Pure sine wave inverter

Hi Wayne,
I bought a Honda 650W, 20+ years ago and it served the purpose up until 2 years ago when I sold it too a mate for 4 blocks of beer.
It is still running and apart from regular oil and spark plugs it has never missed a beat, well probably wouldn't have known because it runs so quiet.
Know of people who have bought the cheap Chinese 2 stroke and rued the day.
Here you go only 10 years old, $200.00.
From memory the output was 300W if you were also using the 12V charging facility at same time. Ran for 5 1/2 hour on about 1 1/2 litres of petrol.

http://www.ebay.com.au/itm/HONDA-EM-650-GENERATOR-/281037848929?pt=AU_Hardware&hash=item416f294161

Peter

Hi nightjar, I am normally the king of secondhand stuff but on this occasion I have decided I will buy myself a nice new b**tard that will in all hope see me through my camping days as well as the fact that I live in a cyclone area, it looks as if in all likelyhood a Honda20I will be my best bet, coupled with batts and maybe some solar... yet to be decided. good thread!

Wayne.

Digginerup wrote:Very interesting thread, especially to someone like me that's in the throws of tackling camp power production, I see the Honda 20I gets a good wrap, I have seen them working first hand and they seem to be brilliant and so quiet!!! are there any of the cheaper models worthwhile that people have had experience with?, I'm not expecting to get a Honda for the price of a lesser known name, just curious as to how they stack up.. if at all? what would the expected life hours of a Honda20I or similar machine be?, if that's known?.

Wayne.

I don't think there is much between the Honda and the Yamaha ,I witnessed a Kulkyne 2kva recently and it was in my opinion just as quiet , Yamaha motor with yum cha bits assembled in Mildura

With Michael's (Boobook) permission have copied and pasted detailed information he has written.

Boobook quoted;
A beautiful sunny day here, so the test is under way.
Set up solar panel, 6.65a. @ 14.6v. going into battery.
Checked the Engel draw on 12v. - 2.65a.

Connected 300w. inverter to terminal block with 0-20amp, ammeter in series.
Turned fridge off, switched inverter on, initial kick then showing maybe 0.2 amp. Switch fridge on, ammeter showing 3.9amp.

Switched system off and replaced 0-20 ammeter with digital 0-10 (TES2360LCR commercial multimeter) Corrected current at inverter 3.85a, so was close enough.

The volt meter on the solar input (part of system) now fluctuating between 12.75-13.75 as it does when the battery is well charged. (inbuilt regulator)
Switching 240v. lights on in the van gave a commensurate increase in current draw at the inverter showing all was working as intended.

Conclusion here is that the fridge when connected to the battery draws 2.65amp., on 240v. through inverter 3.85amp. (at nom. 12v.)
The increase (1.2amp.) could mean an addition of around 16 amp/hrs/day or more than 30%.
It may also mean that the fridge has a higher energy requirement on 240v.ac than 12v. dc?

In reflection I should have also considered that my inverter is only around 75% efficient. It is one of the older generation and quite cheap then so maybe the newer ones much improved.
However it does prove that in the series chain of things some power (watts, amps, are sacrificed and lost)
When I connected the inverter through the ammeter yesterday it showed no current draw until I switched it on at the inverter. It "kicked" the needle then showed what looked like 0.2a. Not until I switched the fridge on did it show the current draw noted. Possibly a nominal milliamp amount when connected but switched off.
Michael (Boobook)

Thanks for that info. Don't forget though Peter that those figure are for a Engel 2-way fridge with a 2.65A draw and it cycles on and off, so it's only on 50% of the time approx. 3-way fridges have a much higher draw when working on 12V as they are not thermostatically controlled on the 12V source and stay on continuously (at least mine does anyway).

Yes Con,
This info explains that using an inverter draws more power than running direct 12V, something I wasn't and maybe others weren't familiar before info started rolling out in this thread.

Cheers
Peter

Yes nightjar it's the old saying " ya get nothing for nothing"

Thanks Nightjar, appreciated.

I could also add that I recently purchased the 120w. folding solar panel so that during next years trip I an hoping the van battery can be maintained when not connected to the 2 aux. batteries in the truck.

From this short trial I can assume that with around 7hrs. of sun I will replace ~40a.hrs. of charge back into the battery. During that time the Engel fridge will require ~9a.hrs.
This provides a surplus of ~30a.hrs., but because it requires more than 30a.hrs. input to get 30a.hrs. output from a battery, the net gain would be ~20a.hrs. (say70%).

With the fridge and lighting requiring ~(35-9 net), 26a.hrs./day, indicates that with the 20a.hrs. available as surplus input from the solar panel, the system is almost at break even point.

More testing will now be undertaken to determine the validity of the proposed system in terms of the existing.

The truck setup has a 60l.Trailblazer on freeze, 2x100a.hr. batteries with the present charging by (a) vehicle alternator to all aux. batteries through a marine solenoid, (b) Honda eu20i, 240v. 20a. 3 stage charger with metering plus for the van 1x100ahr. battery with 240v. 15a. 3 stage charger.
Michael

Where did you purchase the folding solar panels ? eBay or? Brand ?

There's an old saying with solar......work out what you need, and double it.
In a perfect world you can predict the sunlight hrs, we dont belong to such a world unfortunately.

Fridges are on more times than off, the engel with its swing motor uses the same at start up as it does when running, the danfos motor uses considerably more at start up than when its running.....i have both engal and weaco fridges and wont buy another weaco again for this reason.
The 40L angel is on 24/7/365 as a freezer, running at around -3-7pending ambient temps. Some will say thats not cold enough to freeze meat safely...like a supermarket, i dont intend keeping the meat for very long and can tell you at that temp its frozen enough to use as a hammer for the time i intend keeping it. Others turn the fridge up to much lower temps.....thats fine by me. Your meat is not frozen when you buy it, and what becomes of it a day after its not sold.??? Its marked down and becomes a Special.

Ark.
Purchased from Electus Distributions, Victoria Rd. Sydney.
mike

boobook wrote:Ark.
Purchased from Electus Distributions, Victoria Rd. Sydney.
mike

Thanks for that

Gday Peter and All
Don't know if it's any help but here's what I'm running in the van.
2x100ah AC Delco's
1000W Inverter
Dedicated double power point for Inverter that is coupled through an RCD
100W solar panels
The bride has been taking her overlocker, sewing machine, laptop, rice cooker etc with us each trip and there are no issues about running out of power. The gear is all new but we do run our fridge in the caravan on gas, as I reckon it is so convenient, cheap and pretty fail-safe.
We generally return home with as much juice in the batteries as when we left.
cheers
Brett

Hi Brett,
Dedicated double power point for Inverter that is coupled through an RCD
Who did the wiring for you, or a mud map would be handy?

Some interesting information here on this site, particually info about charging the van batteries;

http://www.fridge-and-solar.net/index.htm

Peter

More info here.
http://www.windsun.com/Batteries/Battery_FAQ.htm#Charge%20controllers

Gday Peter
Here's a couple of snaps of the rcd setup. Dead simple to wire up. I bought the power point from an online caravan part joint, all up about $50.
cheers
Brett
[img][/img]
[img][/img]

Hi Folks,
Regarding dedicated 240V inverter power points.
When our van was being built I had the sparkies install two double power points on the RHS of the van, one on top of the fridge and another under the table.
These were terminated in a junction box in the front boot alongside the power point for the battery charger.
After taking delivery of the van I connected a suitable 240V cable terminated with a three pin plug and installed a double power point to replace the single one for the battery charger.
A 700 watt pure signwave inverter was also installed along with a remote switch inside the van; don't have to go outside on wet or freezing days/nights to turn the inverter on or off; handy.
The concept is that when on mains or generator power the wander lead from the two dedicated power points is plugged into the spare 240V outlet alongside the battery charger which in turn connects them through the earth leakage safety devices.
When bush camping the wander lead is removed from the 240V power point and simply plugged into the 700W inverter, this supplies sufficient power to run all of our low wattage devices from four power points in two locations when required.
Hope the above may be of help to anyone planing a new rig or modifying an existing one.
Cheers, AUoptimist.

Gday AU
Someone who knows suggested that they could make me up a "suicide" lead (male both ends) that ran from the inverter powerpoint back into a 240 powerpoint in the van and then we could run everything from there. Decided against doing that and have found that the double inverter power point does the job nicely.
cheers
Brett

Smart thinking Brett,
Apart from the lethal danger of doing something like this, if you inadvertently plugged your standard lead into the van input plug, your inverter and maybe your van would disappear in a cloud of smoke.
Appears you already knew that any way.
About as dangerous as plugging your generator into a house socket during a power failure.

Peter

Thanks fo all who contributed.
With information received here and about it is now futile to proceed with my original plan. Rather than shelling out for extra panels it will be a simpler and cheaper option to travel with fridge on 12V with battery charged by vehicle alternator and swap to gas when camped. The solar panels currently installed will be ample for running caravan.
We can never stop learning if we listen.
Cheers
Peter

Please correct me if I'm barking up the wrong tree but why would you invert 12v to 240 v to run a engel or a Waco as it would be converted back to 12 v at the fridge ?

....if you inadvertently plugged your standard lead into the van input plug, your inverter and maybe your van would disappear in a cloud of smoke....

what??

The std plug (inlet) that allows you to run your van on normal 240v mains ...is a Male15A .
The std (inlet) on your inverter, is female....so from the inverter to the std van inlet plug (male)...you cant go wrong.
If you pull up at a park, and for some strange reason your inverter is still connected...you would have to remove one end of the lead... either the inverter end..or van inlet, in order to run from mains 240v. If you were to plug your inverter into the vans outlet...you may have problems. Why would anyone make a lead with 2x males plugs when a stock lead is all thats needed to run the van off an inverter.??

Just recently, my aircon failed...kept throwing the RCD when connected to mains 240v....yet the van including the aircon, functioned normally on the inverter generator. It just wouldn't function on mains 240v.
Replaced RCD yet was not the fault....my failure to disconnect each 240v appliance in the van from the wall sockets to isolate the problem appliance...cost me a new RCD that i didnt need....bugga!!
When fault finding earth leakage....turning the power-point off wont help find the fault...the switch does not turn off the earth. You must unplug.!!

What is an RCD and how does it work?

An RCD is a safety device that monitors electrical current flowing within a circuit from the meter box or distribution board. It works on the principle that the electricity current flowing in must be equal to the current flowing out of the circuit.

If the RCD detects an imbalance in the electrical current, indicating a leakage to earth, e.g. current flows through someone’s body to earth, the RCD immediately cuts the electricity supply to prevent electrocution.

RCDs are extremely sensitive, disconnecting within 10 to 50 milliseconds of detecting a leakage current. This is usually set at 30 milliamps for homes but may be less in other situations, such as hospitals.




Is an RCD the same as a circuit breaker?

No. Many homes already have circuit breakers installed. However, circuit breakers only protect against overloading and short circuits. They do not prevent electrocution.

....if you inadvertently plugged your standard lead into the van input plug, your inverter and maybe your van would disappear in a cloud of smoke....

What I was referring too here was about someone who not once but twice fused inverters (costly) by running a suicide lead (two male plugs) from his inverter and plugging it into a 240V socket in the boot of his van.
Forgetting to unplug the inverter he connected his van up to home 240V using the standard 15A male input plug. Poof!!!! two inverters ruined.

On a different note, have now successfully trialed our bread maker in the van using the 2500W inverter. Set machine to commence at 0230hrs and crusty loaf baked ready at 0630hrs. 12.8V still available in batteries after the bake.
This will enable us to have fresh bread during our couple of month trips this year, gaining valuable freezer space usually taken up by loaves of bread.

Cheers
Peter

Ark wrote:Please correct me if I'm barking up the wrong tree but why would you invert 12v to 240 v to run a engel or a Waco as it would be converted back to 12 v at the fridge ?

Have now, thanks to info from here on the forum, established that info supplied earlier to me from another source, that it is more efficient to run your van fridge on 240V via inverter is incorrect.

Fridge on 12V while travelling, on gas when stationary.

Cheers
Peter

Ahh ok thanks !

Peter, im glad thats sorted.

Bread maker on the inverter is still asking a lot from your batteries tho...thats a heating element. Regardless of the AC Amps...its still going to be a fair amount on DC.


RCDs
Some questions need to be asked in regards to earth leakage when using inverters and inverter generators.??

From what iv read and now experienced....generator electricity plugged into a caravan is not protected by the vans RCD. Possibly the same for inverters.
Both generator and inverter are isolated, and while ever they remain isolated we should be safe.....however thats hard to swallow and correction is welcomed.
Modified sign wave inverters may also have problems with safety issues being mostly 220-230v....this may impact the trip functioning of the RCD.???

Anyone qualified to go there.??

I think the explanation of how an RCD works written above was correct but left a little short. Current through active/neutral varies all the time, the only way an RCD picks up even the slightest of imbalance is in respect to earth.


From: http://www.victesters.com/what_is_an_rcd.htm
How does an RCD work?

An RCD monitors the current flow in the active and neutral wires of the power lead or device connected to it, all the time looking for an imbalance or difference in the currents in each wire.

The undesirable current imbalance in the active and neutral wires occurs when current flows to earth.

Earth leakage safety switches work on the principle that current going into a device should equal the current exiting the device and that any difference between the two is due to current flow via an unwanted or undesirable path.

With a generator and invertor, the problem exists if the power source is not earthed, therefore an rcd cannot function.

From: http://www.ata.org.au/forums/topic/1445

"An RCD won't work if not earthed, it is designed to detect leakage to earth and can't do that if there's no earth connection..."

Almost correct. An RCD is designed to detect an inbalance between the two line conductors. A stand alone electrical installation without earth can function perfectly well (with an RCD operable)with no reference to earth at all (and this is perfectly safe, legal and is regularly done in the marine and RV industries but other requirements are also required).

What Lance is really saying, is that most inverters require a modification to enable the RCD (safety switch) to operate. The inverters are safest as a single point non-earthed unit, however as soon as you plug in the power board, you loose that benefit. Australian standards differ when the earthing of inverters are addressed. At least one allows a "free for all" approach and at least one other requires fault monitoring (about $700) when used with a "bonded" earth (your power board for example, with no modification to the inverter).

For me, all my inverters are modified so the safety switch does work and that is my advice in the majority of cases (including your case). To suit all standards, the safety switch must be permanently fitted to the modified inverter, rather than using the "plug in" type.


The undesirable current path may be via a person or an internal fault in an appliance or tool. The imbalance may also occur by cutting the power cable or by using tools or appliances in unsafe wet or damp areas. All electrical equipment will have some amount of current flow via earth (earth leakage). It may be minute (< 100 micro Amps); but it must be less than the limits specified in the AS/NZ 3760 standard (1.0 mA for Class II double insulated equipment or 5.0 mA for Class I or earthed appliances).

12.8V still available in batteries after the bake.

Hmmm? that voltage indicates 100% SOC still.
Is this during the day while the panels are working, or while the battery/s are being charged by a geny at night.??

Narrawa,
Have been baking the bread at home,(the 5th loaf tonight) trialing different amounts of ingredients to perfect it before heading bush for a month.
I set the bread maker to start the cycle at 0230 and it finishes at 0630.
The only top up the two 110AH AGMs are getting is from two panels (140W) through a Morning Star regulator, by 10am they are in float mode..

That would explain the 12.8v.