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tony-m avatar image
tony-m asked

Mounting Multiplus II 230V horizontally

There are many posts on mounting a Multiplus horizontally, but I've not been able to find an answer to my question either because Victron's recommendations have changed or there's some inconsistency among the different Multiplus models.

My model has a sticker reading: "MultiPlus-|| 12/3000/120-32 230V" with a part number: PMP122305010 and I believe the correct manual is online here because it matches the paper manual received with the unit (although I'm confused that the link above includes the word "quatro")

I want to mount it horizontally (with it's back still on a vertical surface) to fit my limited space. The animated .gif shows a metal cage I made to hold it and other victron components to allow maximum heat dissipation. I show it on the floor for stability, but I could raise it the recommended 10cm without problem.

m.gif

My main problem is that a search for "horizontal" in the manual turns up nothing. So, I'm stuck because I don't want to be forced to move it later because the fans are working too hard. It's going into a van and so extra noise like that would really be noticed.

User fcbrants had the same question and the link for the manual he provides says Quatro II on the front page. As I wrote I've seen many other posts struggling with this issue although often with some aspect different from my question.


Confused.

installation
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6 Answers
Jason - UK avatar image
Jason - UK answered ·

@Tony M As another rule of thumb, any losses from the AC to DC, or DC or AC transfer are lost though heat dissipation. As an example, my 5kVa unit pulling 5kw from the batteries, only provides 4.4kW as an average to the AC side, therefore 600w is emitted from the unit as heat energy.

Your 3kva unit, based on a 90% efficiency and a constant load will lose 400w of heat energy to a small space as per your description above, that space will over heat within seconds. You'll be needing fans to remove the heat from the Multiplus, and then more fans to remove the heat from the compartment.

My 2No 120mm USB fans I have under my unit seem to just about maintain the performance of my Multiplus for about an hour before the radiant heat emitted from my unit head heated up all the surrounding equipment which then starts radiating the heat back at the Multiplus.

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tony-m avatar image tony-m commented ·

Those are really interesting details @Jason - UK -- thanks.


If heat dissipation is that much of an issue, I'm thinking maybe I'll separate the unit from the rest and put it in a vertical position out in the open - next to the back of the driver chair -- a place that is not enclosed. Not really my desire to stare at the unit in the open like that but it's a least a little out of the way.

Update:

After considering more, I've decided to mount vertically, well-separated from other items AND put in a temperature triggered fan system.

I put post as the "accepted answer" because it made clear to me that heat dissipation is THE problem that limits the usefulness of these units...not just with theory, but with actual experience and numbers. Thanks again @Jason - UK

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iand avatar image
iand answered ·

What the manual says (10cm clearance all round) is to allow for plenty of convective airflow around the MP as well as cool air intake at the bottom and hot air exhaust at the top with low flow resistance.

If you put it into a closed box with added external fans (suck or blow) to blow air through the box (in at the bottom of the MP, out at the top) then the faster forced airflow means there should be no problem reducing this clearance, but I'd keep at least 5cm all round.


In this case it will make no difference whether the MP is mounted vertically or horizontally, the airflow will be the same. But make sure the fans you use are not ultra-quiet low-speed ones because these don't move much air, 2000rpm or above is recommended (but faster is noisier).


I have a setup like this on my boat with a Quattro 48/10000 in a cabinet using two Noctua 140mm 2000rpm fans (one blowing cold air in, one sucking hot air out) with no problem -- two fans are used like this because there's ducting to the outside which slows the airflow down. The fans are triggered by the fan assistant on the Quattro.


https://noctua.at/en/nf-a14-industrialppc-2000-ip67-pwm

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Jason - UK avatar image
Jason - UK answered ·

@Tony M Not that I can offer a formal answer to your question, 2 comments I do have.

The Multiplus has, albeit a IP rating which is not the best but I think I am correct in saying that is based on the horizontal position. If you were to install it horizontally, the ingress of dust may increase greater than it was designed for. My vertically mounted Multiplus II 5kva GX is installed in the cupboard under my stairs in my house, regardless, it needs taking apart and cleaning because of all the dust that has accumulated inside of it. You can see inside my unit where all the debris and dust is drawn into the unit. What affect would mounting the Multiplus horizontally have on the IP rating of the unit?

My 2nd comment, my unit struggles as it is in the vertical position with heat dissipation. Because of this, I have 2No 120mm USB fans mounted under or above the unit to help force the heat out of the top of the unit and therefore forcing the stack effect of the heat trapped within the unit. My concern with your proposed installation is hot to remove the heat from within the unit with no ability to have passive heat exhaust from what would be the top of the unit. I would have one of the AUX ports switching fans on to force air movement though the Multiplus when the internal fan engages, otherwise the unit will throttle down significantly, and keep the internal fan running for longer, which as per your comment above, maintain fan noise within the confined space. With my fans, I can maintain 4.2 - 4.4kW for over an hour. Without the fans, I'm down to 3.6kW within a hour.

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theo74 avatar image
theo74 answered ·

The Multiplus is designed to be hung up vertical, on the supplied black bracket. But it's not a to big deal when installing the Mulitplus horizontally, as longs as there is a free airflow, things will work fine.

(On the YouTube channel of Explorist Life you can see that it's done this way too: See this link.)


Inside a Multiplus is not much more than a big toroidal transformer, and a pcb with big heat sink, cooled by a pwm regulated fan. Those components do not have any restrictions towards a position.

I personally would add an extra external fan in the small compartment, to extra extract warm air. Combined with a simple grille on the other side of the compartment, to feed fresh air in.

Fans work a little bit as a vaccuum cleaner, so they collect dust. There fore it's wise to open the compartment every now and then, so clean/blow out all exccess dust with compressed air, etc.


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tony-m avatar image
tony-m answered ·

@Jason - UK I really appreciate the real world experience, though somewhat different from my situation. It's interesting that both you and @Theo74 discuss dust and fans. I am aware of the horizontal orientation shown by Explorist.life and also his advice about adding thermal regulated fans controlled by a cerboGX. I'm starting to think that adding fans is a good idea regardless of what orientation the Multiplus is in. I suppose I could also use the ventilation mode of the heater which you see in my animated GIF with a suitable duct arrangement.

So after all I've read, I'm starting to think I should accept the need for fans/ventilation (even if I did mount it vertically) and to turn my attention to the best fans/ventilation system.

In my plan there would be a couch covering both the heater and the electrical cage shown in my .gif, but the grill area of the Multiplus would not be enclosed since it faces the back of the drivers seat, and therefore is not easily viewed. That would, of course, provide more ventilation. And also all that metal of the cage would help to dissipate heat.

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Matthias Lange - DE avatar image
Matthias Lange - DE answered ·

I don't see a problem with horizontal mounting as long as you can provide a sufficient cooling/ventilation.

The manuals says:

The product must be installed in a dry and well-ventilated area, as close as possible to the batteries. There should be a clear space of at least 10 cm around the appliance for cooling.

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