INVERTER QUESTION

liz795 · Veteran Member

INVERTER QUESTION

Baz421 · Guru

liz795 wrote:
Hi all
We've been told that we need different or extra power points for an inverter, i thought if we installed a inverter that we would use the existing power points in the van ( is this correct. )
As they will start building our van in a few weeks, so we may have to notify them
thanks liz

No expert Liz - they will give you more info re Class 1 appliances, as there are some very qualified people here.

However if you connect 2 or more Class 1 appliances (appliances with an earth pin connected) you need one of these (not necessarily this brand but an RVD)

http://www.safelec.com.au/product-applications.html

Aus-Kiwi · Guru

You can't .MUST NOT have two 240v supplies at one time .. So you require a system that isolates the inverter when plugs into mains..
He could be referring to seperate power points from inverter ONLY ..?
The 240v side must be wired up by electrician ...With protection ...

PeterD · Guru

Liz, You can power your vans power points from either the mains or an inverter but not both at the same time. The change over circuitry necessary to do that is quite expensive to install. You also have the problem of someone inadvertently overloading the inverter or the battery. Providing a separate double power point for the inverter will be much cheaper and also reminds users that they have limited power available.

liz795 · Veteran Member

Thanks for your comments
we should have thought about all this prior to signing our final plans. But reading about inverters on this site ,we were under the impression that we could add the inverter at any time cheaply.
We contacted the dealer and they wanted $2500 for changing wiring, plans and installation, etc they weren't interested. and would not let us supply the inverter , we like the van but since we picked colours, signed contracts they have been less than accommodating were a bit disappointed. THATS LIFE
REGARDS LIZ

brukay · Member

I understand your predicament but as a builder myself I can tell you that have to accommodate serious changes to the design and other details after the job has been finalised or started can be a real pain in the **se. It can create otherwise unforeseen problems and upset subtrades and schedules. Considering this and the price they wish to extract and the points made by others I reckon your best option is to get a good electrician to fit your inverter and a gpo or two (to the relevant Stsndard) after you take delivery. If you choose locations carefully in consultation with your sparky this should not be too difficult a job.

Bruce and Bev · Guru

when we bought our new van from the dealer, their sparkie installed the invertor we supplied to them, It is buried underneath a seat and I have no idea how it is wired up.

When we are plugged into 240v mains supply we run the TV, air con or electric heater, lighting and whatever. We have our laptops, tablets and phone chargers plugged into a multiboard which is the sole power source from the invertor.

Its been this way for the past 18 months.

Should I be getting this checked out by a sparkie to see if the Dealers tradie did it right - he also fitted additional solar panels and batteries and some other electrical works at the same time

Aus-Kiwi · Guru

Power would go of intermittently when changing from inverter to mains ..
A power limiting breaker is best fitted on AC side of inverter to prevent overload on the DC side..
Depending on inverter wattage ...

liz795 · Veteran Member

thanks for all your posts we will sort it out, after reflection it wont be as big a problem as we thought

Baz421 · Guru

Liz I can offer you some advice for after manufacture fitting, as ours was fitted (reluctantly) after building by the post build section of the factory.

We have a small (about 150W) inverter that runs sat box, laptops, chargers for camera's etc when needed.

This one is wired through my bedhead to the inverter in the boot, so I can switch on/off lying in bed.

We also have a 1000W inverter we hardly ever use but it was used on summer days to run the truck fridge without the need to start the truck and charge 2 nd battery. The truck now has a solar panel to charge the 2nd battery so we hardly ever use the 1000w inverter. It too is run through very heavy cable past my bed with boat isolator to turn on/off.

NOW FOR THE EASY PART.

We plug the 240 power cord direct to EITHER inverter and DIRECT into the normal van 240V socket, so the power supply goes to the van as if it was plugged into mains.

You then switch OFF what you don't need (say toaster, 240V hot water, microwave, heaters) and use the power for whatever is within the rating of the inverter.

HOWEVER SAFETY COMES FIRST SO YOU NEED AN RVD FITTED IF YOU DO THIS. See my previous post and link.

You don't have to run the cables inside the van and you can position the inverter(s) in the boot near the batteries. Most competent electricians can do this for you (mine did).

I'll send you my phone number if you need more info - just PM me.

EDIT Here's the RVD we had fitted.

http://www.powersafe.net.au/wp-content/uploads/2015/03/PDF30.pdf

-- Edited by Baz421 on Saturday 24th of October 2015 10:31:41 PM

The Doo crew · Senior Member

My sparky just fitted a three position changeover switch to the existing load centre box & a RVD next to the main breaker. He insisted I fit the inverter myself as he didn't want to get involved with high amperage DC cables & that is my area of expertise. Inverter in the boot with very short cables to the house battery's was an easy fit, fitted ducting for the fan as it does generate a bit of heat under load. Changeover switch has " shore supply" off & "inverter" positions, just switch to whatever we need. Ours is a 3000w 24v inverter as we run our split aircon from it when required. Mostly gets used for the toaster as the cook say's nothing cooks perfect toast like the pop up toaster, turn it on in the galley when she needs it, turn it off when finished. The RCD & RVD solve the class 1 & 2 appliance issues that seem to be discussed with such vigor.

Phil C · Guru

Hi all, ah this is an old dearly loved chestnut.

We have a 2500W inverter connected by very short heavy cables to the battery via a 100 A breaker. I have decided against a RVD or RCD as the machine ONLY get used for the electric blanket on a very cold night (class 2) and to charge the drills etc when out and about. Mind you I only ever have ONE appliance at a time on the inverter.

While I agree with the discussion on safety and the need of a RVD or RCD I consider it an overkill for what we are doing.

I would never agree about hard wiring the inverter into the caravan GPOs (power points) personally I think that's flirting with issues. The only way to do this would be seperate circuits and green GPOs.

Cheers

NIftymac · Newbie

Just went through this discussion when ordering our new caravan, first told we must have separate GPO's (power points) for Mains and Inverter supply! was not happy about that "solution" then found that Projecta inverters (think > 2000 watt models?) have models that now handles auto switching between mains supply and Inverter supply, called - 12V 2000W Pure Sine Wave Inverter with Automatic AC Transfer Switch.
www.projecta.com.au/Products/Inverters/Intelli-Wave.aspx[iframes]/4/

So the mains feeds in via the Inverter , and then if you lose AC mains or you move to off grid, then the same power points are supplied from the inverter, still using all the same safety breakers etc etc.
So just one set of GPO's needed.

cultana · Senior Member

NIftymac wrote:
Just went through this discussion when ordering our new caravan, first told we must have separate GPO's (power points) for Mains and Inverter supply! was not happy about that "solution" then found that Projecta inverters (think > 2000 watt models?) have models that now handles auto switching between mains supply and Inverter supply, called - 12V 2000W Pure Sine Wave Inverter with Automatic AC Transfer Switch.
www.projecta.com.au/Products/Inverters/Intelli-Wave.aspx[iframes]/4/

So the mains feeds in via the Inverter , and then if you lose AC mains or you move to off grid, then the same power points are supplied from the inverter, still using all the same safety breakers etc etc.
So just one set of GPO's needed.

In my latest van, that I bought by mistake, I had one of these installed 12V 2000W Pure Sine Wave Inverter with Automatic AC Transfer Switch.

web ref: http://www.projecta.com.au/Products/Inverters/Intelli-Wave.aspx#!prettyPhoto

As NIftyma said When on battery this drives the AC outlets. When on AC outside source the inverter switches to the outside AC source.

BUT get installed by an electrician and if you are in the build phase have it done when they do the electrics.

My van also has some 12 volt outlets as well. There is only 2 built in item that need 240 volts in the van, microwave and a hot plate on the 4 burner stove. I wanted an inverter to charge the laptop and camera battery. Fridge is a 12 volt one, no 3 way fridge like most apparently.

oldtrack123 · Guru

Phil C wrote:
Hi all, ah this is an old dearly loved chestnut.

We have a 2500W inverter connected by very short heavy cables to the battery via a 100 A breaker. I have decided against a RVD or RCD as the machine ONLY get used for the electric blanket on a very cold night (class 2) and to charge the drills etc when out and about. Mind you I only ever have ONE appliance at a time on the inverter.

While I agree with the discussion on safety and the need of a RVD or RCD I consider it an overkill for what we are doing.

I would never agree about hard wiring the inverter into the caravan GPOs (power points) personally I think that's flirting with issues. The only way to do this would be seperate circuits and green GPOs.

Cheers

Hi Phil

Any CORRECTLY wired inverter into the van 240V system is just as safe as any RCD PROTECTED mains SUPPLY.!! wink wink

With your idea of green GPOs, how many would you have on a large inverter?

How would you limit use to only one class1 at anytime?? biggrin

-- Edited by oldtrack123 on Monday 26th of October 2015 09:37:43 AM

Aus-Kiwi · Guru

Yea well? One on each circuit .. Depends how rules are inerptided ? It's essentially one supply on main wired circuit ..
Anything with high load ? A generator is best .. Thinking about that ? Our motorhome has two supplies .. If you include generator..
Both CANNOT be live at same time though...btw RVD is RCD replacement .. Has better protection..

Jaahn · Guru

Phil C wrote:
Hi all, ah this is an old dearly loved chestnut.

We have a 2500W inverter connected by very short heavy cables to the battery via a 100 A breaker. I have decided against a RVD or RCD as the machine ONLY get used for the electric blanket on a very cold night (class 2) and to charge the drills etc when out and about. Mind you I only ever have ONE appliance at a time on the inverter.

While I agree with the discussion on safety and the need of a RVD or RCD I consider it an overkill for what we are doing.

I would never agree about hard wiring the inverter into the caravan GPOs (power points) personally I think that's flirting with issues. The only way to do this would be seperate circuits and green GPOs.

Cheers

Hi smile

Not to be critical but only for the benefit of those who are looking for solutions, I will comment.

If you only want to run small items, eg electric blankets, chargers for drills or phones or laptops etc, or even a TV or fan, then using a large inverter like a 2500W may be pretty inefficient. Having a small one say 150-250W may use considerably less power for these sort of things. hmm

In another situation I replaced a larger 1000W inverter with a quality 300W smaller one and reduced the DC current draw from the battery by half, using loads around 100-150W. I now have a small 150W modified square wave inverter to use for these purposes in my MH. Very low current draw. So if you want to reduce your DC power use then do not oversize the inverter just to cove a mythical item you think you might use one day. Buy another panel instead. wink

Jaahn

-- Edited by Jaahn on Monday 26th of October 2015 08:35:34 AM

-- Edited by Jaahn on Monday 26th of October 2015 01:00:52 PM

oldtrack123 · Guru

Aus-Kiwi wrote:
Yea well? One on each circuit .. Depends how rules are inerptided ? It's essentially one supply on main wired circuit ..
Anything with high load ? A generator is best .. Thinking about that ? Our motorhome has two supplies .. If you include generator..
Both CANNOT be live at same time though...btw RVD is RCD replacement .. Has better protection..

Hi

A RVD is not a RCD replacement !!

It works in conjunction with a RCD to:

[a] give full protection on fully isolated supplies

As an additional line of protection with non isolated supplies.

Baz421 · Guru

oldtrack123 wrote:
Aus-Kiwi wrote:
Yea well? One on each circuit .. Depends how rules are inerptided ? It's essentially one supply on main wired circuit ..
Anything with high load ? A generator is best .. Thinking about that ? Our motorhome has two supplies .. If you include generator..
Both CANNOT be live at same time though...btw RVD is RCD replacement .. Has better protection..

Hi
A RVD is not a RCD replacement !!
It works in conjunction with a RCD to:
[a] give full protection on fully isolated supplies
As an additional line of protection with non isolated supplies.

Agree. Ours is connected to the RCD (don't ask me the tech side) as published by the manufacturer.

Aus-Kiwi · Guru

You guys running un earthed systems ?

Phil C · Guru

While I agree with all you have said PeterQ, I am satisfied with the way our system is working and have never had an issue.

The single green GPO would just about ensure only one appliance is used, anything else in my opinion is folly.

Hope you are well, cheers

Phil C · Guru

I agree Jaahn, but efficiency is something I'm not concerned about as we have a battery driven inverter on solar.

As far as the rest is concerned, it works for me and that's all that matters

Cheers

oldtrack123 · Guru

Aus-Kiwi wrote:
You guys running un earthed systems ?

Hi

Perhaps explain what you mean by "Unearthed system"????

[a] E.N but not "earthed' to mother earth

Fully isolated ,no neutral, but still with earth wiring.

A RVD/RCD combo give shock protection to earth with the lot!

-- Edited by oldtrack123 on Tuesday 27th of October 2015 12:15:30 PM

liz795 · Veteran Member

wow i was expecting 2 or 3 replies, but this seems to be a common occurrence to install an inverter after its build, or for a second hand van
thanks again for all your thoughts experiences and we will take all your advice on board
THANKS Willy

PS any preference on the make and model for a inverter,and what size . For perhaps electric blanket, battery for drills , auto satellite dish, tv, would run if free camping

WE WILL HAVE 2 120 AMP batteries and 3 120 solar panels on the roof

-- Edited by liz795 on Tuesday 27th of October 2015 06:57:44 PM

-- Edited by liz795 on Tuesday 27th of October 2015 07:06:33 PM

Aus-Kiwi · Guru

oldtrack123 wrote:
Aus-Kiwi wrote:
You guys running un earthed systems ?

Hi
Perhaps explain what you mean by "Unearthed system"????
[a] E.N but not "earthed' to mother earth
Fully isolated ,no neutral, but still with earth wiring.
A RVD/RCD combo give shock protection to earth with the lot!

-- Edited by oldtrack123 on Tuesday 27th of October 2015 12:15:30 PM

RCD doesn't work at its best on un earthed, ( bird on wire) where the RVD definnately does...

oldtrack123 · Guru

Aus-Kiwi wrote:
oldtrack123 wrote:
Aus-Kiwi wrote:
You guys running un earthed systems ?

Hi
Perhaps explain what you mean by "Unearthed system"????
[a] E.N but not "earthed' to mother earth
Fully isolated ,no neutral, but still with earth wiring.
A RVD/RCD combo give shock protection to earth with the lot!

-- Edited by oldtrack123 on Tuesday 27th of October 2015 12:15:30 PM
RCD doesn't work at its best on un earthed, ( bird on wire) where the RVD definnately does...

A RCD CANNOT WORK on an unearthed system.

Aus-Kiwi · Guru

oldtrack123 wrote:
Aus-Kiwi wrote:
oldtrack123 wrote:
Aus-Kiwi wrote:
You guys running un earthed systems ?

Hi
Perhaps explain what you mean by "Unearthed system"????
[a] E.N but not "earthed' to mother earth
Fully isolated ,no neutral, but still with earth wiring.
A RVD/RCD combo give shock protection to earth with the lot!

-- Edited by oldtrack123 on Tuesday 27th of October 2015 12:15:30 PM
RCD doesn't work at its best on un earthed, ( bird on wire) where the RVD definnately does...

A RCD CANNOT WORK on an unearthed system.

Yep why I said RVD takes over.. Text for you .. Should have said fills the gap..

wasn_me · Guru

I want to fit an inverter under the bed with a dedicated power point. I only use it to charge lap top, cordless drill, & run a bug zapper.

What's a green GPO??

It is a 380 watt continuous output. What size fuse should I put on the 12 volt supply?

Cheers Pete

oldtrack123 · Guru

wasn_me wrote:
I want to fit an inverter under the bed with a dedicated power point. I only use it to charge lap top, cordless drill, & run a bug zapper.
What's a green GPO??
It is a 380 watt continuous output. What size fuse should I put on the 12 volt supply?
Cheers Pete

Hi Pete

You would need a good heavy duty 40a FUSE to run it to capacity

You will require a licensed electrician to install that dedicated GPO

It shall be double pole!!& correctly wired!!

Nothing special about the "green" outlet except it's colour wink

-- Edited by oldtrack123 on Wednesday 28th of October 2015 06:47:02 PM

wasn_me · Guru

Thanks Peter, I have never heard of a green GPO. I thought the way it was being discussed here it may have been a GPO without a earth socket, so you could only use internally earthed appliances. Cheers Pete