewhere electrocuted...

 

[millers]

The enerdrive website states (on one of the videos) that you need a sparky (as @Drover has stated). If you are using the enerdrive unit with a transfer switch built in then the 240V into the van goes to enerdrive unit and then the enerdrive unit has another plug that goes to the caravan power points, aircon etc.
For the enerdrive unit, the power point on the unit is not used as part of this installation. It is an independent outlet.

You can choose to have the sparky wire in such a way to include the A/C or not, meaning that instead of having the outside input go to the inverter and then the inverter to everything else. The input to the inverter would be from the power point feed and then the output from the inverter to the power points.

I would also suggest that the 240V battery charger should be isolated from the inverter circuit so that it is not energised while running from the inverter (ie Battery to DC to AC to DC and back to battery does not charge batteries).

If you do not have a unit with an inbuilt transfer switch, then you need to get the sparky to wire in a manual (or automatic) one if you want to use the same power points.

There is a crude option (do not know if it is legal or what the requirements for isolation switches are), where the installation could be an outlet on the outside of the van powered by the inverter, which via an extension cord is plugged into the external 240V inlet. Issues here with 15 Amp compatibility. Again a sparky is required.

If I have not made it clear a sparky that deals with this, or is going to chase down the correct regulations is required, and you need to discuss what will and will not be able to operate with the inverter and size the inverter correctly (including cooling capacity - air flow).

Finally, as @Drover has said, is option 1 actually use an appliance that is not 240V to achieve what you want or a generator (keep it 240V). As a minimum the currents involved when converting from 12V to 240V is a multiplier of 20. That is 15 Amp 240V will require 300 amps at 12V. This means that connections on the 12V side need to be capable of handling the currents and any small increase in resistance (bad joint / contact) will result in heat (0.0001 ohm resistance would generate 9W of heat with a voltage drop of .03V). For comparison a 12V - 25W globe has a resistance of 0.5 ohms and draws approximately 2 amps.