Skip to main content ↑ ↓
Topic: Inverter Question (Read 1915 times) previous topic - next topic

Re: Inverter Question

Reply #20 –
I use a slightly larger one because it also supplies the awning motors with power when necessary.
Xantrex prowatt 1000 watt. It used less than 800 milliamps [less than 10 watts] in idle mode.

Re: Inverter Question

Reply #21 –
As I looked at the charts posted earlier the Victron inverters appear to have peak efficiencies as they approach their mid point in power output.  I am typically running mine at about 1/3 continuous rated output.  It seems like a good fit.  They now have a 1200 VA model.  Uses about 1/2 watt more at idle and is 91% max efficiency. 

The circuit powered by my smaller inverter can be switched to the big inverter or the landline/generator.  While you are in there making it happen you might as well give yourself options.

Re: Inverter Question

Reply #22 –
Roger you have a specific efficiency chart for your units?.  Do tell.

Re: Inverter Question

Reply #24 –
Outback, xantrex, and Victron do not seem to  publish efficiency charts specific to 12 volt units.

The one chart I can find is Magnums.  Overlaid over their similar max efficiently charts at 24/48 volts sane as the  Victrons.

In other words xantrex and outback publish no charts.  Max efficiency only. 

Outback quotes max only.  And Victron only has charts published for their 24/48 volts units that show a similar efficiency curve as the magnum.

Magnum has the only published chart available.

And that chart shows a sharp drop off at higher levels.

So I am supposed to assume that Victron  units are superior to the only other unit with published charts in the voltages we use.

Yet their 24/48 volt units are very similar.

All the big boys use 24 volt systems and 24 volt components in their conversions and/or  use a Vanner step down transformer to end up with 12 volts.  The Vanner consumes power also to reduce the power.

I need a seemingly non available chart to back up the idea that a 12 volt Victron of any size is much more efficient than any other.

At this point the verified max efficiency based on the charts is a 24 volt Victron 11 with a single toroidal transformer.

95% at low to mid outputs.  You would need a step down.

The busses have run this setup forever..

Anything else but the magnum is unverified.

The idea that Victron says they have no charts is an eye opener.

I can post the emails so you can ask yourselves but I think the other brands are all similar in 12 volts.

90% with large heat sinks and dual variable speed cooling fans.

93 and 94% with a smaller transformer and a single cooling fan.

Max.

 

Re: Inverter Question

Reply #25 –
I think you (Bob) posted an efficiency chart for a 24 volt Victron.  Since the deaigns are the same for 12, 24 and 48 volt units there is little reason to think a 12v would be significantly different from a 24v.  Whether it is a Phoenix or a MultiPlus 12, 24 or 48 volts output or 120 or 240 volt input the differences are only a percent or two between them all.

The current Victron 3000VA Multiplus has a max inverter efficiency of 92 and charger efficiency of 94% and used only 9 watts at no load.

Bob, I am not sure having specific efficiency charts over the entire output range is particularly important, interesting ... yes.  Your inverter is going to be operating at a wide range of outputs over the day.  Most of the time it is going to be at a pretty low level and then you make toast.

I think the real world user want to know how much power does it use to be on, what is the maximum continuous power output and what are peak levels.

I have used our Victron inverters from -30° with no basement heating from the Aqua Hot to driving across North Dakota at 116°.  We have never had any issue with either of them.

I looked at the control panel this morning.  The Multiplus has a high internal temp alarm and a high battery temperature alarm.  And the Victron BMV 702 reports alarms for both high and low battery temperatures.  Since virtually everything is use configurable these probably can be set as you want.  If you have internet access all of the operating parameters for both inverters, the charger, the BMVs (I have 2j and the solar charge controller are uploaded at a user specified interval and can be monitored or reviewed from anywhere.  The integration of the Victron equipment was a big part of my decision to go this way.

If you can push a button on your generator start panel to start the generator then the Multiplus, the Battery Monitors or the control panel will start your generator based on voltage or state of charge that you specify and then shut it off at a voltage or SOC you specify or at a minimum time you specify,

Several good choices out there based on specific needs.  It is worth looking at all of them to get a best fit for you.

Re: Inverter Question

Reply #26 –
I would expect a 24V inverter to be slightly more efficient than a 12V inverter simply because of the higher input voltage. The same design should
have similar efficiency curve shapes regardless of input voltages and so any curve for the 12V unit would probably look much like the curve for the 24V unit.

Re: Inverter Question

Reply #27 –
Sounds great.  My point was that the Magnum with a similar unit in 24 volts to its 12volt unit show show a lot of efficiency differences in its 12 volt unit versus its 24 volt units.

And that outback and xantrex post no charts at all just a max efficiency number.

The spec sheet for a Victron shows max efficiency at 93%.  Then the 24 volt chart shows over 95% at one point.

The xantrex, outback and magnum 12 volt units all show 90% max with their much  larger heat sinks and dual cooling fans.

So I would think they all have the same efficiency roll off as their output increases.

With an alarm the unit obviously has a program to monitor its internal temps at the transformer and the mosfets.

Why not show the numbers like Magnum does?  Idiot lights versus gauges.

No specific labeled 12 volt chart.  No readout of specific internal temps.  Marine design. Smaller transformer, single cooling fan.

Beautifully designed unit for its exact use.

I doubt if it's capable of running a roof air in the summer desert if a ultimate emergency occurred off the alternator.

The bluebirds I sold 30 years ago could  do that.

I baked a dinner in our coaches convection microwave crossing the desert at 110 degrees off the alternator after its rebuild just to verify the system's condition and capacity.

Voltmeter jumped around a bit as the load went on and off but it worked fine.

Pretty sure a Victron would derate and turn off.  Someone want to test theirs like I tested ours?

The idea of a smaller inverter using less power is opposite from the industries  published efficiency info.

Over time I may get around to adding a Victron just for the gee whizzes as an alternative.  But would not remove the higher heat capacity Magnum unit.

Or a 24 volt system with a step down like the big boys do.

Would appreciate someone actually loading a Victron up with a large load and a high temp for a long drive just to see.

Good test anyway.  Nothing would be damaged.  Just shuts off.

For sure I would test it myself.  A bad battery and/or connection in the coaches system could call on the charger to output large amounts of current for a long time.

Same as a large inverter load at high temps for a long time.

surmises are great.  Only way to actually know is to test it.



Re: Inverter Question

Reply #28 –
Bob why don't you hook up you magnum to your air conditioner and run it that way for a while?
You can then post your numbers and efficiencies, and we all can use you as a baseline to test our own equipment.

Re: Inverter Question

Reply #29 –
Quote from: jcus –
Bob why don't you hook up you magnum to your air conditioner and run it that way for a while?
You can then post your numbers and efficiencies, and we all can use you as a baseline to test our own equipment.

Great idea!

Bob--I really appreciate your enthusiasm on this subject, but it's possible to overthink things! Given the reasonable cost of smaller Victron inverters and your positive rxperience with Samsung refrigerators why not take the plunge and install one of each and the carefully document your experiences?

Re: Inverter Question

Reply #30 –
You guys have modded the coach from what Foretravel and the rest of the nice motorhome industry produces.

No testing to see what limits you may have changed.

Don't need a roof air rewrite to test.

Two crock pots plugged in on the counter and turned on high full of water would be a good start.

Inverter only.

This is 101 stuff.

I envision a emergency use where the gen is too low of fuel to run and then having the option to start the engine and fast idle it to furnish 12 volt to the batteries then have the inverter convert the 12 to 110 and run a high load like two house refers.

That's the way Foretravel shipped it on purpose.

What if the coach was not a toy.  What if you really needed it? 

To not test it to understand its functionality is crazy.

Same with heat strips. They work at zero degrees just fine.  Heat pumps do not.

The star coach bus conversion has heat strips.

In our case in shaky town I need to absolutely KNOW what any system we have will actually do before we need it.

Not a toy.  Serious use.

Birds could run the wrapped plumbing lines throughout the coach on 110 volt and a separate 12volt system.

The 110 could run off the inverter.

They also had the tanks heated and heat plates on the coaches battery banks

Like I said what if it's not a toy.

Like the winter live in U320 in Montana?  They put block foam around the coaches underside.

1/2 tank of diesel fuel for the aquahot parked All winter.  Block foamed the windshield area if memory serves me.

I purchased a expensive li-ion battery bank/1800 watt inverter/solar panel setup  that has a 20 amp Anderson connector out put plug in front.  Guess what. Only puts out 10 amps.  Will not run a small rv water pump setup.

Two units tied together stated a pump and disconnecting one and the running pump continued running with no load.

Would not restart on one unit.

So I ordered two 25amp at 14.1 volt output each power supplies with a Anderson connector on the front and will power my pumps of the 110 invertered side.

To have actually needed this to work and find out it does not work could be deadly serious.

One pump  setup I have has a 2 gallon pressure tank on it.

Could hook up to the coach to run its plumbing system externally or to refill  the coach as we have no gravity fill.

Plus I have a macerator pump that is also 12 volt that attaches to the Valterra end of the coaches drain pipe and can pump waste out through a 5/8 Th inch hose.

It needs 12 volt and around 50 psi water to work.

Bought 2 of the adjustable pressure controllers.  Nice units

I kept our superduty 4x4 long bed truck for emergency and fun use.

Can move water in aqua tanks in the bed to refill the coach and/or furnish water to our home.

If you live here you will not be able to get out of la after a large quake.

So you better plan on how to live here with no water or power.

Having a Foretravel within walking distance is a big advantage.

We are wiring the house to run off the coaches gen.

Can park it across my driveway and the gen would be next to the electrical service entry and fuse box.

Plus can level the coach there.

Mid door is in driveway. 

Found a Frenched drain I can hook into to dump wastes into.

We have an association pool I could tap into for water and the pumps and tanks in the truck to move water.

Our garage door Has a battery backup for the opener.

The rv storage lot has a battery backup for it gate. If the battery fails the opening system fails unlocked.  Slide it open by hand.

Or use the truck to pull the gate open or drive through it.

You never know. As a little kid I went through a 8 earthquake 100 miles away from us.

You would never forget that if it had happened to you.

Threw me out of bed and I woke up halfway to the floor shake. Could not walk in the house. Stayed on the floor.

Burned into my memory. I  Can vividly still relive it and I was 5.

Re: Inverter Question

Reply #31 –
Bob, as usual I don't understand much of what you say, but if you are willing to hook up two crock pots and test them on your inverter and post results, I will do the same on mine and we can compare numbers.

Re: Inverter Question

Reply #32 –
Good start.  Then we can add a third then try this in warm then hot conditions.

The owners group here has never posted a noticeable inverter derate or shutdown as far as I have read and I read every post back to the old group.

Foretravel added a external Orange blower fan pointed into their heavier transformer inverters I assume for a reason not just to look at.

If you were in a boat and moving the bilge fan is required to be on.  Nice cool  air in a white Fiberglass hull away from the motor.

Way different use. 

Road temp in Arizona can exceed 140F. 

With the Magnums internal temp readouts you can act to prevent derating/shutdown in advance.  Open a compartment door?.  Add a fan?  Park in the shade?.   

Re: Inverter Question

Reply #33 –
I have never seen any temperature alarms on my Victron equipment.  If they are like any other alarm notification they show up with specific numbers.

Disorganized over-analysis of disconnected facts will likely never lead to any conclusion, just more confusion and threads leaving nowhere.  What exactly are you trying to accomplish?  Specifics.  How do you assign value and how much to accomplishing each of them?  What solutions are there that start to meet those goals?  Does one meet more of your higher value goals?  No solution will be perfect but one will be better than the others.  If you need a solution sooner than later then you have to find a best fit to your specific needs.

Re: Inverter Question

Reply #34 –
Roger,

How does this sound? When I install my new inverter, I will check on the idle wattage, the wattage used when the microwave is heating a pint of water and then a resistance heater plugged into an outlet all with known current draws. This way, I can check wattage and efficiency for both. I understand that inverter manufacturers fudge a lot on idle wattage and efficiency.

They are both 1500 watt inverters, one OEM Heart with a modified square wave, the other is a MIC (made in China) sine wave.

For readers who may want to use their multimeters to check the idle wattage, the inverters have capacitors that will draw quite a bit for a second or two and that will fry a multimeter at the ten amp setting. You need a shunt to do the measurement.

Suggestions?

Pierce

Re: Inverter Question

Reply #35 –
The Victron alarm is a light.  No numbers. No numbers in between shown.  Light on. Next step is shutdown.  In between it derated it's output

The Pheonix inverters are small transistor units with no graph either just max efficiency somewhere.

Here is part of the technical paper for the 24 and 48 volt units:


In general the toroidal transformer is the limiting factor in our inverters and inverter/chargers, while semiconductors are the limiting factor in our battery chargers. This explains the difference between the curves shown in paragraph 1 and paragraph 2.
Knowing that, in case of forced cooling, the cooling capacity of a heatsink or transformer is proportional to the temperature difference between the heatsink/transformer and the cooling air flow, formula (2) can be restated as follows: 

Only derates from internal temps without a readout and unlike the Magnum does not factor in battery temp which is also shown in numbers on the led screen.

A Bluetooth link needs power on both ends as does the computer chip that calculates the figures shown on a Victron screen as does the color screen.

All other inverters run a wire and use a transparent remote screen that the numbers show on in unlit black leds.  And have a "power save" program to turn the backlight off of their remote panel.

Would you think dual ended Bluetooth  connections and a color screen  consume at least an amp of 12 volt?  That was the idle difference between the units as far as I see. 20  vs 32.

Here is the end from Victron:

where Iout is the output current; K is a constant; Tmax is the maximum heatsink or transformer temperature; ΔTo is the temperature rise of the heatsink or transformer due to the no-load power dissipation; and Tamb is the temperature of the cooling air flow.
Formula (7) shows that when ΔTo + Tamb = Tmax, Iout = 0.
In words: when the ambient temperature is so high that the no load power dissipation alone will cause the heatsink or transformer to reach the maximum temperature limit, the output current of the circuit is 0. Any output current would increase temperature beyond the maximum and result in shut down of the circuit due to overheating.
The derating formula (7) is applicable when the ambient temperature increases beyond the temperature at which the full output power is specified, in general 25oC (77oF) for inverters and 40oC (104oF) for battery chargers.
Why 25°C (77°F) for inverters? Inverters are very often used with intermittent loads. Short term power and peak power are therefore more important than the continuous rated power. Battery chargers on the contrary will regularly operate at maximum output current for several hours and are therefore rated for continuous operation at 40°C (104°F).


Re: Inverter Question

Reply #36 –
Ran the ac off the multi plus on the batteries several times.. Ran both actually... it shut down with both compressors kicking on at the same time.. over 4000 watts... My ac runs at 2200 watts when compressor is on and whatever else I have running (lights and such)..

It will shut down and reboot if it is asked for to many watts

Re: Inverter Question

Reply #37 –
Quote from: Caflashbob –
The Victron alarm is a light.  No numbers. No numbers in between shown.  Light on. Next step is shutdown.  In between it derated it's output

The Pheonix inverters are small transistor units with no graph either just max efficiency somewhere.

Here is part of the technical paper for the 24 and 48 volt units:


In general the toroidal transformer is the limiting factor in our inverters and inverter/chargers, while semiconductors are the limiting factor in our battery chargers. This explains the difference between the curves shown in paragraph 1 and paragraph 2.
Knowing that, in case of forced cooling, the cooling capacity of a heatsink or transformer is proportional to the temperature difference between the heatsink/transformer and the cooling air flow, formula (2) can be restated as follows: 

Only derates from internal temps without a readout and unlike the Magnum does not factor in battery temp which is also shown in numbers on the led screen.

A Bluetooth link needs power on both ends as does the computer chip that calculates the figures shown on a Victron screen as does the color screen.

All other inverters run a wire and use a transparent remote screen that the numbers show on in unlit black leds.  And have a "power save" program to turn the backlight off of their remote panel.

Would you think dual ended Bluetooth  connections and a color screen  consume at least an amp of 12 volt?  That was the idle difference between the units as far as I see. 20  vs 32.



Bob, as my mother used to say "you are straining at the nats, and missing the camels"
If you are so worried about a couple watts here, and a couple of watts there, you are living way too close to the edge. Just bite the bullet and upgrade your solar and batteries, and you will not have to worry about these things anymore.

Re: Inverter Question

Reply #38 –
We are desert rats.  Countless days at the Colorado river with watercraft.  110-120 most days.  Li-ion is not certified past 104.

We are winter users,  countless days in the mountains down to minus 30F. In coaches. Li-ion will not work at those temps.

Ok  bring them inside.  Fire hazard.  Cannot ship on planes.

Was in the burn ward.

Solar for sure. 

Just trying to verify the advantages of the various equipment being used here by some.

Temp and load restricted batteries and appliances so far have not seen to be a advantage. 

Exactly the reverse.

Here is Holland's answer to a chart

Unfortunately not, check for more details with a Victron dealer in your area is my advice.


With best regards,

Jan Klumpenaar
Sales Manager
Victron Energy BV
Phone:+31365359700
Mobile:+31653115367
Skype:janklumpenaarvictronenergy
jklumpenaar@victronenergy.com
Victron Energy

Join the professionals:  Victron Energy - Victron Professional


-----Original Message-----
From: Robert Hulka [mailto
Sent: Saturday, July 27, 2019 9:30 PM
To: Victronenergy sales <sales@victronenergy.com>
Subject: Re: Efficiency chart?

The 12 volt and 24 volt show 93% and 94% max efficiency yet you say they are the same.  Do you have a specific 12 volt chart?

Re: Inverter Question

Reply #39 –
Well Bob, you are wrong about Victron alarm notifications.  They show up on my Victron Color Control GX as an audible alarm and a notification with specifics values.  The Victron BMVs also show alarm values and an audible alarm.

You are quoting lots of disconnected "facts" trying to make a point that is very hard for any of us to see.  If you don't want to use a Victron product then don't.  Your mostly difficult to decipher arguments aren't going to convince anyone who has already decided on Victron or will choose it because it works for them.

"Perfection is the enemy of good". In your obsession with this subject your most feared event will come to pass and you will be no closer to be whatever you think is "ready".  Choose and do.

But you can do what you want.