Inverter noisy - what other options would you suggest?

[Ian B]

We've had a system installed with 12x Ulica UL-250M-60 Panels Ningbo Ulica Solar Science Technology Co., Ltd. a Mastervolt Sunmaster XS3200 inverter SunMaster XS3200 | Mastervolt Solar energy solutions installed in the meter cupboard under a staircase.

The temperature in the cupboard is a fairly constant 16.5 degrees, but the Inverter fan runs continuously, increasing in speed when high sun, and is unacceptably loud (it can be heard in the furthest bedroom upstairs.

The installer is considering replacing it and I'm wondering what you guys might suggest that is quiet, and fairly compact. Height and width aren't an issue but the depth from the wall is quite small with the Sunmaster which is an advantage).

I's also like to be able to monitor it on a PC, although not essential, so one with good comms would be ideal.

Any suggestions please?
Many thanks.

 

[JulianC]

The Mastervolt XS's are notoriously noisy so anything will be an improvement. The SMA Sunnyboy HF series spring to mind - built in bluetooth so you can monitor your system from your laptop using SMA's free software.

 

[pwboston]

Inverters will emit sound, the DB level is usually in the technical specifications of the inverter.

 

[FB.]

Don't some of the "outdoor" versions of inverters use metal cooling fins rather than a cooling fan?

I have a Power One Aurora 3600 (indoor version, not OUTD version) and it lives in a downstairs utility room. We put it there so that any distraction from it would be well away from any living or sleeping areas (including not in the loft above a sleeping area, where it might be audible).
At this moment, with the inverter running at about 80-90% of capacity (room temp remains fairly stable about 15'C), the cooling fan is running fast. If I close the door of the room, I can still hear it quietly in the hallway. If I go to another room (e.g. the kitchen) and close that door behind me too, I can't hear it any more.
In other words: it needs two doors between it and me for me not to hear it at all, but one door is enough to make it a quiet "background noise".

 

[SolarCity]

Installing it in a cupboard probably wasn't a great idea to be honest so you will probably find that the fan's life will shorten somewhat (unless it is a very big cupboard of course.)

Would moving the inverter not be a better option?

 

[moggy1968]

I would also go for the SMA, either 3000TL or HF. quiet, well made and with the best bluetooth IMHO

 

[Ian B]

Thanks for the replies.
Unfortunately Mastervolt don't quote noise figures, and when we contacted their Tech dept they said they don't have any! (maybe if they're all noisy that's why).
The SMA 3000TL spec says it has convection cooling and a noise rating of 25bD(A), whereas the 300HF says it has Opticool (so presumably vari-speed fan) and 38dB(A) - both of which would be quieter than the existing Sunmaster.

The cupboard has louvre doors so ventilation/heat buil-up isn't a problem, but they naturally don't block much sound.
I fully expect some, but the Sunmaster fan is VERY noisy, and a similar level to a sever room!
The only other location is the loft, and the noise it makes would still be audible in the room below - plus I'm not keen having electronic kit in the loft given the summer heat and winter humidity.

The fact the SMA's seem to have good monitoring options, including the possibility of their "Sunny Home Manager", is a big plus.

 

[nowty]

I started out with a Power One 3.6 indoor unit which was also quite loud when appraching full power output but had it changed for a Power One 3.6 outdoor unit which is mainly cooled passively by convection via a big external heatsink (it does also have an internal fan but you never hear it).

Fantastic difference, job done.

Your system will probably be more suited to the 3.0 version.

 

[Vegelen]

I would also go for the SMA, either 3000TL or HF. quiet, well made and with the best bluetooth IMHO

I completely agree.
The SMA 3000TL doesn't have a fan and is exceptionally quite- unless you are manifestly pneurotic.
The 3000 TL cools itself via a heat exchanger.
Larger SMA TL transformers have internal fans.
I would'nt install the inverter in a cupboard though, as it wont get sufficient ventillation.

 

[faulkn_c]

I had a Mastervolt XS5000 (16A max limited) fitted as part of my 4KW PV system before the last (but one) FIT deadline.
I didn't have a choice at the time, as my installer was scratching about to get the kit for the install.
It has galvanic (transformer) isolation, accepts 2 independent strings as it contains 2 inverters.
So far it's works well, runs cool and if you connect an RS232 to RS485 converter you can use the free Masterlog (crap) software to keep an eye on how it's doing.

But it is noisy.

Forrtunately mine is fitted in the Barn and the only things it annoys are the 2 old nags (horses) and a few chickens.
I've used SMA Windyboys in the past, no fan, but the large transformer hums quite a bit under load.

Perhaps you could fit sound absorbing panels behind the louvre doors? - spaced off to still allow air circulation.....

 

[KSOL72]

What about micro inverters? We fitted some Enecsys on a recent install and one of them in particular is giving off a real buzzing sound. Anyone had the same...?

 

[SolarCity]

Nightmare. Have you asked Enecsys what their take on it is?

 

[screwdriver]

If the inverter has to go close to a living area then I always veer towards the SMA inverters even though I love Power ones they have a really bad level of high frequency which some customers hear, (although some customers are too old to hear so don't mind it even though I can't stand next to the things when they are going full whack)

 

[KSOL72]

Enecsys say they give off a 'hum' but you can hear this crackling/buzzing standing in the driveway although it's only a chalet. They say it could be a loose connection or vibration against the rails...further investigation needed

 

[fitzsparks]

It might be worth checking out what the inverter is mounted to, as certain structures (wood & plasterboard generally) act as sound amplifiers. We have seen one mounted to a ply board in a loft, but the weight was taken on the ceiling joists and the noise was terrific. It is now mounted on a chimney breast still in the same loft and it can't be heard unless you really strain to hear it! This wasn't fitted or rectified by us, but I have been shown it by the client

 

[KSOL72]

Fitzsparks...these are micro inverters so mounted behind the panel on the rail itself

 

[SolarCity]

It might be worth checking out what the inverter is mounted to, as certain structures (wood & plasterboard generally) act as sound amplifiers. We have seen one mounted to a ply board in a loft, but the weight was taken on the ceiling joists and the noise was terrific. It is now mounted on a chimney breast still in the same loft and it can't be heard unless you really strain to hear it! This wasn't fitted or rectified by us, but I have been shown it by the client

Resonance is a big issue when mounting inverters. If you absolutely must mount on a timber frame (with firemounted board) then you really need consider some kind of dampening method.

 

[KSOL72]

SC, I'm on about Enecsys micros...thrown into inverter noise thread some posts back

 

[SolarCity]

KSOL, I know you were talking about microinverters. My response wasn't aimed at you.

You may wish to start a new thread.

 

[fitzsparks]

I wasn't talking about micro-inverters either. The original thread was a "normal" inverter mounted under the stairs making a noise. This is what I was hoping to offer my opinion about. Sorry for any confusion.