Schneider XW Pro 6848 - Loud Humming Noise

[patsfan1986]

Thank you in advance for your help.
Created a short video below of my situation. The inverter is in my basement so this humming noise radiates throughout the house (got a small house).
What's wild is the hum noise stops when I turned off AC1 IN.... My loads are using PV and Battery as energy... I only have AC1 IN on as a backup.... so its not really being used......... yet..........its the reason for the humming noise.

Any thoughts? I have a ticket in with Schneider but would love to get your opinions before consulting with them.

 

[RCinFLA]

It is hard to quantify the level from the video and you do have it mounted on a plywood backing board that may act as sounding board.

Is inverter active with AC output before AC1 is applied? With inverter active, with no AC input, should be the reference level of sound.

If inverter is active, and buzzing starts after it connects to AC1 input, that would likely be improper AC voltage/phase alignment between inverter and AC input source. If you have an offset alignment issue you may also see an increase in inverter DC idle current when it connects to grid (assuming no charging power is taken from AC input).

If AC input has significant sinewave distortion it can also increase buzzing sound.

If your battery starts charging with significant AC input current, that would be a normal expected increase in transformer buzz due to the additional load current flowing through inverter transformer. The buzz would decrease as charging current is reduced.

If your L1-N and L2-N AC input voltage is imbalanced in level it will also put an additional load on inverter transformer. The inverter center tapped transformer secondary will try to correct the AC input phase voltage imbalance. The inverter will release from AC input if imbalance of AC input neutral to L1, L2 gets too much. When connected to AC input, with no AC output loads, you can check the AC current on L1 and L2 AC input lines, neutral should not have more than a couple of AC amps, zero if perfectly balanced on L1-N-L2 voltage balance.

You might want to check inverter output L1-N and L2-N AC output voltage without AC input connection. Although unlikely, it is possible the transformer windings number of turns was screwed up and not the same on each 120v AC phase side. Usually, the two windings are done with parallel wires so having different number of turns is highly unlikely.

Other possibility is pass-through relay buzzing but that is less likely.

 

[Quattrohead]

I have no experience with these inverters but I do know that does not sound good.

 

[LydMekk]

One thing is that inverter is based on old type architecture with a huge iron transformer in there... ^^
Which will make noise esp. under heavy load in your house or if you connect rotary tools like drills, saws etc. etc.
That is why I f.ex. select to use hi-frequency inverters with electronic trafos which is less sensitive in these regards.
But, without more detective work/video with the sound f.ex. it is difficult to do long range fault searching.
Maybe some with more intimate knowledge of your inverter can help you on this forum.

My 2 cents.

 

[BentleyJ]

AS RCinFLA noted, its difficult to quantify the volume of the buzz. Based on the inverter readings you were only pushing 0.4 kW in scenario 1 and 0.25 in scenario 2. Based on my experience with the XW+ I would say the buzz is abnormal especially in scenario 2 with no utility AC and just the inverter operating at such a low output power.
That's not to say I've never heard the inverter hum but its usually with Peak Load Shave active, 2 AC coupled systems feeding in and all the air conditioning units on the same neighborhood transformer kicking on and off.

 

[LydMekk]

You said the noise stops when turning OFF the grid input fuse...sounds like a neighbour are putting noise on the grid.
Again the iron core trafo is sensitive to such.
So the issue might not be at your property at all.

 

[pvdude]

Mine were noisy, when I upgraded firmware to 1.11.01bn49, less noise, for mysterious Schneider reasons.

 

[RCinFLA]

When connected to AC input, once inverter synchronizes phase and matches AC input voltage, pass-through relay closes so the inverter runs in parallel with AC input. This is initially done open loop by inverter measuring AC input prior to pass through relay closing. Once relay closes it does small adjustments to refine matching.

For the least amount of current on inverter's transformer, which is usually least buzzing, the inverter's AC sinewave and AC input sinewave must match and overlap.

The buzzing is likely caused by overlap matching not being good enough. The PWM filter on inverter AC output creates a time delay in inverter's sinewave output. This is somewhat variable based on component make tolerances and must be calibrated out during factory adjustments. If this time delay 'fudge factor' is not set correctly the inverter will not precisely match AC input phase.

The inverter transformer may have a display readout on one of screens of SCP control panel of its temperature. With no AC output loads, you may want to check if the transformer temperature rises when connected to AC input. This may take 10-20 minutes to show up because of large mass of transformer. Check temp without AC input after 15 minutes, then check temp again with AC input connected, after another 10-20 minutes on AC input. If transformer temperature rises significantly with AC input and no AC output load, that is a problem with AC input phase/voltage matching.

First easy thing you can do is check AC input L1-N and L2-N AC voltage imbalance to rule it out as a cause. This is likely what Xantrex will tell you to do.

 

[JeffL]

I think your issue is different but I'll share this.

When I first set mine up and first turned it on it immediate went to making a terrible noise....so bad I quickly turned it off again.
Did this several times.

What I noted is that it was immediately charging the batteries from the grid and pushing the amps for that WAY up. I forget at what # of amps I stopped it by shutting it off but I recall it went to at least 100, maybe 120. I then reconfigured the charger setting "Maximum Charge Rate" to 50% and all was better.....it now pushes just shy of 70amps when grid charging and the audible sound is much less.

 

[RCinFLA]

A common and somewhat dumb thing many manufacturer's do, is default their charging bulk current to maximum or near maximum amount.

The very first thing you should do when first powering on a new hybrid inverter, before connecting to AC input, is to set up your desired charging parameters.

Also keep the charging setup power in mind when connecting to a generator. The inverter may jump on generator with an AC load current based on battery charging current setup, possibly overloading generator and immediately causing hybrid inverter to release from generator when it bogs down due to overload.

 

[mkimid]

If the noise is happening in Standby Mode, need to contact on Schneider.

I have got the similar issue with you,

Hum while always

http://www.bomijoa.com/files/se/se/IMG_1092.MOV

No hum while inverting (AC IN ON/OFF Both), just Humming while AC Pass Thru

http://www.bomijoa.com/files/se/se/IMG_1103.MOV

If just happening on Operation mode,
Check your firmware, if you are using V2.04_BN0029, it is the most terrible humming noise,

You should down grade to V1.11_BN0049 (https://solar.se.com/us/en/product/xw-pro-120-240v/#downloads)
or downgrade to V1.11_BN0028 (http://www.bomijoa.com/files/XW-Pro-6848-120-240V-Firmware-v1.11_BN0028.zip)

Much better than before, still some humming noise some time
BN0028 or BN0049 are similar on my case, and just just little better with BN0028

Try to find a noise source (in house -or- from grid), and if the noise is coming from the out side,
can reduce. but, can not remove completely. I have checked some noise status / ground status ... but, can not avoid 100%
While noise is happening, if turn-on bypass mode, noise will gone,

Even come back on normal operation mode, noise will not happening while,
I am pretty sure, the major source of noise is from inside of device itself.

Note 1, I have tested 3 devices, just little different level of noise,
Note 2, Plywood can amplify the vibration noise (device should be vibrating), I have relocated on the solid block wall, but can not be resolved,
the attached videos are taken while installed on 2/3" PLY WOOD which has installed 2x6 post in 8" spacing.
Note 3, I have running the device with very small resistive load (under 1kW) after removed all external load, yea, not difference.
Note 3, I am checking the load balancing with noise



Green N means, % of imbalance which has applied on inverter, I have tried to find a relationship between L1/2 imbalance and Hum noise, Unfortunately, not matched.

Anyway, I am looking for the noise source / cause also, if you find any improvement, I hope you are sharing for the other XW pro users.

 

[Andino2003]

Greetings, any news on the noise of your inverter because I have the same problem

 

[mkimid]

Greetings, any news on the noise of your inverter because I have the same problem

if the noise is not coming from your next door, there is no other solution except trying to use the different firmware such as v1.11_BN0028 or 49.