1 hour ago, Chris Hobson said:

After months of putting it off this morning I finally wired up the changeover switch so that I could run the Axpert off a cheap Chinese gennie. It works! There is a slight hum on the inverter which I don't like. The frequency is all over the place.

Awesome, thanks Chris. I will have to try the firmware upgrade then. I get your point TTT, the genny in question, however, is a fairly decent low noise diesel one which is definitely better (i guess and hope) than the ones you guys are describing which i also have experience with. It's frequency reading where fine and steady on the Axpert previously, even though the internal changeover still didn't want to happen...

Is the best way to have a genny autostart using a Victron battery monitor as peter has (guessing the dry contact signal provides what is needed at the set voltage?) What other options are there?

Jip the market was flooded with cheap generators at the building material stores. None knew of voltage regulation or what happens with a small flywheel.

Auto starting a gennie using a Victron BMV's relay, that's what I would have done. SOC reached say 50%, start gennie. SOC 90% switch off gennie, or some such.

With auto kill switch if fuel is low or gennie overheats.

42 minutes ago, The Terrible Triplett said:

Auto starting a gennie using a Victron BMV's relay, that's what I would have done. SOC reached say 50%, start gennie. SOC 90% switch off gennie, or some such.

So you generate electricity at >>R10/kwh and store it in a medium that's 70% round-trip efficient :-) Much as that's a terrible picture, I suspect the long and short of it is that when you're out in the bundus on your own, this is often better than the alternative.

1 hour ago, plonkster said:

So you generate electricity at >>R10/kwh and store it in a medium that's 70% round-trip efficient :-) Much as that's a terrible picture, I suspect the long and short of it is that when you're out in the bundus on your own, this is often better than the alternative.

You are correct...but to get off-grid and avoid the nasty R1500pm Eskom 'line-fee' in a rural (bundu) setting it is sometimes worth it.. Mostly (ideally) it is only needed the one or two times per month that very cloudy weather is around and batts are not properly recharged by solar the day before

Plaasjaap, you do  know that you don't have to charge the batts full every day? You can have a running total type over 7 days or so.

Long as you don't go below 50% DOD every day, if is ok once a week or so, depending on batteries you have.

Off grid does not have the same "rules" we have in cities i.e. Eskom cheaper than batts. Off grid batts are cheaper than generator.

19 minutes ago, plaasjaap said:

You are correct...but to get off-grid and avoid the nasty R1500pm Eskom 'line-fee' in a rural (bundu) setting it is sometimes worth it.. Mostly (ideally) it is only needed the one or two times per month that very cloudy weather is around and batts are not properly recharged by solar the day before

Well yeah, that is precisely what we did in the 80s. Except, we didn't charge using an inverter/charger or separate charger. The Hoffberg included a DC generator for charging.

I have one of those. It gives out about 54V on the DC side, but I rather run the 220V into my inverter to do the battery charging. Maybe you can offer some insight as to why the cranking circuit on the hoffberg is 36V, but the output is 48V? That's the main reason why I hand crank start my genny as pulling 36V from part of my battery bank upsets the balance of the whole bank. So I could get 3 normal car batteries to crank the hoffberg, but then how do I charge them as everything else is for charging 48V? Pass the crank handle please.... 

1 minute ago, DeepBass9 said:

Maybe you can offer some insight as to why the cranking circuit on the hoffberg is 36V, but the output is 48?

This is a throw back to when everyone's  lights on farms were 32V DC. 

1 minute ago, DeepBass9 said:

Maybe you can offer some insight as to why the cranking circuit on the hoffberg is 36V, but the output is 48?

Because it's designed to charge a 36V bank. For some reason that was the de-facto standard (along with 32V incandescent lamps) on farms. But you have to charge a battery at 2.45V per cell, so you need to charge at 46V or so. The "36V" generator on the Hoffberg doesn't make enough to charge a 48V bank, because it needs to go up to 60V to do that.

You could use a boost converter... that'd work. I doubt it'd be more efficient that what you're doing now though :-)

8 minutes ago, DeepBass9 said:

That's the main reason why I hand crank start my genny

I used to do that simply as a matter of pride. And because a Hätz starts easy, no excuses.

OK, makes sense. So nothing really useful to be done with it, unless I want to splash out on 3 batteries and another charger for 36V. At least the cranking warms you up a bit . Not so much since the engine overhaul as now it starts very easily, even on very cold days.

I suppose the 32V was to make up for the voltage drop along the cable to the outhouse?

The reasoning behind 36V is probably that that was the closest you could do to 32V using regular 12V batteries. The reason for 32V apparently goes back to the 1930s and even earlier, the world- and vietnam wars. 32V was low enough to be safe in almost all circumstances. Some googling also hints to the bus lamps used in the USA (which were really 28V), and then of course after every war you could pick up those generators dirt cheap. This would include our own bush war, which yielded many Hoffberg and Anderson Alternator/Generator combos. That's probably why they were popular: because that's what the army used.

Also... this.

http://www.smokstak.com/forum/showthread.php?t=105233

Interesting

4 hours ago, The Terrible Triplett said:

Plaasjaap, you do  know that you don't have to charge the batts full every day? You can have a running total type over 7 days or so.

Long as you don't go below 50% DOD every day, if is ok once a week or so, depending on batteries you have.

Off grid does not have the same "rules" we have in cities i.e. Eskom cheaper than batts. Off grid batts are cheaper than generator.

Hi TTT. Yes, thanks i get that - the original investment in batts at my friend's should have been bigger, but his main problem is they can't seem to get their nightly use down which is the most important thing as we all know. They should have it down to 3 or 4 kwh during night time hours, but they can't seem to get below something crazy like 12kwh. He has 21.6 kwh total stored - so it's over 50%...So he needs to boost batteries a few hours at night unfortunately - now he is using eskom and paying line fees even though he already had the generator and had the goal of being offgrid...

12 hours ago, plaasjaap said:

his main problem is they can't seem to get their nightly use down

Send him to me. Serious, have had cases and once we work though it the people get really upset why they where never told.

Flip side ... as hulle nie wil leer nie ... dan maak ons baie geld tot hulle leer. 

12 hours ago, plaasjaap said:

but they can't seem to get below something crazy like 12kwh.

That's crazy as you said. We use an average of 11kWh a day and perhaps 3kWh overnight. I am not trying to be frugal and have just cobbled a power-hungry computer with an old 20" CRT screen for my boy.

Many thanks to all of you.  

I asked the local installer to do the upgrade -- but he was not able to do that.  He also claims that upgrading would not solve the problem.  And i myself have no windows computer (Mac user). I'm still stuck with that problem. 

12 minutes ago, PeterGutti said:

Many thanks to all of you.  

I asked the local installer to do the upgrade -- but he was not able to do that.  He also claims that upgrading would not solve the problem.  And i myself have no windows computer (Mac user). I'm still stuck with that problem. 

Other people have done the upgrade and reported that their generators did indeed work on the inverter. Him not being able to do the upgrade doesn't mean it won't work. 

23 hours ago, PeterGutti said:

Many thanks to all of you.  

I asked the local installer to do the upgrade -- but he was not able to do that.  He also claims that upgrading would not solve the problem.  And i myself have no windows computer (Mac user). I'm still stuck with that problem. 

 

After having a look at your photo an reading your pdf I noticed that you had setting 1 on SBU, meaning that the inverter will take power from SOLAR, BATTERY then UTILITY, in that order.

If you set it to UTI it will accept utility power as priority and only use battery and solar when utility is not available.

This would explain why the inverter is seeing the AC but not accepting it, it's running from solar.

When the solar is disconnected or not generating (at night) the inverter will accept UTILITY to charge batteries and supply the load.

Try changing setting 1 to UTI and see if it helps

•  

On 18/8/2016 at 9:57 PM, Noobie said:

 

After having a look at your photo an reading your pdf I noticed that you had setting 1 on SBU, meaning that the inverter will take power from SOLAR, BATTERY then UTILITY, in that order.

If you set it to UTI it will accept utility power as priority and only use battery and solar when utility is not available.

This would explain why the inverter is seeing the AC but not accepting it, it's running from solar.

When the solar is disconnected or not generating (at night) the inverter will accept UTILITY to charge batteries and supply the load.

Try changing setting 1 to UTI and see if it helps

•  
•  

Noobie Hello! Thank you for the tip.  Will try soon.

7 hours ago, PeterGutti said:

Noobie Hello! Thank you for the tip.  Will try soon.

Let me know if this solves the issue

On 18/8/2016 at 9:57 PM, Noobie said:

 

After having a look at your photo an reading your pdf I noticed that you had setting 1 on SBU, meaning that the inverter will take power from SOLAR, BATTERY then UTILITY, in that order.

If you set it to UTI it will accept utility power as priority and only use battery and solar when utility is not available.

This would explain why the inverter is seeing the AC but not accepting it, it's running from solar.

When the solar is disconnected or not generating (at night) the inverter will accept UTILITY to charge batteries and supply the load.

Try changing setting 1 to UTI and see if it helps

•  
•  

Setting 1 means "Output source priority" or load power source. I can test that.  I think setting 16 "Charger source" is controlling the power source for battery charging. I changed that to CUT (Utility first) without success.

Last night i did a test with all pv modules disconnect (night).  The utility (power gen) gets connected and after a few seconds disconnects. When connected the status chages from bypass to battery load. Its a loop of status'.

So, at the moment only the sun can charge my batteries, which is bad news, because we expect bad wheather for days!

On 1/8/2016 at 0:06 PM, plaasjaap said:

Awesome, thanks Chris. I will have to try the firmware upgrade then. I get your point TTT, the genny in question, however, is a fairly decent low noise diesel one which is definitely better (i guess and hope) than the ones you guys are describing which i also have experience with. It's frequency reading where fine and steady on the Axpert previously, even though the internal changeover still didn't want to happen...

Is the best way to have a genny autostart using a Victron battery monitor as peter has (guessing the dry contact signal provides what is needed at the set voltage?) What other options are there?

Chris, do you have two inverters in parallel mode?  As i have? And.. what software tool can update the firmware?