13 hours ago, Olorin said:

Okay so I buy this gadget and then what? I'm not technical, so what am I to do then? 

I have no idea where @frivan comes with his buck converter idea.  You say it is the AV.  So that would mean something like a Denon / Sony / Yamaha 7-channel or whatever unit?   Each channel is most likely rated at a minimum of 50Wrms or so, meaning the AV receiver will have a few hundred watt power supply with plus and minus 40-50VDC supply lines and many other voltages as well.

Your AV should have no problem at all.  We had a discussion a few days ago about an AV constantly blowing it's fuse.  This was on another Axpert inverter, not the Kodak.  I can't find the link to that discussion now.  Anyway, the speculation is that the inverter creates a DC voltage for a moment during startup.  AVs mostly use 50Hz power transformers that would saturate when presented with DC.  Your TV, lights, laptops, etc. all use switch-mode power supplies and would not be effected.

I don't know at what frequency the various switch-mode power supplies of an Axpert run.  It should be >20Khz, but even SunSynk was so dumb to run their switchers at 15Khz (apparently now increase to 20Khz with a firmware update).  The buzzing noise you hear is normally from magnetic components such as chokes, inductors and transformers where the enameled copper wire turns are not properly covered with varnish, RTV (silicon) or potting resin and then vibrate at the switching frequency.

Even if the switching frequency is >20Khz it might still make noises due to beat frequencies.  This would occur if two smps run unsynchronized and at slightly different frequencies.  For instance one runs at 20 and another at 21Khz.  This could produce a beat frequency of 1 Khz (the difference).

All the above problems (momentary DC, under 20Khz switching and beat frequencies) should NOT happen in a properly engineered product.  But if a much more expensive SunSynk can't get things right, then there is not much hope for cheaper Axpert systems, especially clones.  (Your Kodak is not a clone).

The AV having a hickup is worrying.  I also have an AV but never switch it on during L/S.  These receivers most likely have a minimum consumption of maybe 70W at low volume settings...  quite wasteful when you run on batteries.

If the DC theory is correct, any electronic and even electro-mechanical device with 50Hz transformers and motors could give problems.  Devices with small 50Hz transformers could be damaged.  Larger transformers as used in AVs are less likely to get damaged, but are likely to blow fuses.

 

Edited April 25, 20233 yr by Modina

6 hours ago, Modina said:

I have no idea where @frivan comes with his buck converter idea.  You say it is the AV.  So that would mean something like a Denon / Sony / Yamaha 7-channel or whatever unit?   Each channel is most likely rated at a minimum of 50Wrms or so, meaning the AV receiver will have a few hundred watt power supply with plus and minus 40-50VDC supply lines and many other voltages as well.

Your AV should have no problem at all.  We had a discussion a few days ago about an AV constantly blowing it's fuse.  This was on another Axpert inverter, not the Kodak.  I can't find the link to that discussion now.  Anyway, the speculation is that the inverter creates a DC voltage for a moment during startup.  AVs mostly use 50Hz power transformers that would saturate when presented with DC.  Your TV, lights, laptops, etc. all use switch-mode power supplies and would not be effected.

I don't know at what frequency the various switch-mode power supplies of an Axpert run.  It should be >20Khz, but even SunSynk was so dumb to run their switchers at 15Khz (apparently now increase to 20Khz with a firmware update).  The buzzing noise you hear is normally from magnetic components such as chokes, inductors and transformers where the enameled copper wire turns are not properly covered with varnish, RTV (silicon) or potting resin and then vibrate at the switching frequency.

Even if the switching frequency is >20Khz it might still make noises due to beat frequencies.  This would occur if two smps run unsynchronized and at slightly different frequencies.  For instance one runs at 20 and another at 21Khz.  This could produce a beat frequency of 1 Khz (the difference).

All the above problems (momentary DC, under 20Khz switching and beat frequencies) should NOT happen in a properly engineered product.  But if a much more expensive SunSynk can't get things right, then there is not much hope for cheaper Axpert systems, especially clones.  (Your Kodak is not a clone).

The AV having a hickup is worrying.  I also have an AV but never switch it on during L/S.  These receivers most likely have a minimum consumption of maybe 70W at low volume settings...  quite wasteful when you run on batteries.

If the DC theory is correct, any electronic and even electro-mechanical device with 50Hz transformers and motors could give problems.  Devices with small 50Hz transformers could be damaged.  Larger transformers as used in AVs are less likely to get damaged, but are likely to blow fuses.

 

Thank you for the reply. Regarding the buzzing sound, why is it that it goes away entirely when only running on battery power but yet on Eskom power I have the buzzing? That's what I don't understand.

Regarding my AV receiver turning off and then on again, so I have a Marantz AV receiver. On the mybroadband forums there was a guy who has an Onkyo AVR and he tells me the same thing happens on his when load shedding hits. I was just hoping there was a way to get around this - some people say I should get a UPS, the off/on again issue is going to be a problem long-term I think.

I bought my inverter and batteries to run my AV, otherwise what's the point? Just run lights and fridge? I spent a good deal of money (for me, anyway, if R40K is anything). I just don't like it when the amplifier switches off and on again, so if there is a fix to this I'm all ears.

Edited April 25, 20233 yr by Olorin

7 hours ago, Modina said:

21 hours ago, Olorin said:

Okay so I buy this gadget and then what? I'm not technical, so what am I to do then? 

I have no idea where @frivan comes with his buck converter idea.  You say it is the AV

Sorry, my soundbar has a DC input. I assumed it was some small DC powered unit.

2 hours ago, Olorin said:

Regarding the buzzing sound, why is it that it goes away entirely when only running on battery power but yet on Eskom power I have the buzzing? That's what I don't understand.

I agree that this is a bit odd, but note that an Axpert inverter has at least 2 high power converters and the high power inverter.  Additionally there will be a handful of low power SMPSs to supply power to all internal circuits.  Further, there will be a number of high power filters such as common-mode input filter, output chokes and likely another common-mode filter on the output.  It could be any of these wound components.

 

2 hours ago, Olorin said:

Regarding my AV receiver turning off and then on again, so I have a Marantz AV receiver. On the mybroadband forums there was a guy who has an Onkyo AVR and he tells me the same thing happens on his when load shedding hits. I was just hoping there was a way to get around this - some people say I should get a UPS, the off/on again issue is going to be a problem long-term I think.

 

I mentioned that other AV receiver that blows fuses...  Yours doesn't, but it drops out.  So this is not a DC problem.

Please first ensure that your setting <3> is set to UPS and not to APL.  In UPS mode the transfer takes about 10mS while in appliance mode the transfer takes twice as long.  My own Axpert uses APL as the default mode, chances are yours might too.

My guess is that your AV receiver doesn't like the short blackout period when 230VAC drops away and the inverter is enabled.  Even a 500mS blackout should be OK for the individual amplifiers because of large bulk-storage capacitors in the power supply.  What I suspect is happening is this:

Many AV and HiFi amplifiers have elaborate speaker protection circuitry.  This consists of a power-on de-thumb protection, a switch-off de-thumb and a DC offset protection.  At power-on and power-off state changes, the amplifier goes through an unstable phase which can cause loud thuds in the speakers.  Not only unpleasant but no good for the speakers either.  So in a stereo amp the speakers are switched through a relay.  Not sure if relays are used in AV amps, because there are so many extra channels in AVs.  Anyway, this protection circuit is rather quick as it wants to switch the speakers off before the bulk-storage capacitors in the PSU discharge.  In other words, on the first indicator of a power blackout this circuit might trigger.  At switch-on, or in this case when power is re-established, the circuit is designed to keep the speakers off for a number of seconds (normally 2 or 3s) , to allow the amplifier to stabilize it's various DC operating points.

In a HiFi amp you would hear the relays click.  As I said, not sure if AV amps use relays, they might use other circuitry such as FETs at their inputs or some other technology.

If the above hunch is correct, this would not be damaging in any way.  But it is very obstructive.

There is no easy solution for the end-user.  If it was my amp I would open it up and modify the protection circuit to not drop out that fast.  Adding a small capacitor in the base drive of the transistor that drives the protection relay might do it.    The problem is that AV amps are packed.  If one is unlucky, it could be a huge mission to strip various boards to reach the protection circuitry.  On HiFi amps this would likely be much easier because they generally have a lot of room and most use only a single main PCB.

What is the model number of your Marantz?  I think I might have some service manuals for AV amps.  From the circuit diagram one would get a good idea what type of protection is implemented and if it would be easy to do a mod.

The problems that people have with various systems misbehaving in some or other fashion when on inverters, never ceases to amaze me.

 

1 hour ago, Modina said:

I agree that this is a bit odd, but note that an Axpert inverter has at least 2 high power converters and the high power inverter.  Additionally there will be a handful of low power SMPSs to supply power to all internal circuits.  Further, there will be a number of high power filters such as common-mode input filter, output chokes and likely another common-mode filter on the output.  It could be any of these wound components.

 

 

I mentioned that other AV receiver that blows fuses...  Yours doesn't, but it drops out.  So this is not a DC problem.

Please first ensure that your setting <3> is set to UPS and not to APL.  In UPS mode the transfer takes about 10mS while in appliance mode the transfer takes twice as long.  My own Axpert uses APL as the default mode, chances are yours might too.

My guess is that your AV receiver doesn't like the short blackout period when 230VAC drops away and the inverter is enabled.  Even a 500mS blackout should be OK for the individual amplifiers because of large bulk-storage capacitors in the power supply.  What I suspect is happening is this:

Many AV and HiFi amplifiers have elaborate speaker protection circuitry.  This consists of a power-on de-thumb protection, a switch-off de-thumb and a DC offset protection.  At power-on and power-off state changes, the amplifier goes through an unstable phase which can cause loud thuds in the speakers.  Not only unpleasant but no good for the speakers either.  So in a stereo amp the speakers are switched through a relay.  Not sure if relays are used in AV amps, because there are so many extra channels in AVs.  Anyway, this protection circuit is rather quick as it wants to switch the speakers off before the bulk-storage capacitors in the PSU discharge.  In other words, on the first indicator of a power blackout this circuit might trigger.  At switch-on, or in this case when power is re-established, the circuit is designed to keep the speakers off for a number of seconds (normally 2 or 3s) , to allow the amplifier to stabilize it's various DC operating points.

In a HiFi amp you would hear the relays click.  As I said, not sure if AV amps use relays, they might use other circuitry such as FETs at their inputs or some other technology.

If the above hunch is correct, this would not be damaging in any way.  But it is very obstructive.

There is no easy solution for the end-user.  If it was my amp I would open it up and modify the protection circuit to not drop out that fast.  Adding a small capacitor in the base drive of the transistor that drives the protection relay might do it.    The problem is that AV amps are packed.  If one is unlucky, it could be a huge mission to strip various boards to reach the protection circuitry.  On HiFi amps this would likely be much easier because they generally have a lot of room and most use only a single main PCB.

What is the model number of your Marantz?  I think I might have some service manuals for AV amps.  From the circuit diagram one would get a good idea what type of protection is implemented and if it would be easy to do a mod.

The problems that people have with various systems misbehaving in some or other fashion when on inverters, never ceases to amaze me.

 

Again, thank you for the time you took to reply. I feel bad as my response will be fairly short in comparison. I have a Marantz SR-5011 receiver. Regarding the inverter settings, I'm scared to even navigate the menu without an installer present as I fear I might accidentally mess something up, however if I read the manual for my Kodak it does indeed say that APL is the default setting.

My installer is coming around tomorrow morning as I see a exclamation mark flashing on my inverter and I'm not sure why - I'll ask him to change the APL to UPS and see if that has any effect on the receiver. Many thanks for your detailed reply.

Edited April 25, 20233 yr by Olorin

7 hours ago, Olorin said:

Thank you for the reply. Regarding the buzzing sound, why is it that it goes away entirely when only running on battery power but yet on Eskom power I have the buzzing? That's what I don't understand.

Because there are different sets of circuitry within any of these inverters.

One set will charge the batteries from the PV. Another will receive the grid supply and rectify it for charging batteries and, I'm guessing, for the inverter's own use. Another will take DC from the battery and convert it to AC that your home can use. 

The second that I mention isn't going to do much when there's no grid. Other circuits will come into play, notably the DC to AC conversion. 

So I would think that the noise is in that circuit that receives the grid power, and that that shuts down during load shedding, and that's why you don't hear the noise. 

Is it louder when the machine is working hard? Mine is usually as quite as a quite thing, but if I'm force charging the batteries from the grid and there's a some big loads running (pool pump & heat pump, say, then it hums just a little. 

7 hours ago, Olorin said:

Regarding my AV receiver turning off and then on again, so I have a Marantz AV receiver. On the mybroadband forums there was a guy who has an Onkyo AVR and he tells me the same thing happens on his when load shedding hits. I was just hoping there was a way to get around this - some people say I should get a UPS, the off/on again issue is going to be a problem long-term I think.

I bought my inverter and batteries to run my AV, otherwise what's the point? Just run lights and fridge? I spent a good deal of money (for me, anyway, if R40K is anything). I just don't like it when the amplifier switches off and on again, so if there is a fix to this I'm all ears.

Me no technical (was many years ago, but I didn't keep it up, and things have advanced a bit since I last poked around inside a cash register), but it occurred to me that this must be due to the time between grid going down and AC from the inverter being available. There is always a very short period during which there is no power. Mostly it's not a problem. But if that period gets too long then it may become a problem for some devices. Do you see anything flicker, anything briefly change the sound it makes? 

Anyway @Modinagave a very good explanation that took me back to the days when I had a Sansui amplifier that would seem to do nothing when you turned it on, then you'd hear a click & then it would be ready. So follow the advice he gave you and let's see if a faster transfer time is possible and that solves your problem.

I don't think it will get damaged. I recall from my college days that any solid state amplifier degrades each time it is turned on or off, but this is mitigated with negative feedback. As long as you don't get one of those nasty surges heading for the AV you should be OK. Surge protectors can be a good idea.

Low frequency hum is always 50 and 100Hz and yes that has a habit to increase during high loads.  But if the noise is described as a buzzing noise that would be much higher in the frequency spectrum.  There are many circuits that could interact.

I have seen many hi-res pictures of Axpert inverters and it doesn't seem as if any toroids (those things that look like mini donuts) are covered in any resin.  Normally such inductors are at least covered with some tape, but all I see is raw enamelled copper wire.

I feel that 10 or 14K is a lot of money for an inverter until I realize that even an entry level AV receiver will cost that and top models sell for 100K.  Then we don't even talk about real HiFi which has become eye-watering expensive.  All things considered, Axpert inverters are very good value for money.  No wonder that some corners are cut in QA.

Modina, just to let you know you were right! I set my inverter to UPS and it worked, no more shut downs. Thank you very much for the fix!!

If I come across other people who have this issue I'll be sure to let them know. 

Glad to hear that you can now listen to your music without stutter.
Sad that your inverter whistles during the interludes.🙉

33 minutes ago, Modina said:

Glad to hear that you can now listen to your music without stutter.
Sad that your inverter whistles during the interludes.🙉

Thanks! Well to be fair the high pitched hissing sound is only on Eskom power, on battery power its totally silent. I spoke to the suppliers and they gave me a technical explanation that I've already forgotten, but according to.him the buzzing/hissing is normal 

Edited April 26, 20233 yr by Olorin

13 hours ago, Modina said:

Glad to hear that you can now listen to your music without stutter.
Sad that your inverter whistles during the interludes.🙉

Sorry just one last question regarding the APL and UPS modes - are there any downsides or consequences that I need to be aware of if running in UPS mode? It's not going to damage my inverter or battery in the long term?  I'm just a little worried as I just splurged on this equipment a week ago, just want to make sure it's safe to do so.

Running in UPS mode will have no detrimental effects on inverter or battery. I am not sure why there is even this setting in the first place.  There must be a reason for giving an APLiance mode option, but I can't think of one now.

Noise on the power lines can look like a possible power loss event if the detection window is narrow because the instantaneous voltage of the sinewave is monitored and checked against the expected/theoretical voltage of the AC phase.   In APL mode the inverter looks over a slightly wider window to decide if a possible power loss event has occurred.  This wastes a few milliseconds of time.

Perhaps someone else can give a reason for when one would rather want to operate in APL mode.

Just an update on the system - system has been working very well over the past few weeks, but I have a problem. The battery indicator lights (there are 6 lights indicating 100% charge), only 4 of them are lighting up. When I first had the system installed 5 lights were on, I assumed the 6th light wasn't related to the battery, so I wrote that off, but when I spoke to Hubble today they tell me that all 6 lights should be on when the battery is fully charged.

My installer has checked settings and says everything is fine. I assumed the LED lights were maybe blown hence why they aren't lighting up, but if I switch the battery off and then on all 6 LED lights cycle through so the lights aren't faulty.

What the one Hubble expert told me is that I need to do a firmware update and that he reckon will resolve the issue. Has anyone performed that and is it easy to do? They said I need to get a RS232 to USB cable. They emailed me a link to firmware, it's like 450KB. My installer keeps telling me he's busy so I fear I might have to do this myself.

Any pointers?

Edited May 24, 20233 yr by Olorin