Using Inverters In Vehicles

[Krankin]

Yes that would be right.

You won't get a shock between the two supplies i.e. Grab the active of one inverter in one hand, and the neutral of the other inverter in the other hand and you won't feel a thing.

Go on Tony, give it a go and post your results...
try this experiment too, stand in a puddle with bare feet when you try the above...

 

[Krankin]

Okay, so let me get this straight ...

If I have a 12V supply and connect two inverters to it and connect ONE device to each inverter, I have complied with the standard?

Does this mean all I need to do to comply is purchase another inverter?

If that's the case, consider it done.

Ok, the way i see it.....if you cant/dont want to go by the AS for vans etc,
just use the one inverter and run your gear through an RCD, wired up as mentioned previously and thats been tested.

 

[Krankin]

and make sure the van is bonded to this.


Haven't been through the construction site rules re. inverters but is that rule for inverters in general or just on construction sites?

You only bond back to the inveter frame...If the inverter frame is mounted isolated from the van it wont work.
If you bond back to the van, the inverter frame MUST be electrically connected to the van frame too.

Now this MAY all be in the relevent AS, just we dont know if we cant see a copy.


That clause is from as3012,
generally i dont know if there is a ruling, and I would say there is something if not similar in AS/NZ 3001:2008.



.

 

[Old.Tony]

I don't think I'll push the boundaries of common sense and stand in a puddle holding 240V LOL....

It isn't a matter of not WANTING to comply with the standards, it's just that at the moment I don't know what the standards say so the only alternative I have is to do it as safely as possible.

I think Jaycar's advice is to connect the frame of the inverter to the vehicle chassis, and all of my inverters have a connection on them for this purpose.

 

[Krankin]

Whats the purpose/why of just connecting the frame to the car body...

 

[Old.Tony]

I suppose it's an earth point? I haven't researched the 'why' on that yet. It's possible that (internally) the negative lead is connected to the inverter's frame. I might crack one open later and take a look at the circuit (inside the inverter).

 

[Krankin]

I suppose it's an earth point? I haven't researched the 'why' on that yet. It's possible that (internally) the negative lead is connected to the inverter's frame. I might crack one open later and take a look at the circuit (inside the inverter).

No, you wont find thats the case.

 

[Old.Tony]

Maybe not. I'm messing around (in my head for now) with the idea of completely recabling the van now, so that I can manage things better. The solar regulator and the CTek charger don't push power through the same shunt, so my battery monitor has no idea where things are at.

I'm also using a 100Ah gel battery and am considering changing to an Exide Orbital spiral-wound AGM, as long as the thing fits in the battery tray. Its only competitor is the Optima red/blue/yellow and I've read more disaster stories about the Optima batteries (which are more expensive) than the Exides, so that's where I'm leaning towards.

It's possible that I'll ditch the inverter altogether, opting for a 12V feed direct from the vehicle to the fridge, along with isolating the solar-charging system from the fridge power while the vehicle is running (easy enough to do with relays).

I'll spend a few days mulling this over in my head. Going to make some drawings, see if I can rework things a little smarter. There's a bit of a spaghetti factory going on in the control box at the moment, and not all of the cable is as heavy as I'd like.

 

[Krankin]

I rather like the idea of an inverter onboard though, handy little item.

 

[Old.Tony]

I may not get rid of the inverter completely. I have one in the tub of my vehicle that runs a battery charger to charge the battery, but the unit is completely isolated from the vehicle framework and no 240V wiring exists outside the box that the battery is in, so it couldn't present a threat unless the vehicle was submerged to nearly the lip of the tub. I have another inverter inside the cabin under the back seat, but this remains off most of the time.

Where an inverter in a van would come in truly handy is when you have a 3-way fridge. Under 12V, the heating element draws less power (watts) but the fridge doesn't work on a thermostat - it just runs in 'maintenance mode' and just barely keeps the stuff cool. It's done with the idea in mind that if your car is on, and you're travelling, you're not going to stop for a quick drink, bite to eat or anything because there are no shops on that part of the Tanami Track, so 12V is adequate. It's not - so I was looking for a solution to this (even though I have a 12/240V compressor fridge, I was looking at a new caravan with a 3-way and considered keeping that in there).

In 240V mode, three-way fridges run a thermostat (just like they do in gas mode). Refrigeration will be at optimum level, so even if you scamper into the van in a rest area to grab a cold drink then jump back in to continue, the fridge will return the interior to its set temperature.

Hence the idea for an inverter while moving.

It's those last two words that seem to cause all the trouble!

 

[Krankin]

I may not get rid of the inverter completely. I have one in the tub of my vehicle that runs a battery charger to charge the battery, but the unit is completely isolated from the vehicle framework and no 240V wiring exists outside the box that the battery is in, so it couldn't present a threat unless the vehicle was submerged to nearly the lip of the tub. I have another inverter inside the cabin under the back seat, but this remains off most of the time.

Where an inverter in a van would come in truly handy is when you have a 3-way fridge. Under 12V, the heating element draws less power (watts) but the fridge doesn't work on a thermostat - it just runs in 'maintenance mode' and just barely keeps the stuff cool. It's done with the idea in mind that if your car is on, and you're travelling, you're not going to stop for a quick drink, bite to eat or anything because there are no shops on that part of the Tanami Track, so 12V is adequate. It's not - so I was looking for a solution to this (even though I have a 12/240V compressor fridge, I was looking at a new caravan with a 3-way and considered keeping that in there).

In 240V mode, three-way fridges run a thermostat (just like they do in gas mode). Refrigeration will be at optimum level, so even if you scamper into the van in a rest area to grab a cold drink then jump back in to continue, the fridge will return the interior to its set temperature.

Hence the idea for an inverter while moving.

It's those last two words that seem to cause all the trouble!

just run the inverter for the fridge, keep it and its outlet completely separate from all the other systems and i cant see a problem.


.

 

[justdrinkbeer]

just run the inverter for the fridge, keep it and its outlet completely separate from all the other systems and i cant see a problem.


.

X2

You won't have any issues

 

[Old.Tony]

It will be done. One inverter per device and keep them isolated beyond the 12V connection.

We searched the Newcastle Uni library for the standards but couldn't find 'em. I think I'll investigate the standards further through some friends.

Thanks guys!

 

[Bosshog]

It taken me three weeks but better late then never.

I have the standard so please PM if you want a copy.

 

[Krankin]

GOLD!!!!

ta very muchly for that...

 

[Old.Tony]

Greatly appreciated, Gus. That's a good read.