Victron Multiplus Mounting Orientation

[OrangeCrush]

I have seen some pics by some that show the Victron Multiplus mounted upside down. I would like to do the same but can not find anything in the manual to say that is OK. Anyone have more info on this and/or feedback on how well it works mounted upside down? Also, did you do anything special to the surface before setting it on its head?

[vanderwielen]

I've installed MPs. I've never seen any installs upside down. I suspect it would work if you keep the areas around the unit clear per the recommendations of Victron. The only concern I would have would be that the top mounting bracket would provide no support. I'd suggest sideways before upside down. Good luck.

[richard5933]

What would be the advantage of upside down?

[goldenchase]

Originally Posted by OrangeCrush

I have seen some pics by some that show the Victron Multiplus mounted upside down. I would like to do the same but can not find anything in the manual to say that is OK. Anyone have more info on this and/or feedback on how well it works mounted upside down? Also, did you do anything special to the surface before setting it on its head?

A few observations having been near the MultiPlus II working on the trailer for the last few months.

Multiplus II was designed to be mounted vertically to enhance passive cooling. My guess is they mounted the more heat sensitive components at the bottom. The more the unit can cool passively the less demand will be placed on the fan to cool. So the fan does not come on if passive cooling is doing the job.

My Multiplus II is mounted in the center closet vertically currently without ventilation. In normal operation without charging the closet temperature is about 2 degrees higher than ambient outside the closet. I am pretty sure for Summer operation during extended charging (takes about 4 hours for my 400ah lithiums to charge if fully discharged) I will need to either leave the closet door open or put in some supplemental cooling.

So the bottom line is that sub optimum mounting and/or enclosed locations will result in more fan noise or at worse thermal shut down.

[uncle_bob]

Hi

The Multi's are heavy beasts. The transformer in the unit is pretty massive. Getting them securely mounted would be a concern in odd configurations.

Cooling wise, as long as you have airflow, it will operate fine. Just make sure it has cold air in one end and the hot air out the other end has someplace to go. Will the fan run 2% more often in this or that configuration? Maybe it will, no harm done as a result ... Ours has been mounted flat for 5 years with absolutely zero issues.

Bob

[OrangeCrush]

Thanks for that info Bob. Flat will be my second choice and after playing Tetris for a while today I may make it my plan. Their service manual actually mentions it as acceptable but not optimal. It says nothing about standing it on its head.

richard5933 - I am trying to mount it under the bed in a 25FB. They're drawing shows 100mm clearance to combustable material top and sides. The clearance under the bed is just 1" if it is mounted right side up on the ground and access to electrical connections are very difficult. Upside down you can use the metal plate floor as a heat sink and have easy access to wiring on top. Problem I see is that the convection direction is reversed and will change again when the fan kicks on.

[goldenchase]

Originally Posted by OrangeCrush

Thanks for that info Bob. Flat will be my second choice and after playing Tetris for a while today I may make it my plan. Their service manual actually mentions it as acceptable but not optimal. It says nothing about standing it on its head.

richard5933 - I am trying to mount it under the bed in a 25FB. They're drawing shows 100mm clearance to combustable material top and sides. The clearance under the bed is just 1" if it is mounted right side up on the ground and access to electrical connections are very difficult. Upside down you can use the metal plate floor as a heat sink and have easy access to wiring on top. Problem I see is that the convection direction is reversed and will change again when the fan kicks on.

Things to consider. The battery cables are very heavy so you want the batteries for many reasons including weight to be near the MultiPlus. That gets into the whole issue of lateral balance of the trailer. If the 50 lb Multiplus is grouped with the batteries the potential for lateral imbalance problems arise. I solved that to some degree by installing a "heavy" Bosch hot water heater on the other side. The Bosch 110v hot water heater has an 8 gallon tank so in essence I am using 70lbs of water ballast in that tank to correct for the lateral imbalance of having the batteries and Multiplus on one side of the trailer.

So many moving parts to these placement decisions.

[OrangeCrush]

Originally Posted by goldenchase

Things to consider. The battery cables are very heavy so you want the batteries for many reasons including weight to be near the MultiPlus. That gets into the whole issue of lateral balance of the trailer. If the 50 lb Multiplus is grouped with the batteries the potential for lateral imbalance problems arise. I solved that to some degree by installing a "heavy" Bosch hot water heater on the other side. The Bosch 110v hot water heater has an 8 gallon tank so in essence I am using 70lbs of water ballast in that tank to correct for the lateral imbalance of having the batteries and Multiplus on one side of the trailer.

So many moving parts to these placement decisions.

hmmm - thanks for bring that up. I never considered lateral imbalance. I will fold that into my Tetris work today.

[goldenchase]

Originally Posted by OrangeCrush

hmmm - thanks for bring that up. I never considered lateral imbalance. I will fold that into my Tetris work today.

Let me know if I can help. I scratched my head for a month trying to figure out where to put all the pieces. My biggest surprise was how much 4/0 cable weighed at 1.6 lbs per foot. For my install that was an addition 30 lbs of weight or the equivalent of another lithium battery.

[OrangeCrush]

Originally Posted by goldenchase

Let me know if I can help. I scratched my head for a month trying to figure out where to put all the pieces. My biggest surprise was how much 4/0 cable weighed at 1.6 lbs per foot. For my install that was an addition 30 lbs of weight or the equivalent of another lithium battery.

Thanks. I may take you up on that however mine is a bit different as I have the 25FB queen. So far it looks like I should be able to keep most heavy gear close to the middle (side-side) of the trailer under the bed. I've been pondering for 3 weeks now so looks like I may pass your month.

[uncle_bob]

Originally Posted by OrangeCrush

.....Upside down you can use the metal plate floor as a heat sink and have easy access to wiring on top. Problem I see is that the convection direction is reversed and will change again when the fan kicks on.

Hi

The Multi is very much an air cooled device. A metal plate going anywhere isn't going to do much of anything to cool it. You need cold air in one side and hot air exhausting out the other side. Put it in a small box so the air goes in circles ( hot loops around to cold) and it will not cool very well.

Bob

[goldenchase]

Originally Posted by OrangeCrush

Thanks. I may take you up on that however mine is a bit different as I have the 25FB queen. So far it looks like I should be able to keep most heavy gear close to the middle (side-side) of the trailer under the bed. I've been pondering for 3 weeks now so looks like I may pass your month.

No experience with the queen challenges. Here is a good video on active cooling of the Victron equipment if that becomes necessary.

https://www.youtube.com/watch?v=aesa5mJJfNU

[OrangeCrush]

Originally Posted by uncle_bob

Hi

The Multi is very much an air cooled device. A metal plate going anywhere isn't going to do much of anything to cool it. You need cold air in one side and hot air exhausting out the other side. Put it in a small box so the air goes in circles ( hot loops around to cold) and it will not cool very well.

Bob

Thanks Bob. I definitely misspoke. I meant to imply that the metal plate would not be a combustable.

[uncle_bob]

Originally Posted by OrangeCrush

Thanks Bob. I definitely misspoke. I meant to imply that the metal plate would not be a combustable.

Hi

I'm a bit unclear on just where Victron comes up with their "fireproof surface" recommendations on various items. I have not seen any significant amount of heat on the surface of any of their products. It may be an EU rule about gear that can take a lightning hit and heat that way .... no idea ....

Bob

[Wabbiteer]

Here is a peek inside my Multiplus - modular design has ‘smokestack’ vertical layout to boost passive convection cooling yet conductive/radiant heat pathways & avoiding dead airspace are engineered in too…

Looking at it closer, if trying for a horizontal vs. vertical placement then avoiding a level mounting position - place it at a fifteen degree angle or better - will extend components lifetimes by a goodly amount, and maybe a pivoting mount so it operates face down would help better overcome stagnant air and sun/weather boosted ambient temperatures…

Remember that appliance should* be around ten or fifteen years, it’d be easy to be the Joe Somewhen who thoroughly cooked it and then passed if off onto others with trouble built in to it…

[uncle_bob]

Hi

Having spent a lifetime designing this sort of stuff, I don't see any significant reason to avoid mounting it horizontally ..... It will likely outlast all of us mounted any way you decide to. That *assumes* you have reasonable air flow when the fans come on. If you don't, it will indeed not last as long.

Bob

[Glen Carter]

Originally Posted by uncle_bob

Hi



I'm a bit unclear on just where Victron comes up with their "fireproof surface" recommendations on various items. I have not seen any significant amount of heat on the surface of any of their products. It may be an EU rule about gear that can take a lightning hit and heat that way .... no idea ....



Bob

I think it's mostly a "liability" disclaimer.

[daleyocum]

My Multiplus 3000 is mounted vertically and upside down as you describe. It was much easier to run the heavy cables to it that way. It’s in the outside compartment of our FC25FBT. I do open the outside hatch if it’s doing something intense, like running the AC for expense periods, but most of the time it’s not much warmer in that compartment than the outside temperature.

The Multiplus is so efficient it doesn’t seem to get very hot except when under full load.

[OrangeCrush]

From that picture I am betting the brunt of the heat generated is from the two transformers on the side and a bunch of power FETs attached to that heat sink on the back of the unit. It looks to me like the fan location is designed to pass air over the heat sink fins. If the fan is running I don't think orientation matters but adequate ventilation for bottom and top sides does. I have a thought on a location for mounting the unit upside down which would provide good side/top ventilation and allow for a nice wiring layout to the batteries. I'll do some part placement and take a pic and mark it up for comment. I really appreciate everyones input on this.

[OrangeCrush]

Originally Posted by daleyocum

My Multiplus 3000 is mounted vertically and upside down as you describe. It was much easier to run the heavy cables to it that way. It’s in the outside compartment of our FC25FBT. I do open the outside hatch if it’s doing something intense, like running the AC for expense periods, but most of the time it’s not much warmer in that compartment than the outside temperature.

The Multiplus is so efficient it doesn’t seem to get very hot except when under full load.

Thanks, that helps a lot. Are your batteries under that plywood with all the electronics and what is the dimmer for?