Consequences of overloading inverter

[chadmichael]

I'm building a 400 watt system for a van, pretty much following Will's recipe for that system. Ill have a 2200 watt inverter and I plan to attempt to use a induction cooktop with it. That cooktop is rated at 1800 watts and I know that it would require a much larger inverter due to the fact that its maximum draw is going to be higher than the 2200 Watts. My hope is that I can still make use of an induction cooktop at half power. If it can still boil water at this power level, it still would be a very convenient, efficient way to boil water, etc.

If I take a trial and error approach, ie I will use the induction cooktop and see what power level my system can adequately support without blowing a fuse, do I face any dangers? or costs?

My system will have a fuse bolted on to the positive terminal of the battery and the inverter will directly attach to that. I have calculated that this fuse will be 230 to 250 amps.

If I pull too hard on the inverter, by turning the induction cooktop up too high, what are my consequences? Is it as simply as blowing the main fuse? Is it then just the hassle of replacing that fuse? If that were the case, could I put a breaker there too take the "cost" out of my period of learning proper level for using the cooktop?

 

[Bud Martin]

If the inverter has poor protection against overload, it may just blow up before the fuses are blown.
What is the make and model of the inverter?
For you to get 2200W on the AC output side of the inverter, the input power will be higher due to system and conversion loss, 15% is typical, so 2200W/0.85 = 2588W on the input side of the inverter, if your system is 12V then the current draw from the batteries will be 2588W/12V = 215A, the fuse should be 215A x 1.25 = 268A, so you just have to find something close to that.

 

[chadmichael]

I have the Giandel 2200 Watt inverter with a 200 Ah LiFePO battery. This comes from Will's recipe here. He says 2 x 100Ah batteries; I have one. Additionally, Giandel says 200 Ah or higher is recommended. So, now you have me wondering whether I need a 3rd battery to get to 300 Ah.

But to stay on point for my original question, what happens if the appliance draws a higher load than the inverter can provide? For instance, the induction cooktop is turned on at full power 1800Watts, and, from the Giandel literature, this can create a 3 to 5x start up load. Assuming the best, this could load my inverter with an ask of more than 5000 Watts. What will happen?

The overload protection will be triggered first? Then if that fails, the fuse on the hot wire from the battery to the inverter will fail? My concern is that replacing the fuse would be a costly way to discover by trial and error the maximum power setting I could use my induction cooktop at. But maybe all that will happen is the inverter turns off via its overload protection?

FYI, Here's the language from the manual with respeect to overload protection and short circuit protection.

Overload protection: The inverter will automatically shut down when the load is higher
than the rated power. The buzzer will whistle continuously. Turn off the inverter and
resume to normal operation after taking away the excessive load.


Short-circuit protection: The AC output will be automatically shut down when short
circuited. It will automatically reset after the problem is solved.

 

[time2roll]

Once should not be an issue. Could get a Kill-A-Watt meter and actually get a reading on the load and power factor.
Or if you turn it up slowly the inverter should tell when max power is approaching. Best to aim for 80% max for regular use.

 

[Bud Martin]

If you get good brand inverter the protection circuit may react fast enough to shutdown before damage will happen. I do not know how good the Giandel handle overload. You cannot really tell until you have the unit to try out with the load you will be using.
Tire 1 inverter such as Victron will more likely to perform better and have better protection circuit.
There are some videos showing what happen to the inverter if short circuit is apply to the outlet, some unit survive some don't.
Manufacturer can make any claim they want, but you will find out in the real how well it really works when you try it.
And of course the battery has to be able to supply enough power for the load, and the BMS can handle it or not.

 

[DerpsyDoodler]

If you get good brand inverter the protection circuit may react fast enough to shutdown before damage will happen. I do not know how good the Giandel handle overload. You cannot really tell until you have the unit to try out with the load you will be using.
Tire 1 inverter such as Victron will more likely to perform better and have better protection circuit.
There are some videos showing what happen to the inverter if short circuit is apply to the outlet, some unit survive some don't.
Manufacturer can make any claim they want, but you will find out in the real how well it really works when you try it.
And of course the battery has to be able to supply enough power for the load, and the BMS can handle it or not.

What's the surge rating for the inverter? is it 2200w continuous or is that its peak surge rating? Usually you can get 2x surge from a decent high frequency inverter. Thats for fractions of a second, lower for longer, etc. Refer to your inverter manual. Also the manual for your induction cooktop may give an idea of its peak surge needs.

 

[Bud Martin]

Most HF Inverter can only handle surge duration of around 30 ~ 60mSec which is only about 2 ~ 4 cycles of 60Hz.
OP should look at the spec of the inverter, also spec of the load as suggested.
And then again, can the inverter go into shutdown fast enough if surge is longer than the spec?

 

[Rocketman]

I don’t know on your inverter - but it I will share what happens to my Victron.

We have a Victron Multiplus 12/3000 - with lithiums. If my wife is using the microwave and then she tries to use the toaster (that overloads the inverter), we get a low voltage warning beeping on the CCGX (system monitor) as the inverter shuts down for about 10 seconds. Then it reboots and she will restart just one at a time.

I don’t know what will happen to your inverter - good luck. You may want to overload it once to try it - because if it fries something- then you know and can fix it - better on a trial than when you are depending on it.

 

[Browneye]

Weird. I use LPG. [shrug]

 

[Roswell Bob]

Why would an induction cook top have any start-up surge?

 

[gelmjw]

Why would an induction cook top have any start-up surge?

I guess because it has the word induction in the name. It is not a resistive load.

 

[Bud Martin]

The surge is mostly be from the DC power supply filter caps, the power supply converts incoming AC to DC to supply dc Voltage for the RF drive circuit. 1800W induction cooking may have pretty good size capacitor bank, I do expect them to have inrush current limiter when the power supply is first plugged into the AC outlet.

 

[DerpsyDoodler]

Running power through/to any inductive load always meets resistance on startup as inductive loads push back while the magnetic field builds across the coils. its known as inductive reactance.

 

[pollenface]

I overload mine from time to time trying to start big AC motors, it just cuts the output breifly which gives me time to disconnect the load.

I've had other ones where you have to pull them apart and replace the fuses.

 

[HRTKD]

I've overloaded my Xantrex ProWatt 1000 (MSW not PSW) inverter a couple times on purpose. It just shuts down and I have to manually restart it. This is an older Xantrex, perhaps from when they were built a little better. It was free, so I wouldn't have been out any money if I blew it up. I don't plan to abuse my new Multiplus.

Not all inverters are created equal.

 

[DerpsyDoodler]

I've overloaded my Xantrex ProWatt 1000 (MSW not PSW) inverter a couple times on purpose. It just shuts down and I have to manually restart it. This is an older Xantrex, perhaps from when they were built a little better. It was free, so I wouldn't have been out any money if I blew it up. I don't plan to abuse my new Multiplus.

Not all inverters are created equal.

I suspect the victron should handle as well or better, but i don't blame you for not wanting to find out.

 

[gelmjw]

Running power through/to any inductive load always meets resistance on startup as inductive loads push back while the magnetic field builds across the coils. its known as inductive reactance.

Would that surge happen only once at startup, or every time the unit cycles on/off while in use?

If so, the inverter-induction units with the steady power draw have a big advantage when running from a small inverter generator. Right?

 

[DerpsyDoodler]

It would happen whenever the magnetic field across the coil changes. That said, the slower the magnetic field changes, the less reactance you'll see. Imagine a switch that just opens and lets whatever current the device wants to suck flow vs having a knob that allows current to slowly ramp up. Check out the youtube channel RSD academy. Bob Duhamel (the channel creator) explains inductive loads pretty well. He's also made several videos covering inductive and capacitive circuits,

 

[A.Justice]

I have that Giandel 2200 watt inverter. Mine trips when it gets to 2300 watts or so. It's never popped a fuse, and the overload protection seems to work very well, it cuts off for like 20 or so seconds then comes back on.

 

[Bud Martin]

OP: What is the make and model of the induction cook top?

 

[12VoltInstalls]

because it has the word induction in the name. It is not a resistive load.

If I’m not mistaken it heats by induction; not electrically inductive. Maybe I’m wrong. I have low interest in electricity fed heating products beyond a coffeemaker or toaster.

My Giandel 1200W pure sine inverter shuts down reliably when overloaded but I’ve only done that a few times.

 

[gelmjw]

If I’m not mistaken it heats by induction; not electrically inductive. Maybe I’m wrong. I have low interest in electricity fed heating products beyond a coffeemaker or toaster.

My Giandel 1200W pure sine inverter shuts down reliably when overloaded but I’ve only done that a few times.

You QUOTED me as posting "because it has the word induction in the name. It is not a resistive load."

What I posted was "I guess because it has the word induction in the name. It is not a resistive load.". Italics identify the missing passage.

I do not appreciate being misquoted. You apparently went to some effort to modify my original post when composing your reply. Was there some intent to misquote, or was that a simple accident?

 

[12VoltInstalls]

do not appreciate being misquoted. You apparently went to some effort to modify my original post when composing your reply. Was there some intent to misquote, or was that a simple accident?

I have no idea what you are talking about.
I highlighted a snippet and hit ‘reply’ and provided two things to be helpful. I’m sorry you are offended but chill. I snipped and replied just like everyone’s been doing since the 1990s
I’m sorry you are offended but that is exactly what you said and I have no clue what you are offended over. Sorry

If I’m not mistaken it heats by induction; not electrically inductive. Maybe I’m wrong

If I’m wrong just say so

 

[gelmjw]

it heats by induction; not electrically inductive

If you are good with this, then I will understand.

 

[12VoltInstalls]

If you are good with this, then I will understand.

I don’t know what your deal is.
You aren’t making any sense, but I guess you want to argue about something… so sorry- I neither know what about nor do I want to argue.
But feel free to go on ahead without me…