Inverter / Charger / Generator

[Biggles]

I am still finding problems with the generator / inverter / charger setup

 

If you have a look at the video what you can see is what happens when I have my oven running with the charger on. The first part of the video is just with the fan and light on without any heating element load, the second part is under load as well. The oven is 3kw, the generator is 6.5kw, the charger is 50amp pass through.

Video Link https://www.youtube.com/watch?v=LU6araPqqSw

 

When I look at this on the VE config the input voltage is jumping up to 251 volts which would account for the light flairing. The genny AVR is set to 235v no load.

 

Now the strange thing is, I can stop this surging happening if I do 1 of 3 things. If I switch over to weak AC it stops but then I lose about 20-25amps of charging, or if I leave it off weak AC but turn off the charging, or load the mains to over 3kw by turning on a fan heater so forcing the charger to switch off.

 

Clearly neither of the first situations is ideal as it requires the laptop to be connected each time I want to use the oven or I settle for having it on weak AC and losing the additional charge rate at other times. Nor is having a fan heater on just to run the oven.

 

Can you suggest a solution? I did think about feeding the oven direct from the generator or through AC2 but this also has problems if I simply want to use just the microwave part of the oven which can is easily done through the inverter from the batteries so no need to start the genny.

 

The oven will run quite happily through the inverter only with the engine providing charge to the batteries which is fine if we want to use it while cruising but of course if I have it on AC2 then again it would not get power. There is a slight discharge from the batteries of. The microwave side of things will work fine on the batteries alone.

 

On the video you can hear in the background a clicking at the end of the video. This is my dog walking around, nothing to do with the oven, genny or inverter.

 

While this flairing is anoying and clearly not right the result is a voltage surge to 250v which caused a sky box and DAB radio to burn out the power supply boards and the loss of 2 switch mode power supplies and a cordless drill charger. Not funny.

 

I have tackled Victron at length on this but they are blaming the generator. This I think is spurious as the generator puts out a steady 225v - 235v without the oven on and maintains 49-52 Htz.

 

IMO the charger side is the problem as reading the Victron live software read out the charge current jumps wildly between 40-50 to 70-90amps of charge this I guess causing the voltage flairs.

 

I hope I have explained this sufficiently.

[GUMPY]

Ignoring the readings on the victron what is the voltage doing at the generator measured with a digital meter or if its to quick for that with a scope?

[Biggles]

Ignoring the readings on the victron what is the voltage doing at the generator measured with a digital meter or if its to quick for that with a scope?

 

235v tested with a multimeter and one of those volt, amp, Htz watt plug things. All readings are extreemly close.

[by'eck]

When running oven on pass through, is the Victron Combi inadvertently using its inverter in any way to supplement the current draw from the oven?

 

If so I can see potential for fluctuation caused by inverter current draw from batteries loading the charger which then takes more AC input current. The hysteresis in this loop provided by the batteries would maintain the fluctuations. Give this scenario, the generator AVR may not react fast enough to avoid the high voltage surge.

[mrsmelly]

Ill think about this one be back in a minute......................blimey back already, just turned my gas oven on to finish my pudding off

now whats this thread about again...................

 

Tim

[GUMPY]

If the voltage is stable at the generator at all times the victron must be adding in the extra, is power assist on, on the victron?

One other thought does it do it when connected to a shore suppply of suitable size?

[Biggles]

When running oven on pass through, is the Victron Combi inadvertently using its inverter in any way to supplement the current draw from the oven?

 

If so I can see potential for fluctuation caused by inverter current draw from batteries loading the charger which then takes more AC input current. The hysteresis in this loop provided by the batteries would maintain the fluctuations. Give this scenario, the generator AVR may not react fast enough to avoid the high voltage surge.

 

 

I can't run it on AC2 without modification if thats what you mean by passthrogh. I understand passthough to be when the power demanded by the boat is more than the inverter can make. My inverter will pass 50 amps most just pass 16 amps. So if when I have the oven on and the fan heater this is more than 3000w and the inverter will call on the mains source in my case 28amps max. At this point the charger is switched off as there is not enough residule power to supply it. The charger is smart in that it only produces charge from "spare" mains input.

 

If the voltage is stable at the generator at all times the victron must be adding in the extra, is power assist on, on the victron?

One other thought does it do it when connected to a shore suppply of suitable size?

 

 

Not had the oppertunity ot try it on shore power since being on water. Power assiste is off.

[smileypete]

Sounds like the AVR in the genny can't cope with the victron. For a long shot is the UPS function of the victron enabled and does switching it off help? Any voltage/freq wobbles may cause it to start the switchover from charger to inverter which makes things worse until the AVR catches up.

 

Also IIRC you turned the genny voltage up, so maybe backing it off a bit would help. IF it's popping switched mode power supplies the voltage may be surging quite high for a small fraction of a second, as high as 280V or more.

 

cheers, Pete.

~smpt~

[bottle]

I understand pass though to be when the power demanded by the boat is more than the inverter can make.

 

I think it is the exact opposite.

 

When shoreline or generator are connected and working the inverter is in idle and the charger is 'on'. If the load is to large for shoreline or generator then (depending on settings) the inverter will supplement/assist.

 

Maybe reading the explanations of what each setting does on the Victron interface may help.

 

Good luck

[by'eck]

I can't run it on AC2 without modification if thats what you mean by passthrogh. I understand passthough to be when the power demanded by the boat is more than the inverter can make. My inverter will pass 50 amps most just pass 16 amps. So if when I have the oven on and the fan heater this is more than 3000w and the inverter will call on the mains source in my case 28amps max. At this point the charger is switched off as there is not enough residule power to supply it. The charger is smart in that it only produces charge from "spare" mains input.

 

Sorry, thought you knew that the Combi (combined charger/inverter) allows incoming AC to pass through the unit to the AC output terminals and on to your AC distribution system. There is a relay that controls the pass through, dropping out when there is no incoming AC and allowing the inverter to continue to supply AC.

 

Your Victron does have a selectable function to allow the inverter to supplement the incoming AC as well though, if there is not sufficient current to cover the load. That's what I was referring to.

[Biggles]

I think it is the exact opposite.

 

When shoreline or generator are connected and working the inverter is in idle and the charger is 'on'. If the load is to large for shoreline or generator then (depending on settings) the inverter will supplement/assist.

 

Maybe reading the explanations of what each setting does on the Victron interface may help.

 

Good luck

 

I still think the passthrough is how much total current the Victron will pass or if you like manage which is how I'm able to run an oven and a fan heater rated at 6kw or about 25amps of which the genny will all. If the load exceeds 3kw the charger is switched off, if the load exceeds the genny output the inverter starts to add the rest up to another 3kw so in my case the maximum draw would be about 38kw.

 

I do have the remote panel.

 

I have read the manual from start to finish many times and have a reasonable understanding of the settings, I have also been on to Victron several times for their support. The latter of which has resulted in the settings I currently have. Their customer service dept is 1st rate I have to say.

 

Sounds like the AVR in the genny can't cope with the victron. For a long shot is the UPS function of the victron enabled and does switching it off help? Any voltage/freq wobbles may cause it to start the switchover from charger to inverter which makes things worse until the AVR catches up.

 

Also IIRC you turned the genny voltage up, so maybe backing it off a bit would help. IF it's popping switched mode power supplies the voltage may be surging quite high for a small fraction of a second, as high as 280V or more.

 

cheers, Pete.

~smpt~

 

UPS is switched of. One of the first things Victron advised. I suppose a tweak down on the voltage might help but then it might set me back to where I was where the weak AC was the only way to get the charger to work.

 

I have not seen voltage spikes that high on the Victron readout but guess its to quick to register.

 

Is there some sort of device that could smooth out this problem?

[pearley]

 

I have tackled Victron at length on this but they are blaming the generator. This I think is spurious as the generator puts out a steady 225v - 235v without the oven on and maintains 49-52 Htz.

 

 

But what happens to these figures once you put a load on. My Vetus 6.5 kva generator, a 3000rpm unit like yours, was fine like this with no load but would drop down to 46 Htz with the oven on. We ran the Victron on weak AC from day one as it was the only way the washing machine would work. The lower charge rate didn't worry us as we moved regularly to charge the batteries.

 

However, the Vetus genie was so unreliable, besides being noisy, that we bit the bullet and replaced it with an Onan and now have no problems and a quieter life.

 

Regards

Pete

[nb Innisfree]

I still think the passthrough is how much total current the Victron will pass or if you like manage which is how I'm able to run an oven and a fan heater rated at 6kw or about 25amps of which the genny will all. If the load exceeds 3kw the charger is switched off, if the load exceeds the genny output the inverter starts to add the rest up to another 3kw so in my case the maximum draw would be about 38kw.

 

The Victron doesn't 'manage' the incoming power as such, the pass through is done via a relay that's all, a bit like where instead of traffic being directed, or managed, through a town, instead it's diverted to a bypass road but a feeder road from the town allows traffic from there to join the bypass and add to the total traffic flow.

[smileypete]

If the victron is using pass thru can it be turned down so it reduces or stops charging if the oven is being used?

 

Maybe the genny or it's speed governor can't hold the freq to what the victron needs, and the avr can't cope with the charger side of the victron kicking in and out, which will also make it harder for the genny and speed governer to hold a constant freq when the load is constantly changing.

 

cheers, Pete.

~smpt~

[nb Innisfree]

Victron can only divert the incoming power to the consumer unit, it will try to mimic the waveform of that incoming power and add to it at a certain point, that point is determined by what incoming amperage limit the Victron has been set to, when that happens charging is obviously abandoned. As I understand it charging is either switched on or off, no reduction or increase other than the usual bulk, absorption, float.

[Biggles]

But what happens to these figures once you put a load on. My Vetus 6.5 kva generator, a 3000rpm unit like yours, was fine like this with no load but would drop down to 46 Htz with the oven on. We ran the Victron on weak AC from day one as it was the only way the washing machine would work. The lower charge rate didn't worry us as we moved regularly to charge the batteries.

 

However, the Vetus genie was so unreliable, besides being noisy, that we bit the bullet and replaced it with an Onan and now have no problems and a quieter life.

 

Regards

Pete

 

 

So far for us the genny has been very reliable. 2400 hours now of which I've added about 10%. The frequency never drops below 49htz and the genny governs with load gradually.

 

On that I forgot to say the flaring doesn't start immediately it builds to that after about 30 seconds. It starts as a slow pulse.

 

I suppose when we cruise more it might be ok to stay on weak AC. But we will still want to use the oven with the genny at times.

 

Victron can only divert the incoming power to the consumer unit, it will try to mimic the waveform of that incoming power and add to it at a certain point, that point is determined by what incoming amperage limit the Victron has been set to, when that happens charging is obviously abandoned. As I understand it charging is either switched on or off, no reduction or increase other than the usual bulk, absorption, float.

 

It charges to the amount of spare AC available. This I know as I've seen it on the Victron Software display.

Edited January 6, 2013 by Biggles

[nb Innisfree]

So far for us the genny has been very reliable. 2400 hours now of which I've added about 10%. The frequency never drops below 49htz and the genny governs with load gradually.

 

On that I forgot to say the flaring doesn't start immediately it builds to that after about 30 seconds. It starts as a slow pulse.

 

I suppose when we cruise more it might be ok to stay on weak AC. But we will still want to use the oven with the genny at times.

 

 

 

It charges to the amount of spare AC available. This I know as I've seen it on the Victron Software display.

 

Yes that's true, what I'm trying to say is when the the Victron reaches the preset input amperage limit and then goes into power assist it abandons charging, i.e. it doesn't have the ability to sense an increased load on the mains circuit and then adjust the charge rate, it will try to charge at whatever power has been preselected even if it overloads the generator.

[Biggles]

Yes that's true, what I'm trying to say is when the the Victron reaches the preset input amperage limit and then goes into power assist it abandons charging, i.e. it doesn't have the ability to sense an increased load on the mains circuit and then adjust the charge rate, it will try to charge at whatever power has been preselected even if it overloads the generator.

 

Power Assist is turned off onm Victrons advice. There is a Boost setting as well set to 2.