MultiPlus-II 48/5000/70-95 120V not accepting wide range 45Hz to 65Hz

Hi

I am unable to get my MultiPlus-II 48/5000/70-95 120V to accept a 120V AC at 50Hz input.

MultiPlus-II Firmware version: 2723557

VictronConnect APP v6.23:

System Frequency changed to 50Hz

Enabled accept wide input frequency range.

Settings were applied while the unit is on DC power only. Once 120V AC is applied the MultiPlus-II will not accept the input. (See below)

With reference to the manual:

the input range is adjustable for 50, 60 or 45Hz-65Hz. Once I apply all settings and connect the 120V AC @ 50Hz, then the MultiPlus-II does not accept the input. When I apply a source @ 60Hz the unit connects and starts to charge the battery.

After confirming the settings, I find that the frequency setting of 50Hz is not applied anymore and seems to revert to the default of 60Hz despite setting it to accept a wide range of 45Hz to 65Hz.

I am aware that for this unit, the output is fixed at 60Hz, when in inverter mode, but should it not follow the input frequency when connected?

This leads to my question: Why would it not accept an input at 50Hz?

What is the source of your 120v - 50Hz? If it is a small generator, then it could be possible to raise the frequency.

Have you tried the inverter in charger only mode with this source?

Hi

The last test source was from a Quattro 5000VA 120V set to 50Hz. I also tried our grid (220VAC 50Hz) with a step-down transformer. (220 to 110AC)

At 50Hz the inverter will not accept the input. When setting the Quattro to 60Hz, all works 100%.

Yes, I have tried charger mode only. I did notice that when using Ve.Config the option to set the frequency does not exist like it does with the 230VAC MultiPlus-II units. See below sample of a MultiPlus-II 230VAC

and the MultiPlus-II 120VAC

No System Frequency option.

“system frequency” is only for the output in inverter mode.

We had a similar question a few weeks ago with a 277V Quattro.

Thank you for confirming that, so as per manual the output is fixed and not adjustable, BUT it should accept a wide input range?

In our application we are happy with a 60Hz during inverter mode, however we do need the system to synchronize to 50Hz when an input is applied at 50Hz.

Is this perhaps a limitation of only the 120V AC models?

Here in Europe/Germany we don’t have much to do with the 120V models, so I can say much about that.

Hello @WernerS

I am experiencing the exact same issue with trying to charge batteries and passthrough a 120V 50hz AC input when connected to that type of source AC. Did you ever find a solution to allow this on the Multiplus 48v/5000 II 120V? Can someone from Victron confirm this unit will pass through 120v 50hz and use it to charge batteries as this is what my Victron dealer said it would do. It is important for us as our sailboat moves from US 60hz inputs to European 50hz inputs and we use a Victron isolation transformer to change the 240 to 120V when on Euro power. Please help as my dealer just isn’t any help with this level of technical detail!

Hi Mike,

I’m not sure when Victron implemented this design change, but I can confirm that certain MultiPlus-II models appear to use transformers that are optimized for a single operating frequency rather than a wide frequency range. This is likely part of a cost-optimization exercise, allowing for a smaller and more cost-effective transformer design.

As a result, unlike the Quattro models, which are designed to operate on both 50 Hz and 60 Hz systems, the MultiPlus-II is optimized for either 50 Hz or 60 Hz, depending on the specific model. In my case, the 120 V model appears to be optimized for 60 Hz only and does not support both frequencies interchangeably.

Which MultiPlus do you have exactly (product number)?
In the pricelist there are multiple models and one of them is labeled with “50/60Hz”
image
I guess only that model is able to work with 50Hz and 60Hz.

Based on your product description, it seems to be the case that only certain MultiPlus-II part numbers still support both frequencies. The manuals at the time for me was a bit misleading and my resolve was to return all the units and replace them with Quattro’s.

Thank you both for the clarification! I checked and my two units are PMP482505110 which apparently are 60hz only. I believe my installer ordered the wrong units. @M_Lange can you answer a couple questions so I am sure I am on the right path for a resolution?

  1. If I replace both units with PMP482505300 units I will still be able to have them setup paired for 240/120V split phase 60 hz USA type power output when inverting correct?

  2. If I feed ONE of the units with 120v 60 hz input and the “switch as a group” checkbox is unchecked (my current configuration) one unit will pass through the 120V 60hz AC power to the outputs while also entering “charger” mode and charging the batteries, meanwhile the other unit will stay in inverter mode and sync frequency so the output of both units will still be 240/120v 60 hz split phase USA type power. (this is the behavior of my current two units and this behavior is important to me)

  3. If configured the same way and I feed ONE of the new units with 120V 50hz power then it will pass through that 120v 50hz to it’s AC output and also enter “charger” mode to charge batteries. The other unit will stay in inverter mode and output 120V 60hz power to it’s AC output. The power between both units can no longer be 240/120v split phase as they are operating on different frequencies (50hz and 60hz respectively) so it is important NOT to hookup or run any 240V appliances (single dive compressor in my case) when on shore power utilizing the 50hz input described in this question. Do I have the expected beahvior correct?

  4. If I only replace one of the units with the new 50/60hz model can I still get the above expected behavior (including 240/120 split phase 60hz when no shore power is on) in all these above cases (assuming of course the 50hz input is being applied only to the new 50/60hz unit!)

I want to confirm there aren’t any programming changes needed to utilize the 50hz input power so please let me know if I have this wrong and if so explain how I could utilize both and what I should expect the behavior to be. Thank you so very very much!!!

Thanks @WernerS for your information! It is extremely helpful! (In my case the quattros won’t fit which is why we went with the MPIIs. Hopefully there is a solution here! (and totally agree the manual is super unclear on this point!)