Blowing inverters when run off generator - EASUN iSolar SMR II Inverter 5.5KW ( REVO-WM II 5.5KW )

[ArranP]

EASUN iSolar SMR II Inverter 5.5KW ( SOROTEC / REVO-WM II 5.5KW )

I keep blowing up inverters when connecting them to a generator....

I am off-grid... when the inverters are running off batteries and solar panels they are fine, but after 3 or 4 days of rain the batteries are empty. So I connect the generator to the AC in on the inverter, it runs for 30 minutes or so charing up the batteries and some of then the inverter blows ( ICs in the inverters start blowing )... I have blown 3 inverters so far.... getting expensive.

Any knowledge on what might be happenign would be most welcome.

 

[Bud Martin]

Do you have info on the generator?
What is the exact model of the EASUN SCC/INVERTER?

 

[ArranP]

Do you have info on the generator?
What is the exact model of the EASUN SCC/INVERTER?

Generator : ZB-7500ES-T ( 230V 50HZ 6.0KW 6.5KW max )
http://www.zhanbua.com/product/view.php?id=462

Mitsu brand iron buffalo​

Model : ZB-7500ES-T Engine 190F​

engine type Air-cooled;4-strokOHV,single cylinder​

Ignition C.D.I​

start key / pull​

cc. 423cc.​

Horsepower 15 HP​

Voltage 220 V​

Frequency 50 Hz​

Maximum power 6.5 kw​

Current using 6.0 kw​

8 hours of continuous use​

Consumption rate 275g/kw.h​

96db sound​

4 wheels/handle​

25 liter oil tank​

1.1 liters of engine oil​

Weight 82 kg.​

Size 690x535x555 mm.​

Inverter : EASUN iSolar SMR II Inverter 5.5KW ( SOROTEC / REVO WM II 5.5KW )
https://www.easunpower.com/products/Bluetooth-5500W-Solar-Wechselrichter-500V-PV-230Vac-48V-100A-MPPT-Ladegerät

 

[Bud Martin]

The spec of the generator does not provide full details spec, such as.
I

Generator Set Specifications​

Basic generator specifications to include:

• Inverter type?
• Governor regulation class - The governor regulates engine speed (ISO8528 Part 1 Class G3) standard?
• Voltage regulator - Allows voltage to be constant (xx.x%) from no load to full load situations.
• Random voltage variations - Fluctuations in magnitude of supply voltage, (xx.x%) normal operation.
• Random frequency variations - The amount of frequency change (xx.xx%) during normal operation.

Does the ESUN manual show anything regrading to acceptable AC input requirement? My MPP Solar suggests me to use with inverter type generator.

Did you contact ESUN and ask them question?

 

[RCinFLA]

I'd have to place the blame mostly on inverter. A well designed inverter would shed the generator connection if gen had issues with output.

That generator looks like a synchronous generator that runs at 3000 rpm for 50Hz output. The engine rpm govenor must be stable and hold the engine speed very constant to avoid phase/frequency variations that the inverter cannot track and stay locked to. Do not take the inverter input frequency range as meaning it can vary that much during connection., The variation in rpm must be tight with no more then about 0.3Hz per second maximum variation due to wobbling generator engine rpm..

For a high frequency inverter it is better to use an inverter-generator that has tighter electronic control of its output frequency and waveform.

 

[JHovel]

I've had the same issue with my generator. I decided to put in a change-over switch instead of blowing the inverter again.
So when I need to use the generator, I flick the switch first. That disconnects the entire PV/Grid/Inverter input and connects the generator input socket. Then I start the generator and all is well....

 

[ArranP]

The spec of the generator does not provide full details spec, such as.
I

Generator Set Specifications​

Basic generator specifications to include:

• Inverter type?
• Governor regulation class - The governor regulates engine speed (ISO8528 Part 1 Class G3) standard?
• Voltage regulator - Allows voltage to be constant (xx.x%) from no load to full load situations.
• Random voltage variations - Fluctuations in magnitude of supply voltage, (xx.x%) normal operation.
• Random frequency variations - The amount of frequency change (xx.xx%) during normal operation.

Does the ESUN manual show anything regrading to acceptable AC input requirement? My MPP Solar suggests me to use with inverter type generator.

Did you contact ESUN and ask them question?

Yes, awaiting reply...

 

[ArranP]

I'd have to place the blame mostly on inverter. A well designed inverter would shed the generator connection if gen had issues with output.

That generator looks like a synchronous generator that runs at 3000 rpm for 50Hz output. The engine rpm govenor must be stable and hold the engine speed very constant to avoid phase/frequency variations that the inverter cannot track and stay locked to. Do not take the inverter input frequency range as meaning it can vary that much during connection., The variation in rpm must be tight with no more then about 0.3Hz per second maximum variation due to wobbling generator engine rpm..

For a high frequency inverter it is better to use an inverter-generator that has tighter electronic control of its output frequency and waveform.

maybe then the problem is two-fold

1. The inverter does not cope with an unstable generator supply.​

2. The generator is not an inverter-generator.​

 

[ArranP]

I've had the same issue with my generator. I decided to put in a change-over switch instead of blowing the inverter again.
So when I need to use the generator, I flick the switch first. That disconnects the entire PV/Grid/Inverter input and connects the generator input socket. Then I start the generator and all is well....

1st inverter blew - PV / Battery / AC-Ouput ( inverters working in parallel mode ) / AC-In Generator connected
2nd inverter blew - Battery/AC-Output ( inverters working in parallel mode ) / AC-In Generator connected
3rd inverter blew - Battery / AC-In Generator connected

So now I know that with just only the battery and AC-In connected to the generator, it must be the generator or the inverter or both that is at fault. Furthermore the generator is the only means I have of re-charging the batteries when there is no sun but I am hesitant to connect the gernerator again fear of what is my last inverter blowing...

$650 USD each, an expensive learning process....

 

[MurphyGuy]

The inverter can't handle the dirty generator...

 

[Hedges]

Could you have generator power a battery charger, so inverter never sees AC from generator?
From what I hear, usually best to use a charger no larger than about half generator wattage.

 

[740GLE]

Or is there a setting in the inverter charger to adjust the max Gen charging current to a lower value?

When the previous inverters “blew” what was the generator output voltage under load?

Are there any internal fuses of the inverter charger? Maybe voltage dropped so low current spiked causing the fuses to open?

 

[ArranP]

Or is there a setting in the inverter charger to adjust the max Gen charging current to a lower value?

I set the AC charge current to 80A, the generator is 6KW ( 6000 /48 = 125 ) so I thought well within tolerance, but in hindsight this maybe the reason as to why it blew the inverter.

When the previous inverters “blew” did the generator load up for a short time then blow or was it instant?

Attempts #1 and #2 it ran 1 to 5 mins, attempt #3 it ran for 40 minutes

Have you checked the output voltage of the generator with a meter to verify it matches what the inverter charger needs?

It fluctuates wildly from 200V to 260V depending on the draw from the inverters...

 

[Smokin]

Sounds like a PFC failure. Power Factor Correction Circuit meltdown. Should be easy to trace on the board. You should have the boards checked and find the point of failure and go from there.

 

[ArranP]

Sounds like a PFC failure. Power Factor Correction Circuit meltdown. Should be easy to trace on the board. You should have the boards checked and find the point of failure and go from there.

yes, I can see the MOS's that have blown, and already have purchased replacements, also I have purchased a desoldering sucktion gun but still I cannot desolder the MOS's... the gun sucks up the solder from the join but the MOSs still won't budge.

 

[Steve_S]

Caught it....
1) Install an AC Breaker between the Inverter's Genset INPUT and the Generator ! This breaker must be sized for the Max Output of the Generator Line being used. 6000W ÷ 220V = 27A (without correction) so 25A breaker.
2) Always start the Genset First, allow to run & reach output cycle (typically <60 seconds) then Allow output/charging.
!!! NEVER CONNECT to Inverter & Start Genset Cold with Power Output ON ! 90% Chance of Dirty Surge and POOFDAH ! FACT FOLKS !

Never Ever trust a breaker that is supplied on ANY Generator ! Even Generac uses quite crappy ones ! Mind you Generac has become crappy in the past 5 years since the "Investment Company bought it). A High Quality AC Breaker is the only thing you can genuinely trust.

A quick check and that Generator is NOT Compatible with a Generator Control Start Module. An Inverter/AIO that has an AGS (Auto Gen Start) Port (most do) will connect to a GSCM which starts & stops a genset, more advanced ones monitor genset output too.

NOTE On Inverter/Chargers...
When Batteries are being charged from an AC Source, the AC power is also being "Passed Through" the system to service loads during the process. If using a Pue Sine Inverter Generator then that is what passes through BUT if using a Mod Sine Generator, then Mod Sine is what is passed through. Inverter/Chargers DO NOT convert Sine Waves. This Can & Will affect all AC Devices in use and many "more sensitive" devices will not like that.

Hope it helps, Good Luck

 

[ArranP]

Caught it....
1) Install an AC Breaker between the Inverter's Genset INPUT and the Generator ! This breaker must be sized for the Max Output of the Generator Line being used. 6000W ÷ 220V = 27A (without correction) so 25A breaker.
2) Always start the Genset First, allow to run & reach output cycle (typically <60 seconds) then Allow output/charging.
!!! NEVER CONNECT to Inverter & Start Genset Cold with Power Output ON ! 90% Chance of Dirty Surge and POOFDAH ! FACT FOLKS !

Never Ever trust a breaker that is supplied on ANY Generator ! Even Generac uses quite crappy ones ! Mind you Generac has become crappy in the past 5 years since the "Investment Company bought it). A High Quality AC Breaker is the only thing you can genuinely trust.

A quick check and that Generator is NOT Compatible with a Generator Control Start Module. An Inverter/AIO that has an AGS (Auto Gen Start) Port (most do) will connect to a GSCM which starts & stops a genset, more advanced ones monitor genset output too.

NOTE On Inverter/Chargers...
When Batteries are being charged from an AC Source, the AC power is also being "Passed Through" the system to service loads during the process. If using a Pue Sine Inverter Generator then that is what passes through BUT if using a Mod Sine Generator, then Mod Sine is what is passed through. Inverter/Chargers DO NOT convert Sine Waves. This Can & Will affect all AC Devices in use and many "more sensitive" devices will not like that.

Hope it helps, Good Luck

Is a single 25A AC Breaker all that is needed to protect an inverter from a dirty generator ? I assume it will take care of an amp surge, but what about a voltage surge ? I would welcome more comments relating to how to protect the inverter from a dirty generator... Thank you.

 

[Steve_S]

Al;pl breakers will take a % of Voltage/Amperage above their rating for a few milliseconds, which is what they are supposed to do. The breaker is to protect both ends, it does not fix problems.

There is very little you can do to "filter & condition" genset power (affordably anyways) and that can be a bugger.
My own Genset that I use for backup is a 7200/9000W Construction Grade (I also use it for my Mig Welder & Big Compressor) and it's not that "clean". I'm in Canada so we use 120VAC Single Phase & 240 Plit Phase @ 60Hz. My Genset will float from 56 to 63hz and the voltage (120) can range from 115 to 122 VAC. Fortunately because I use a Samlex EVO Series Inverter/Charger (tier-1 NOT cheap product) I've programmed thresholds to handle it. MOST Inverter / Chargers & AIO's are less tolerant until you get the higher end, more programmable models.

 

[apo]

yes, I can see the MOS's that have blown, and already have purchased replacements, also I have purchased a desoldering sucktion gun but still I cannot desolder the MOS's... the gun sucks up the solder from the join but the MOSs still won't budge.

I've learnt a lot from this very good magician https://www.youtube.com/c/ALayoubiMaintenanceCenter . He is adding firstly tin (to have better contact with gun head).

 

[ragman]

EASUN iSolar SMR II Inverter 5.5KW ( SOROTEC / REVO-WM II 5.5KW )

I keep blowing up inverters when connecting them to a generator....

I am off-grid... when the inverters are running off batteries and solar panels they are fine, but after 3 or 4 days of rain the batteries are empty. So I connect the generator to the AC in on the inverter, it runs for 30 minutes or so charing up the batteries and some of then the inverter blows ( ICs in the inverters start blowing )... I have blown 3 inverters so far.... getting expensive.

Any knowledge on what might be happenign would be most welcome.

EASUN iSolar SMR II Inverter 5.5KW ( SOROTEC / REVO-WM II 5.5KW )

I keep blowing up inverters when connecting them to a generator....

I am off-grid... when the inverters are running off batteries and solar panels they are fine, but after 3 or 4 days of rain the batteries are empty. So I connect the generator to the AC in on the inverter, it runs for 30 minutes or so charing up the batteries and some of then the inverter blows ( ICs in the inverters start blowing )... I have blown 3 inverters so far.... getting expensive.

Any knowledge on what might be happenign would be most welcome.

Evrything I have found out about running gen set into inverter says bad idea but use a battery charger for your bank run off gen set is the way to go