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Tony Correlli avatar image
Tony Correlli asked

Air Conditioner shutting down system

Hello,

I have a 16,000 BTU AC 120v/ 13.5amp in my medium size boat. I have installed it to the AC2 output on the MultiPlus 12/3000/120. With shore power connected 120/30 amps The AirCon fan comes on, as the condenser clicks to start all power is lost Multiplus literally shuts down. Sometimes it resets other times it does not. If I switch Multi off for 5 seconds and back on Multi goes into bulk charging mode and appears to run fine, until Air Con tries to start again. Very bad when boat is unattended. I've hove gotten low battery lights, overload lights, and both low battery and overload lights lit at the same time.

Thanks,

Tony

MultiPlus Quattro Inverter Charger
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1 Answer
tilo avatar image
tilo answered ·

Can you give some information about your configuration? How much is AC Input Current limit?

Is the inverter disconnecting from the shore power when the Air Con tries to start?

Is "Dynamic current limiter" activated in VE.Configure 3? You might try with and without to see if something changes.

The low battery light is something you should investigate and try to eliminate first. Maybe the current draw at startup of your Air Con is causing the voltage to drop and shuts down the inverter. What is the configured shutdown voltage of your inverter? Are your batteries in good condition and of sufficient size? Check all cable connections. What is your battery cable size and length? You might try to measure the battery voltage at the inverter terminals at the moment when the Air Con starts, ideally with a volt meter that has a min/max reading. If voltage falls below your disconnect voltage, repeat the measurement at the battery terminals. If you have a lot of difference, then you should improve cabling between the battery and the inverter. This voltage drop might also be remedied by using a voltage sense cable from the inverter to the battery terminals. But as you also mentioned overload lights, the voltage sense cable might not prevent the overload situation, as overload is based on current limits, and with low battery voltage the required current increases to meet a certain output power. That means a low battery voltage affects somehow the maximum output capacity of the inverter.

If the voltage drop at the battery terminals is also high, you might try lowering the shutdown voltage of the inverter. If that makes disappear the low voltage light, but still leads to overload, try adding temporarily (for a test) more batteries, maybe a car starter battery.


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Tony Correlli avatar image Tony Correlli commented ·

Thank you Tilo, this afternoon I will start with the tests.

TonyC

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Tony Correlli avatar image Tony Correlli commented ·

I used VE Configure. The Dynamic Current Limiter was "unchecked" I "checked" the box. Also I "Unchecked" the overruled by remote box and set the AC Input current over load to 30.0A

Air Con has now be running for 24 hours with no system shut down. I guess I should have made one change at a time to truly know what the hangup was. I will go back onto the system and test one item at a time and report back. Thanks again Tilo.

TonyC

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craig-pretzinger avatar image craig-pretzinger Tony Correlli commented ·
Did you ever figure out what the hangup was?


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Alexandra avatar image Alexandra ♦ craig-pretzinger commented ·
@Craig Pretzinger

The unit would have been trying to power assist with the Ac current limit set lower and the dynamic current limit on. It was not able to do so, possibly because of the batteries not being able to support the high amp draw, so their voltage was collapsing.

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craig-pretzinger avatar image craig-pretzinger Alexandra ♦ commented ·
I finally got mine to work for my AC. Turning on dynamic current limit is what did the trick. I did lower mine from 50a to 30a, since my incoming shore box is a 30a … is this correct, or can I raise it to 50a? Is the 50a for current out of multi or current too multi
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