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misterpitbul avatar image
misterpitbul asked

Problem : Short Circuit on a MultiPlus-II GX 48/3000/35-32 with only Main-AC connected

Dear All,

I am new in the Victron community.

I achived a Victron MultiPlus-II GX 48/3000/35-32 with the goal to build an UPS for my servers.

A 1st. test with only Main-AC connected to AC-IN was successfull; however the device went into inverter mode with only AC-OUT1 delivering power; AC-OUT2 no power (checked with a AC-tester).

Starting the device a 2nd time resulted in a short-circuit on Main-AC; another try => same result...

Did somebody experience the same problem... ?

(To confirm : Main-AC-IN has been connected correctly; Phase-to-Phase, Null-to-Null)

Pierre

Multiplus-II
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Mike Dorsett avatar image Mike Dorsett commented ·
Generally not a good idea to run these without a BATTERY connected FIRST as per the manual....
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nickdb avatar image nickdb ♦♦ Mike Dorsett commented ·
And by generally you mean NEVER a good idea, In fact the complete opposite of a smart idea.

A great way to break something.

Imagine the money victron would save not making manuals that people are determined not to read.

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misterpitbul avatar image misterpitbul nickdb ♦♦ commented ·

Hi,

Thanks very much for your sense of humour, but I read a lot of "official" Victron manuals; even before deciding to buy a MultiPlus-II GX... In one of those manuals it is even mentioned that the device can be operated EITHER on Main, Battery or BOTH... (see below)... Otherwise how could I configure the type/model of batteries to be used ????

Killing my batteries by using incorrect configurations during the 1st start ????


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1664825985893.png (135.4 KiB)
misterpitbul avatar image misterpitbul misterpitbul commented ·

So, my idea was to start the MultiPlus on Main only, connect to the VE-bus, do the necessary configurations, shut down, connect the batteries and restart the complete equipment...

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Alexis Hanicotte avatar image Alexis Hanicotte misterpitbul commented ·
Same here. Short-circuit on second startup with only AC-in connected. That left me puzzled until I read your post. Well I'm still puzzled actually.

The manual does not say not to run without battery.

It feels odd to have to connect them without first checking the configurations. Besides, the battery type I use is NOT the one setup in the standard settings.

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thalium204 avatar image thalium204 Alexis Hanicotte commented ·

Same problem here - I have installed a brand new Multiplus II GX 5000VA.It is powered (EDF Grid) upstream by a 32A circuit breakerand connected to the AC IN input.For the moment there is no connection on the 2 AC OUT outputs and no battery connected.Problem, when powering up by the ON/OFF button at the bottom right on Position I, the Multiplus lights up then after a few seconds of the initialization phase there is a relay engagement noise inside(or contactor) then the 32A circuit breaker trips!!Same when the ON/OFF button is in position II.The earth/ground is well connected. Do you have any idea where the problem could come from?Wouldn't the Multiplus be out of order?

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ejrossouw avatar image ejrossouw commented ·
Just for clarity, can you confirm the size of circuit breaker that tripped? I will not discount an aging "faulty" circuitbreaker that were simply overloaded by the high inrush current or a too small one. This why it is best to always use batteries and how all those off-gridders without mains have always done it.
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2 Answers
Alexis Hanicotte avatar image
Alexis Hanicotte answered ·

I experienced the exact same problem.

To start the device without battery, I figured out I needed to use the second position of the switch: II / Charger Only

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thalium204 avatar image
thalium204 answered ·

Hello, Same problem with Multiplus II GX 5000 VA. I have installed a brand new Multiplus II GX 5000VA.It is powered (EDF Grid) upstream by a 32A circuit breakerand connected to the AC IN input.For the moment there is no connection on the 2 AC OUT outputs and no battery connected.Problem, when powering up by the ON/OFF button at the bottom right on Position I, the Multiplus lights up then after a few seconds of the initialization phase there is a relay engagement noise inside(or contactor) then the 32A circuit breaker trips!!Same when the ON/OFF button is in position II.The earth/ground is well connected. Do you have any idea where the problem could come from?Wouldn't the Multiplus be out of order?

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nickdb avatar image nickdb ♦♦ commented ·

These systems are not designed to work without a battery. Attach a properly sized pack before you make an expensive mistake.

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thalium204 avatar image thalium204 nickdb ♦♦ commented ·
Thanks for your message - I dont understand , I have first to set-up properly the type of Battery , I have PYLONTECH , then one's the setting is done I connect the battery. Why should I connect the battery if those one are not the correct one ? In the manual there is nothing written about the mandatory of battery connection before power-on the Multiplus. Do you think it is damaged ?
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Matthias Lange - DE avatar image Matthias Lange - DE ♦ thalium204 commented ·

In inverter mode you can't damage the battery.

Connect the battery, configure the MultiPlus and than connect AC IN and OUT.

If the battery is connected to the GX device via BMS-Can, the battery is automatically controlling the MultiPlus via DVCC.

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daniel-feist avatar image daniel-feist commented ·
5000VA Mulilplus II should use 50A circuit breaker upstream. Did you get this working on the end?
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