Flickering lights when fridge runs?

[EngNate]

First, 'True'/'Pure'/'Sine' all same, not dismissing that some can claim a more pure or true sine wave than others, but it doesn't matter, it's a sine wave. You've likely never considered the waveform distortion spec for your generator - it isn't perfect. 'Modified Sine' is a term chosen for marketability, these are actually modified square wave. This is a big improvement over the earlier pure square wave, in fact there isn't much out there that won't run just fine on it.

The latest definitely sounds like the Xantrex unit is not handling the inductive loads. I have to concur with opinions up the thread about Xantrex, take it back and get a Magnum or Outback. I think the Magnum remote is a little more user friendly than the Outback. I give both of them an excellent reputation over years of experience.

 

[LeoKa]

First, 'True'/'Pure'/'Sine' all same,

The latest definitely sounds like the Xantrex unit is not handling the inductive loads. I have to concur with opinions up the thread about Xantrex, take it back and get a Magnum or Outback. I think the Magnum remote is a little more user friendly than the Outback. I give both of them an excellent reputation over years of experience.

Yes, I am at the point, where I would like my money back. Unfortunately, it will not work. The vendor which sold it to me, cannot take it back, since the original unit was replaced by Xantrex. No exchange either.

The support guys at Xantrex tried to figure out what the problem can be, but there is no luck so far. After the warranty replacement, they told me it could be the wiring from the batteries to the inverter. It was a 6 awg cable with Anderson plugs. I replaced all cables with 1/0 awg and new Anderson plugs. All these connect to a 1000A bus bar, which has a 4/0 cable to the inverter. So, the cabling cannot be blamed anymore.
Just yesterday, I had a higher up support guy from Xantrex and he made me measure the voltage from the batteries, which was 13.43V. It should be good enough, I think. 4 lithium batteries with 170AH/each should provide enough juice.
Interestingly, the flickering only occurs within a certain load range. The fridge’s load is about 180 watts, the freezer is about 150 watts. Total is between 320-350 watts and the flickering is still there. If I add another load, say something above 2-300 watts, the flickering stops and it is all good. So, something happens above 4-500 watts load, when the inverter becomes stable and the flickering stops.
Just discovered another issue yesterday. Last week, we had few hot days in the area, so it was hot in the boat. The temp around the inverter was between 80-90F, so the cooling fan was coming on over and over. At least, I thought it was the temperature. The weather cooled down over the weekend, but the cooling fan was still coming on every 5 minutes. The fan runs for about 30-40 seconds and turns off. The temp next to the inverter was 70-75F. So, the temp could not have affect on the unit. When I checked the display on it, I could see that the incoming shore power shows 128V, when the cooling fan runs. Can this be the reason for the constant cooling trigger?
I plan to measure the voltage at the pedestal on the dock and at the incoming wires soon. Right now, I turned off the shore power and let the batteries provide the house with electricity. Surprisingly, the cooling fan does not come on, when it is on battery only. I will wait for another hot day, to see, if the cooling behaves, or will it start the on and off game again?
So, I am not happy now and I am afraid that I am stuck with this unit. Even if they replace it again, which is unlikely, Xantrex will not refund my money, so I can buy another brand.

 

[EngNate]

Before you give up on it, you might try one of these: AC Line Noise Filter on the possibility that filter-able interference is causing the problem. Install it between the inverter AC output and the distribution panel. This is a 30 Amp model. It will only cost you about 40 bucks to try it, and this outfit is fast.

If the refrigeration units are new they will have electronic compressor drives than may feed back noise into the AC line, interfering with the inverter. Otherwise, it is a design flaw, the inverter is not able to handle the reactive loads i.e.- stuff with motors. The severity is directly related to the proportion of reactive load in the total, that is why turning on additional items, especially heating devices, makes the issue go away. The tech support people are not engineers and would be at a complete loss in this case.

 

[LeoKa]

Before you give up on it, you might try causing the problem. Install it between the inverter AC output and the distribution panel. This is a 30 Amp model. It will only cost you about 40 bucks to try it, and this outfit is fast.

The tech support people are not engineers and would be at a complete loss in this case.

Yes, I have that feeling that the support guys are not engineers. Although, they said they did describe the situation to their engineers. Who knows?

My board is upgraded to 50A. The shore power connection, too. I suspect, I need to get a 50A version of the filter? I looked at your recommendation and all 50A kind are 250V. Does it matter for a 120V inverter?
As you can see, I am not an electrician, so all those options on the web site are not very clear to me. I do not know how sort out the one I need? Please, advice.

 

[EngNate]

What size wire goes from the inverter AC output to the distribution panel? 10 AWG, use the 30 Amp filter.

Price jumps to about $100 for a 60 Amp unit (different supplier, also a good one). You might instead get one or two of the 30A ones and install at the panel for the circuit(s) with the offending appliances. 15A filters are cheaper but don't offer screw-terminal connections. There are hundreds of AC power line filters offered that would all be suitable as long as the rated voltage and current equals or exceeds the intended use.

 

[STB]

I think you mentioned getting a basic scope. Can you post the waveforms?

 

[LeoKa]

I think you mentioned getting a basic scope. Can you post the waveforms?

I will. Possibly this weekend.

 

[LeoKa]

What size wire goes from the inverter AC output to the distribution panel? 10 AWG, use the 30 Amp filter.



Price jumps to about $100 for a 60 Amp unit (different supplier, also a good one). You might instead get one or two of the 30A ones and install at the panel for the circuit(s) with the offending appliances. 15A filters are cheaper but don't offer screw-terminal connections. There are hundreds of AC power line filters offered that would all be suitable as long as the rated voltage and current equals or exceeds the intended use.

The AC cable is 6AWG/3 marine grade and brand new.

Nothing is free, so I might as well spend more money and protect all AC circuits, as you have suggested to install the filter between the inverter and the switch board.
It would be easier for me to install, as the AC cable is easy to reach at that section. A filter with easy mounting option is the best for me.
I will get this 60A model you have suggested.

 

[LeoKa]

I think you mentioned getting a basic scope. Can you post the waveforms?

Here are the pictures. My engineering friend set it up and there is no noise in his opinion. See photos.

 

[LeoKa]

I think we have narrowed down the source of the problem. It is the inverter.
The troubleshooting people at the manufacturer support asked me to do some tests. This weekend I was able to do it.

1/ Using my Magnum inverter/charger, I’ve connected the A/C wires to it, using old lead acid batteries. No shore power.
No flickering

2/ Using my Magnum inverter/charger, I’ve connected the A/C wires and used my new Lithium battery. No shore power.
No flickering

3/ Using the new Xantrex Pro Marine 3000 inverter/charger, no shore power, with new Lithium batteries.
There is flickering.

Prior these tests, we went through all receptacles and checked for wiring and ground issues. Couple of them had to be replaced. As of now, all check out normal.

This narrows it down to the inverter.

 

[tiltrider1]

I suspect the issue is the sine wave. I think xantrex pulled a fast one. They have tricked you into thinking you bought a pure sine wave inverter when in fact they are selling a modified sine wave inverter.

I bought a xantrex 40a battery charger as a back up charger. I went to test it the other day and what do you know it didn’t work. Even though it is still under warranty I replaced it with a Victron unit. The Victron unit is 4x bigger and has cooling fans. The lugs are 3/8 instead of 1/4. Yes it cost more but it is obviously a better piece of equipment.

 

[STB]

Here are the pictures. My engineering friend set it up and there is no noise in his opinion. See photos.

View attachment 118490

That is the waveform from the inverter? Yuck. That is anything but a smooth wave form. It isn't a square, nor a step wave, or a sine wave.

To me it looks like a sine wave with a ton of noise, although probably not enough to matter much for most things. I just don't know if that noise is internal, e.g. by design or failure is noisy, or external, e.g. coming from a load. In any case, personally, I wouldn't be happy with that.

Is that with a load or with no load? Breakers on or off? It probably makes sense to check with no load.

If your friend can, have him set the scope to filter the 60hz out and see what that noise signal looks like. It looks very periodic to me. If that scope will do it, a spectrum analysis would be nice, e.g. PSD. I'm wondering if we can sort what it is?

For reference, here is my old Xantrex ProSine 2.0 inverter, my old 1970s era Kohlet generator, and shore power under an every day house load. Can you tell them apart?

I didn't take the pictures, but my new boat and new equipment looked every bit as clean.

 

[LeoKa]

looked every bit as clean.[/QUOTE]


My pictures were taken under load. The flickering fridge was running at this time. No shore power. Only inverted battery power.
The scope was connected to a surge protected extension cord, together with the fridge. (It is impossible to connect the scope to the wall panel, due to limited access.) So, this is not pure inverter image only. Live and load connection.

I will tell my friend your observations and try to replicate your setup.

 

[STB]

Yeah. I am really curious if the inverter output, itself, looks like that, or if something else, e.g. the refrigerator, is doing that to it.

If a device is doing that, I could stretch to imagine it confusing an inverter.

That wave is just not one I'm used to seeing coming from an inverter. And, I'm having a hard time imagining a device that would cause that. Even florescent light ballasts don't make that much of a mess, although maybe one going bad. I just don't know.

I am curious what you find!

 

[LeoKa]

Guys. The only reason I have posted the scope pictures, because someone asked for it.
My problem is the flickering fridge. Not the scope. If there is a way to use the scope to prove it to the manufacturer the faulty inverter, that is all need it for. If not, we can forget about the scope and its images.
I need to prove to Xantrex that even the newly replaced inverter is not programmed properly for my boat, or the fridge/freezer I am using.

 

[STB]

If you get that waveform with no load, I think the inverter is bad (Faulty or poorly designed). Send the picture of the waveform to Xantrex and see what they say!

If it needs a load, then use a purely resistive one, like an old school incandescent light bulb.

 

[sbman]

Here are the pictures. My engineering friend set it up and there is no noise in his opinion. See photos.

View attachment 118490

Guys. The only reason I have posted the scope pictures, because someone asked for it.
My problem is the flickering fridge. Not the scope. If there is a way to use the scope to prove it to the manufacturer the faulty inverter, that is all need it for. If not, we can forget about the scope and its images.
I need to prove to Xantrex that even the newly replaced inverter is not programmed properly for my boat, or the fridge/freezer I am using.

The waveform is terrible, and certainly not a 'pure sine' wave. I would also keep a close eye on the peak-peak voltage, I expect it is changing from 40-60 V and then jumping to the proper 120V (will be greater than that to get 120 RMS), which is what the inverter will do to detect a load. My theory is, it's outputting it's 'sense voltage', detecting a load, jumping to 120V, but then determining that there isn't a load and dropping back to down 40-60V and then repeating that cycle over and over again. If you put a bigger load on it, that ends the cycle and it stays at full voltage the whole time. You'll have to play with the triggering to see that jumping around of the voltage or if it can sample, you can record the change.

A sample of the waveform when it isn't flickering would be an interesting comparison, and a good question for Xantrex, if they are significantly different, then why?

 

[Comodave]

Here are the pictures. My engineering friend set it up and there is no noise in his opinion. See photos.

View attachment 118490

Sure looks like a lot of noise to me. Check the other photos in post #42 of the wave forms, those look good.

 

[LeoKa]

If you get that waveform with no load, I think the inverter is bad (Faulty or poorly designed). Send the picture of the waveform to Xantrex and see what they say!

If it needs a load, then use a purely resistive one, like an old school incandescent light bulb.

The inverter does need a load to provide 120V. The scope picture is when the fridge was running. The inverter’s display also shows fluctuating voltage up and down.

Yes, I will send them the photo, too.

 

[LeoKa]

The waveform is terrible, and certainly

A sample of the waveform when it isn't flickering would be an interesting comparison, and a good question for Xantrex, if they are significantly different, then why?

The starting load to trigger A/C inverting is 25W. When the fridge runs, it draws around 180W. If the load reaches over 200-220W the A/C becomes stable and no flickering occurs.

 

[sbman]

The inverter does need a load to provide 120V. The scope picture is when the fridge was running. The inverter’s display also shows fluctuating voltage up and down.

Yes, I will send them the photo, too.

That's your flickering right there. You should be able to capture the voltage going up and down with the scope and send that to Xantrex, there's no question that isn't right.

 

[STB]

For another reference, here are the waveforms from shore power and my Xantrex Freedom HFS 2000, each under load including at least a countertop ice maker. These are from tonight. Again, this is what I'd expect to see. And, if not, I'd want to isolate it to the inverter (most likely case) and get Xantrex to fix it, or isolate it to other specific load(s) and address them.

This, and my earlier post, are the same brand as yours, even if eqch different models. I thinkntheyd find it hard to explain the difference as being correct. I hope.

 

[phillippeterson]

Looks like the lack of accountability from Xantrex will remove them from my list of companies to buy an inverter from.

 

[LeoKa]

These are from tonight. Again, this is what I'd expect to see. And, if not, I'd want to isolate it to the inverter (most likely case).

It is isolated down to the inverter I have.
This happens only when the inverter provides A/C and the fridge, or freezer is running. Nothing else.
The tech support is trying to find a solution, but they say, it was already replaced once, so it is not possible that two units are faulty. They insist that the problem is on my boat.
My tests from this weekend suggest otherwise. My Magnum inverter with the same setup, does not cause any issues. Either from lead acid, or lithium batteries.
I will continue calling them.

 

[Nick F]

As regards visualizing the flickering, may I suggest that you take a scope shot with about 100 cycles on the screen (instead of 4). This should show the voltage fluctuation.

As regards the noisy sine wave which you showed us, I agree with our fellow poster who asked to see a scope shot with a purely resistive load (baseboard heater).

Some bigger industrial inverters have something called an output filter - basically a combination of a coil and a capacitor - used to smooth the waveform. Your waveform, although noisy, is indeed basically a sine wave. It is nothing like a square wave, or "modified" square wave (see attachment).

 

[LeoKa]

Looks like the lack of accountability from Xantrex will remove them from my list of companies to buy an inverter from.

I totally agree with you.
Let me update you guys about this story.
I bought this unit in March and they replaced it in April. They made do all kind of troubleshooting. No luck. Finally they asked me to test another inverter with the fridge, or other type of batteries, just to see, if the flickering will go away. So, I did. I used my old Magnum and I also tested with flooded batteries. The Magnum did not cause flickering. The lead acid batteries did not make any difference comparing to the lithiums. The flickering with the Xantrex was still there. It was obvious that the Xantrex unit was the problem.
So, in August they agreed to refund my money, if I send the unit back. It took them a while to issue the RMA, but they’ve got the inverter back at the beginning of September. Again, the refund was approved by the management.
As of today, I still don’t have my money back and everybody is ignoring me. I have sent many emails, called many times. All I am getting is the ‘ we will get back to you, let me check with so and so… ‘.
I really don’t know what else to do to get my money? Very, very frustrated!

 

[BruceK]

There is no issue they owe you the $, or the amount. So you can sue and win, but that`s expensive, unless you have a DIY Consumer/Small Claim Tribunal.
I went through something similar with Garmin here, after buying 2 GPS/Sounders they said could run off one transducer when they could not. Some senior guy got involved and a brick wall went up, he thought I`d "invented" the Garmin advice I relied. I sent Garmin USA a letter asking for help, cc to Garmin Sydney who were holding my GPS unit they were checking. After that, for some reason, Garmin Sydney could not have been more helpful.

 

[sunchaser]

KT

You've been resolute on your vessel upgrades, congratulations.

Three things:

First - In post #12 your picture showed Xantrex. That strongly suggested to me the problem was the manufacturer with sporadic brand specific problems going back over a decade.

Second - my 9 year old Magnum started acting up this past summer with some electronics affected. The instrument tech/store said they consider inverters ( they've installed hundreds over the years) throw away items as trouble shooting is hit and miss, expensive and time consuming. A new inverter was installed and life is good.

Third - Sadly, no inverter brand is immune from difficulties. Xantrex (I once had one) seems more trouble prone. Why did you not go with a new Magnum Vs the Xantrex?

 

[LeoKa]

Third - Sadly, no inverter brand is immune from difficulties. Xantrex (I once had one) seems more trouble prone. Why did you not go with a new Magnum Vs the Xantrex?[/QUOTE]


Good question.
After my pure sine Magnum died due to an unavoidable water damage, I bought another Magnum. It was working fine , but was too noisy at night. Magnum supports’s help was not really understanding and practically told me to live with it, by saying all inverters make noise. Interestingly, the one which died did not make any significant noise. By the way, the buzzing noise could be reduced significantly, if the transformer’s mounting screws were loosen a bit. So I was not happy with Magnum.
I also had a plain battery charger from Xantrex for worldwide voltage, which worked pretty well. So I figured I’d would Xantrex a try. I was also in the process of moving to lithium batteries and my Magnum did not have settings for that. I still have the Magnum, which I actually used to prove to Xantrex that my fridge flickering only happens with their product.
The rest of the story is in the threads.

 

[sunchaser]

Quote [I was also in the process of moving to lithium batteries and my Magnum did not have settings for that.] Unquote

Last time I checked (past summer) Magnum Inverters now have LiFeP battery pre-sets.