inverter location setup

RobDor · Veteran Member

inverter location setup

Wanda · Guru

Hi, ours we had installed from build time, 2000wtt wired up so that when on all power points and microwave work off 240vlt. So so easy
In your case why not contact a sparky and see what they recommend, like a lot of things it just depends on your budget$$, check and see what opions are available with a retro fit!
2000watt is a good size

I think from memory location is best as close as possible to your batteries, or was that for the battery charger??, not sure from memory, sparky will help there also
good luck
Ian

-- Edited by Wanda on Wednesday 20th of October 2021 08:43:24 AM

Whenarewethere · Guru

Firstly don't get a 2000 watt inverter just in case you need it. Work out precisely what you want to run.

Get a smaller 750 watt Birko kettle if you intend on boiling water, actually get one anyway.

As others have mentioned due to inefficiencies, rule of thumb divide watts by 10 & not 12, so for a 1000 watts you will draw a 100 amps.

Batteries have an increasingly lower capacity with a higher current. So keep amps as low as you can.

Put the inverter close to the batteries & calculate wire resistance for the total length of + & -

No point throwing away 10% or more heating up wires between battery & inverter when one probably doesn't have enough battery AH in the first place.

Mike Harding · Guru

The answer is... any way you like.

Keep in mind you may wish to switch the inverter off when it's not in use as it will consume approx 750mA (9W) in its quiescent state - crawling around to do that is not much fun. Some inverters (eg. Victron, which I recommend to you) have the ability for a remote on/off switch.

I have mounted mine in a cupboard and run a 240V lead from it through the floor of the van to a female 15A socket, this socket may be plugged into the van's main 240V input connector thus powering the whole van from the inverter. I have done it this way as it means all the van's 240V sockets are powered but I can also easily disconnect the inverter and connect the van to my generator instead. Additionally doing it this way means there is *no* possibility I can ever accidentally connect the inverter to the generator = bang!

I am not a fan of cheap inverters for a number of reasons but if you do buy one ensure it has good airflow and check it regularly by touch - if it's at all uncomfortable to touch there is a problem. Also, with cheap inverters, switch them off at night and ensure your smoke alarm is working. Spend a few more dollars and buy a Victron it's a *so* much better product than the E-bay stuff.

Peter_n_Margaret · Guru

It should be positioned close to the battery to minimise the size and length of the DC cables.
Most common inverters are NOT designed to run more than one outlet.
If it has a socket outlet it is not designed to to be hard wired and feed multiple outlets. Those that are are also available and need to incorporate an RVD for better electrical safety. They need to be installed by a licensed electrician.
The electrical power of the smallest inverter can kill you as quickly as the power at home.
Cheers,
Peter

RobDor · Veteran Member

Thanks all, some great tips there and a few things I had not thought of !! We have a kettle that we boil on gas, so no problems there. The max draw appliance at the moment is 1100 watts for our coffee machine and we only use once a day. Intend to use on it's own for the few minutes that it takes. Will have to scout the van and work out the mechanics of it before just buying one I think. Could always go instant coffee when times are rough, but dread the thought .........ha ha ! Cheers

kgarnett · Senior Member

It is my understanding that a plug connected isolated inverter or generator (without internal RCD protection) may be connected to multiple double pole GPOs via a 3pole changeover switch and RCBO connected as per AS/NZS 3001:2008 fig 3.1. The changeover switch switches between mains supply or inverter/generator

If the inverter incorporates RCD protection, it must be permanently connected only (plug & socket not permitted) . It must also be connected into the system wiring via a two pole changeover switch and RCBO connected as per AS/NZS 3001:2008 fig 3.2. The changeover switch switches between mains supply or inverter/generator

As mentioned previously it must be installed by a licensed electrician.

Ken

Possum3 · Guru

RobDor wrote:
Could always go instant coffee when times are rough, but dread the thought .........ha ha !

You could always just use a Percolator Amazon.com: COLETTI Bozeman Camping Coffee Pot Coffee Percolator Percolator Coffee Pot for Campfire or Stove Top Coffee Making 9 CUP (9 CUP): Home & Kitchen

Whenarewethere · Guru

RobDor wrote:
Could always go instant coffee when times are rough, but dread the thought .........ha ha ! Cheers

We almost do this on purpose in the outback & if looks could kill we would be long dead!

https://thegreynomads.activeboard.com/t65068305/ground-coffee/

Are We Lost · Guru

As noted earlier, it's better not to oversize the inverter too much. The larger the inverter the larger the standby current (usually). Check the efficiency in the specs as this not only affects draw from the battery, but also heat generated in the cabinet. But pretty much any reasonable quality one will be around 90% or better efficiency.

Then make sure to get a sine wave model. The modified sine wave inverters are cheaper but some devices don't like running on them. I had one (on a boat) and we found that one laptop power adapter worked, but not another identical model. The working one ran hotter than when on mains power.

Wanda · Guru

Re my origina post
Ours is a 2000watt Projecta which is wired up to all power points and the microwave. We only turn it on when it is needed, not sure why, but when the 240vlt power lead is plugged in you must have the inverter on to accept the 240vlts to all the power points, just the way its been wired and causes no issues.
I believe Projecra could be labelled "cheap" and nasty by various posters on here, fine thats their opinion.
The fact is that after 5 yrs of being used on both short and long trips, 2 and more months, with mainly free camping, it has NEVER failed, ever
You don't have to spend a fortune in my opinion and experience
Ian

Craig1 · Guru

we ran ours to one dedicated outlet, double pole, through conduit. Unit is very close to battery, so a small pain to turn on and off.

Mike Harding · Guru

Wanda wrote:
I believe Projecra could be labelled "cheap" and nasty by various posters on here, fine thats their opinion.

That's why I said I didn't like them for a "number of reasons" and, yes, that is my professional opinion.

Most cheap inverters will not have RCM compliance - an Australian safety compliance requirement. Most will not have a "C Tick" and/or comply with AS61000-6-3 for EMC emissions. Many (most?) will not have over temperature shutdown etc....

They may seem to you to work OK but there are big differences between Chinese cheap inverters and the quality products.

Mike Harding · Guru

kgarnett wrote:
It is my understanding that a plug connected isolated inverter or generator (without internal RCD protection) may be connected to multiple double pole GPOs via a 3pole changeover switch and RCBO connected as per AS/NZS 3001:2008 fig 3.1. The changeover switch switches between mains supply or inverter/generator

If the inverter incorporates RCD protection, it must be permanently connected only (plug & socket not permitted) . It must also be connected into the system wiring via a two pole changeover switch and RCBO connected as per AS/NZS 3001:2008 fig 3.2. The changeover switch switches between mains supply or inverter/generator

Interesting: I think I have a copy AS3001 somewhere, I'll try and dig it out.

From your description in your first paragraph I cannot see their reasoning:

In my caravan, which I assume is wired to the standard, earth and neutral are not bonded so a three pole C/O switch will float the van even if it's still plugged in to a caravan park supply. This being the case an RCD will not operate under fault conditions and as my Victron inverter is internally current limited it will never deliver sufficient current to trip a MCB.

It may be they were trying to account for inverters which may not have full isolation between 12V and 240V? I suspect they are, and should be, an illegal item in Oz these days?

Of course, an advantage of floating the van/inverter is that it makes it far harder to receive a shock in the event of a faulty appliance. Although, in reality, I suspect most appliances used in vans are double insulated.

Thanks for your input.

Whenarewethere · Guru

I have a Eaton equivalent 3.0kVA 2700 watts UPS (uninterruptible power supply) to power computers, so basically an inverter with six 7AH sealed batteries $2800 today replacement cost, plus additional batteries at more cost.

Over the years I have pulled apart the UPS, disconnecting batteries first not to kill myself, to clean the dust out. It is frightening how much dust gets into these things.

Anyway, when one sees the build quality of a professional inverter, I wouldn't touch a cheap one with a barge pole.

kgarnett · Senior Member

Mike Harding

PM sent to your email addr.

Ken

-- Edited by kgarnett on Wednesday 20th of October 2021 04:38:44 PM

Peter_n_Margaret · Guru

Craig1 wrote:
we ran ours to one dedicated outlet, double pole, through conduit. Unit is very close to battery, so a small pain to turn on and off.

That is fixed wiring and needs to be installed by a licensed electrician.

Cheers,

Peter

Craig1 · Guru

and it was, I had never heard of double pole gpo till I went to my sparky to make sure I was doing the right thing

SoloMC · Senior Member

As others have said, close as possible to the batteries. It you want it hard wired, you must have a sparkie install it. If its just one with a 3 pin plug outlet then you can do it yourself. Projecta make one with a remote control so you dont have move stuff to turn on/off. 1st off, determine what you NEED to run from it. I just use mine for the laptop and other small draw stuff

Dick0 · Guru

RobDor wrote:
Hi, looking at installing an inverter, not sure of size yet, minimum 1000watt, maybe 2000. I understand most are either under bed, in boot or under cupboard etc. How do you setup the powerpoints ? do you hard wire a couple of dedicated points to the inverter, or do you just run an extension from the inverter to the appliance you're using ? Not sure what the go is is. Thanks

Hi, my batteries are under bed. Inverter is screwed beside bed about 40cm from batteries. It is a 2000w/4000w peak. I can reach down easily to turn it on or off. I run a 5mt extension cable from it to where the appliances are...not hard wired in. The appliances I use are: Coffee machine, Toaster, Sandwich press & Microwave...all short term usage appliances of high wattage. Never a problem.

nomadz · Veteran Member

Hi all,

We also have a Projecta 2000w intelliwave Inverter (and 400ah of Lithium batteries).

It is now 9 yrs old, is hard wired into the whole caravan system (except for the battery charger) and selectable by switch when off grid.

It will power, one at a time, (and has done for those 9 years) the Aircommand Ibis 2 air con (for up to 2.5 hours), 1200w microwave, 1800w kettle, Suburban 22l hot water system and every other electrical appliance in the cvan.

It will also operate at 2400w, without damaging itself, for up to 4 minutes. Handy for high start up power and has a 4000w surge capacity for a very short time.

It comes standard with a fully functioning (wired) remote panel that can be located up to 5 metres from the inverter. Handy if you cant locate the inverter in an accessible spot.

Whilst it is obviously preferable to have the inverter close to the batteries, this is not always possible.

Ours is located 6.5 metres from the batteries (so 13 metre return run) but has 00awg cable.

I have no association with Projecta, just a happy camper and believe this model inverter is very good value.

Regards,

Ian

valiant81 · Guru

Hi Rob; With inverters one has to look at the load that you with to use on it in watts. A pure sine wave output is also a must!!. A inverter that can also double as the battery charger for you caravan batteries is a good idea and also saves having a stand alone battery charger wired to you house batteries. The newer type of inverters ( have a good look at Victron inverters, there are others out there also ) will also switch between mains power and the power generated by the inverter, so one box does the lot and can be hard wired into your caravan and all of the 240 volt power would work as well as if you were on mains power. Charges you caravan batteries when on mains power, auto or manual switch over, some even have a solar input as well.

The size of the inverter and the and battery capacity, solar input. While AGM batteries are still the norm there weight is a problem. One of the buses that i did had 8 X 220 AGM batteries and the combined weight was just on 520 Kg's and a 3Kv inverter charger. The A/C was either mains powered and a separate mains input to the buses own mains input or a small 7.5 Kw diesel generator , Lithium batteries are starting to be the more common approach for portable use ( caravan and mobile homes ) the weight of a Lithium battery is also a lot less than AGM batteries. Next is the cost and a 2kw inverter/ charger is around $2000. So a dollar a watt.

Running A/C from a inverter would be a big ask on batteries and inverter. It can be done but the size of batteries in AH, Voltage is also a question and with the big systems ( households ) 48 Volts is the new voltage as the current draw of a large inverter is huge and why on larger systems the higher voltage is used as well as several large inverters.

-- Edited by valiant81 on Sunday 7th of November 2021 10:15:09 AM

Whenarewethere · Guru

Also the Victron inverters state in their data sheet how much they de-rate every degree above 25°C.

With a lot of "no name" manufacturers these sort of important details disappear into obscurity.

Heavy load, not mounted for clear air flow, stinking hot day, & one wonders why their inverter overloads.

Whenarewethere · Guru

2400 watts/12 volts = 200 amps, with 6.5 metres (13 metres + & - ) recommended cable size.

nomadz · Veteran Member

Hi Whenarewethere,

Are you able to send a link for the voltage drop table you provided. It would be a handy tool to have.

In my setup, the 2400w is what the inverter will power for up to 4 minutes.

It is not what we draw from it.

I think the air con (our highest draw appliance) draws about 140 amps (1680w) on start up and a bit less when the compressor is cycling.

Using the table you provided, the 00 awg cable is more than adequate for our requirements, and has proven to be so over the past 9 yrs.

Dont get me wrong, we do not regularly run the air con off the inverter and when we do, it is normally only for an hour or so if pulled over for lunch in summer. Turn it on about 10 mins before stopping and cvan is nice and cool for lunch.

The one time it ran off the inverter for the 2.5 hours was when it was left on in error, but nice to know the capacity is there!

The microwave and kettle are used regularly but only for a few minutes at a time. The hot water is used when driving as the dcdc and solar bring the batteries up to 90 plus % by lunchtime so why waste the free energy.

Regards,

Ian

Aus-Kiwi · Guru

Its easier to push 240v through 2.5 mm wire than 12v DC ! So as said, close to battery as possible . Youll save heaps on purchasing right sized cable .

Whenarewethere · Guru

nomadz wrote:
Hi Whenarewethere,
Are you able to send a link for the voltage drop table you provided.

This calculator I downloaded with Safari years ago, haven't seen it since, & sits on my computer somewhere & opens with Safari. There are plenty of calculators.

Mamil · Senior Member

nomadz wrote:
Hi Whenarewethere,
Are you able to send a link for the voltage drop table you provided. It would be a handy tool to have.

Hi Nomadz,

I find it useful to use the equation for voltage drop rather than rely on tables/calculators as it gives a better insight into what and how various factors influence the end result:-

(L x I x O.0172) / A

Where:-

L = length of circuit in metres (include both positive and negative)

I = current in Amps

A = cross section of cable in mm2

0.0172 is the constant for the resistance of copper wire in micro Ohms per metre

nomadz · Veteran Member

Gday RobDor,

if you havent made your decision regarding the inverter, some real world operations may be of interest.

We are currently assisting with the harvest operations and our caravan is used as the tucker truck.

The caravan is normally parked in full sun and in rather dusty and dirty conditions,

The Honda 2 powers the air con from approx 10 am to 10 pm and daily temps, while unseasonably mild at the moment, are in the low to mid 30s and soon to go much higher.

We can operate our Projecta 2000w inverter at the same time as the Honda is powering the air con and Projecta battery charger (albeit at a reduced rate of 6 amps)

The inverter, which is turned on about 7.30am and remains on until 10.30 - 11 pm, would be used to boil/reheat a 1litre 1500w kettle at least 6-8 times a day, as well as the 1400w microwave at least 4-6 times a day and toaster/sandwich press as required.

It has been doing this every year for the past 9 years so has proved itself in very harsh conditions.

Not saying that other brands would not do the same, but this is real world operating conditions.

Regards,

Ian

valiant81 · Guru

Hi all; One thing that i forgot to write in my last answer to this post is that with some of the inverters on the market ( Victron for instance, but there are others out there ! ). Is that the 240 volts mains input is connected to the inverter and while connected to the mains supply feeds the mains to all of the power points connected to your inverter.
This as well while one mains supply will also charge your house batteries at the same time. When the power is disconnected the inverter will switch over to the inverter mode automatically and run your 240 volt equipment as normal. No switches to play with and once the main power is connected back up the inverter will switch back and start recharging your house batteries.
These inverters/chargers can be remoted so as to turn the unit off completely, say when you are traveling with a caravan. One box does the lot. Of course these units have to be installed by a qualified electrician. These units can also be daisy chained for bigger systems.

Not cheap but worth having a look at!!

-- Edited by valiant81 on Wednesday 8th of December 2021 10:05:46 PM