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rien avatar image
rien asked

Multiplus 12/1600/70 overloading generator when running loads

hello

can somebody help me setting up my multiplus with victron connect.

the problem is that when I charge my batteries with a 1000watt generator

all is fine until either the central heating burner or the cooker burner on my boat switch on. they each have power consumption of 10 amp but the power spike is much much higher.this results into the generator being overloaded when on eco mode

i tried the soft ramp option but it is not effective enough I also limited the power input with the multi control panel . this now results into the multiplus switching off and than after a few seconds to come on again .

I want the multiplus to take the power load from the batteries and not from the generator when charging.

thanks


.


I

powerassist
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klim8skeptic avatar image klim8skeptic ♦ commented ·

all is fine until either the central heating burner or the cooker burner on my boat switch on. they each have power consumption of 10 amp

10 amps each at 230v ac?? Not remotely possible.


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rien avatar image rien klim8skeptic ♦ commented ·

I meant 10 amps at 12 volt comsumption from my battery bank

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rien avatar image rien commented ·

This is not going very well

I will start over again

On my boat i have a 400 amp 12volt battery bank

Everything electric is 12 volt except the 2 burners , they are 220 volt and consume 120 watt each and are controlled by thermostats

I charge the battery bank with the multi combi inverter with an ac invertergenerator 1000 watts

When i am charging the power into the batteries is around 40 amps and dropping depending on soc.

If during charging one of the burners switches on the the multi switches of and than back on again after a few seconds

Question why?

Question 2 what can i do to prevent this from happening

Thanks


I


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klim8skeptic avatar image klim8skeptic ♦ rien commented ·

Are you sure that your hot plates are only 120w??

Do you have a mk3 cable to program the multi?

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rien avatar image rien klim8skeptic ♦ commented ·

Yes i am certain

I do have a mk3 cable to program the multi with my laptop

I have no problem with the multi when i have shorepower

I have no problem when the generator is not connected

I have limmited the the amount of charge with the victron multi control pannel

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rien avatar image rien rien commented ·

Even when the batteries are nearly full and take no more than 8amps (12 volt) of charge this happens.

The multi trips and comes on a few moments later


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2 Answers
alex-rhys-hurn avatar image
alex-rhys-hurn answered ·

Hi,

So, I understand your AC Load is 1 x cooker at 10 Amps and 1 x central heating at 10 Amps.

I assume (because you haven't said) that this is continuous load.

So that is 20A @ 240 volts (volts assumed as you havent said) which is 4800watts of power.

The Multiplus 12/1600/70 can only do 1300watts continuous at 25 degrees celsius.

The Multiplus can do a short (few milisecs) overload of 3000watts.

So, you cannot run both of your appliances at the same time.

If you run 1 appliance at 10A @ 240v then its 2400 watts, so you cant do that either.

However to muddy the water, you may find that the appliance doesn't draw the 10A constantly but only during start-up. Did you measure this with a clamp meter?

If that's the case, then you may be able to get away with the start-up load of 2400w for one appliance for short time, then the appliance reduces its consumption hopefully below the 1300watts the inverter can do.

So, you need more data on your appliances.

Having said all that if you are trying the PowerAssist feature, so that 1000w is from generator and 1300w from inverter, that will still only be about 2300w which is still less than the 2400w of a single appliance.

Also, is your generator actually giving (or capable of giving) 1000w? or is it nameplate rated at 1000w? Or maybe 1000va? Most small gensets cannot give the full load that it says on the sticker, at least not for extended periods of time.

Finally, the ability of a generator to spin up in response to a heavy load (step loading) is determined by various factors, a significant one is the mass of the flywheel where a heavy one can push through the load as the engine governor fuels the engine and the engine can respond. The rule of thumb for generators in resistive load scenarios is to oversize generator by 30%, but here you are trying to use PowerAssist as your "flywheel" but you still need the inverter to be able to have enough capacity, which you don't.

HTH and correct me where I am wrong, as I am still learning.

Alex

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rien avatar image rien commented ·

Sorry for the misinformation i gave

The two burner draw 10 amps each at 12 volt

Not 230 volt so lets say they draw 120 watt each

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alex-rhys-hurn avatar image alex-rhys-hurn commented ·

Wow, would have saved me some time telling a long story if I had all the facts at the beginning!

OK, so is the below diagram correct?

  1. Generator to Inverter. (assuming the generator is an AC generator and not a DC one.
  2. Inverter to charge batteries.
  3. Loads are connected to batteries directly at 12 volts?

That means that its 240w DC. But DC is often easier spoken about in Amps.

So the inverter is only acting as a charger/ powersupply?

If the above is true, then are you asking why the Inverter is not putting out the 70Amps of DC from the Generator?

I dont know how to work out how many AC amps are needed for the inverter to supply the DC Amps needed.

You havent said what size type your batteries are. Please do.

But in theory the charger part of the multiplus should be able to provide the 20A needed for the loads, plus something left over to charge the batteries, assuming (hahaha) that the batteries are not so large that they plus the load overloads the charger.....

So, we now need photos, drawing and all the info from you in order to help out.

Alex

p.s. luckily I can type fast.

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rien avatar image rien alex-rhys-hurn commented ·

The generator can cope with 70 amps battery charging continues.

I did mention my battery bank 12 volt 400 amps.

I think the problem is the spike when the burner switches on.

What will happen when i switch on power assist on the multi

Will it than take all the load from the battery bank and not from the generator???


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Alistair Warburton avatar image
Alistair Warburton answered ·

Has anyone mentioned generator assist?

If the system copes when on batteries and shore power then assist with an appropriate AC limit, dynamic, and a fairly trimmed boost should work too.

I was running a 2kW inverter gen, in eco mode, into AC1 and not having any issues with 2 induction hobs at 2kW each simultaneously (MultiPlus 48/5000/70-100 / Champion DFi on LPG)

I am currently using a larger Champion DF, capable of circa 5kW on LPG and its having power quality issues when charging...
I just spent a few of hours winding chokes to try and remove the need for the weak AC setting and stabilise some very noisy control loops so perhaps I know less than I think I do.

I don't want to hijack this post but my experiments and the issues prompting them are in another post if anyone is interested (Bat temp OK, charge still Limmited...?)

Al

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