sine Inverter =>audio noise, erratic mouse behavior (rod grounding in the desert)

[ariel]

this is my first solar system.

145w, 24v panel
two 12v gel 40ah each
pwm controller
pure sine inverter 300w.

To the inverter I have connected a stereo pair of unbalanced speakers and my laptop (macbook pro retina)
both are connected thru a power extension which ground is connected to my house electrical grounding, this helps greatly to the noise however I still get noise in the speakers and some erratic behavior in the mouse of my laptop, (which occurs every once in a while)

I guess I would like to find a solution that fix both problems, I've been told that the issue could be in the low impedance of my house grounding and since I'll take this system to the desert of Atacama I'll try and independent GND rod for the system, any advices on this?
Also I've been told that I should take an additive to put in the ground since this land is not very conductive.

best

[jflorey2]

this is my first solar system.

145w, 24v panel
two 12v gel 40ah each
pwm controller
pure sine inverter 300w.

To the inverter I have connected a stereo pair of unbalanced speakers and my laptop (macbook pro retina)
both are connected thru a power extension which ground is connected to my house electrical grounding, this helps greatly to the noise however I still get noise in the speakers and some erratic behavior in the mouse of my laptop, (which occurs every once in a while)

Are the speakers powered? If so you are seeing a classic ground loop. Ferrites on the power line(s) may help. Using unpowered speakers would be a better solution.

Better system grounding will generally not help the above problem, because the problem is between three components - not between the component and another (ungrounded) component.

[Sunking]

To the inverter I have connected a stereo pair of unbalanced speakers and my laptop (macbook pro retina)
both are connected thru a power extension which ground is connected to my house electrical grounding, this helps greatly to the noise

Who told you that line of BS. Ground has nothing to do with it. The problem is your PWM Charge Controller and PWM Inverter. Remove the ground as it does nothing and serves no purpose except to make the noise problem worse.

Easy fix is to just get a good True Sinewave Inverter, then use power only from the Inverter. No Ground required and is only asking for trouble.

[ariel]

thank you Jflorey2
the speakers are active, so the speakers have its amplifier built in.

I've been looking at this post which seems to have the same problem as I do (even using a sine inverter as I do), we finally fix it by using an EMI filter connected to earth.
today I'll try both ferrita and filter solutions.

https://www.solarpaneltalk.com/forum/off-grid-solar/off-grid-solar-panel-systems/7698-i-get-an-audio-buzz-on-the-hifi-even-with-pure-sine-wave-any-advice

thank you!

[ariel]

Thanks Sunkin.
I don't have a PWM inverter, I have a true sine inverter (at least it what is claims) still I have found people with the same noise issue using apparent true sine inverters

https://www.solarpaneltalk.com/forum/off-grid-solar/off-grid-solar-panel-systems/7698-i-get-an-audio-buzz-on-the-hifi-even-with-pure-sine-wave-any-advice

GND actually help the noise to decrease greatly however I still have some which I want to get rid of.

[Mike90250]

Sadly, you may have bought unsuitable components for your system, either from ignorance (curable) or dishonest salesmen, First step is to replace the cheap inverter that you are using, with a high quality inverter like the Morningstar Suresine, It's power of 300w is a good match for your too small batteries, Eventually, you will have too replace the GEL (un-suitable for solar use) batteries, and you should get an AGM battery instead,
A good inverter should help quite a bit, you are wanting high quality performance, you won't get it from a junk inverter.
Any remaining noise in the daytime is directly attributable to the PWM controller.

erratic mouse behavior would have nothing to do with solar.

A grounding rod is not likely to help, but it may make you feel good.

[ariel]

thanks Mike, thanks for the advice!
I replaced the inverter with a professional victron 375w inverter and voila.

I'm still impressed how people can sell fake products, pseudo pure sine inverters, no inducer, fake mppt controllers which I also bought while ago.
anyways the noise from the speakers and the erratic mouse behavior dissapeared without removing my pwm controller. fortunately today I got a good deal for a real mppt so I got it and i'll use this one instead.

thank you!

[inetdog]

thanks Mike, thanks for the advice!
I replaced the inverter with a professional victron 375w inverter and voila.

I'm still impressed how people can sell fake products, pseudo pure sine inverters, no inducer, fake mppt controllers which I also bought while ago.
anyways the noise from the speakers and the erratic mouse behavior dissapeared without removing my pwm controller. fortunately today I got a good deal for a real mppt so I got it and i'll use this one instead.

thank you!

One problem is that people first learn the difference between MSW and PSW inverters and then think that everything they encounter will be one or the other and that there will be little difference within each group.
You can produce an MSW inverter that has a basic modified square wave output waveform but with controlled rise and fall time and no spikes or glitches in the waveform, or you can get one with sharp edges, overshoot and lots of high frequency noise energy.
On the PSW side you can get a good approximation of a sine wave output by using a pulse width modulator to produce the voltage at any time and then filter out the pulse edges as much as possible. Or you can use analog circuitry to produce smooth AC in a sine wave pattern.
There is a smooth progression from worst to best in MSW, then a big jump, and then a smooth progression from worst to best within PSW.

[Mike90250]

I'm glad it clean up and work for you,

[Sunking]

GND actually help the noise to decrease greatly however I still have some which I want to get rid of.

Ground has absolutely nothing to do with your noise. You are wasting your time chasing that ghost.

An Inverter is a Separately Derived System which removes any and all Common Mode Noise and Differential Noise. A 12 volt Inverter system has no requirement for any ground and doing so can only do one possible thing, make your problem worse.

Bet you a dollar if you plug your sound system into a standard AC circuit all your noise problems go away. If it does proves your Inverter is the source of your noise. Only other thing it can be a known problem is PWM Charge Controllers. So two real simple test. Disconnect the PWM controller, and power your sound system from AC power. Child's play to find the problem. It has nothing to do with ground.

[inetdog]

Ground has absolutely nothing to do with your noise.

+1

But bonding might.