Inverter does not recognize generator power

dougahole · November 2020

I recently purchased a 4000 w 24 volt split phase inverter from Sungold Power. This inverter is identical to my AIMS 3000w inverter which I have no issues. I have a split solar array using two FlexMax 60 controllers and with two strings in series. Batteries, 12 Kyosonic Gel 450 ah (3 strings, 4 x 6 v in series for 24 volt)

The inverter is wired to the electrical panel as well as directly to the Honda 7000 inverter/generator.

For whatever reason, the inverter does not recognize the generator power. Can anyone shed any light on why this condition could exist. I have everything grounded properly but suspect that may be part of the problem but do not know how to resolve it.

BB. · November 2020

Have you measured the generator L1/N/L2 voltages? Have you measured the frequency... The inverter generators are usually dead on accurate... But the inverter control modules have been known to fail (not always zero output, but wrong voltage/frequency).

I guess this the inverter?

https://sungoldpower.com/products/4000w-peak-12000w-dc-24v-split-pure-sine-wave-inverter-with-charger

Use a volt meter to make sure that the AC2 (generator/backup power input) is powered correctly (no mixed up L1/N/L2 connections)?

There is a SW2 setup: 140V-270VAC/184V-253VAC (select by SW2)

Looks like this unit needs 240 VAC (L1/L2) specifically--Cannot use 120 VAC input.

-Bill

MichaelK · November 2020

When you say it's not recognized, do you mean the inverter doesn't know the generator is there, or refuses to accept the power the generator is producing. IE: does the inverter load up the generator, then drop it, or completely oblivious?

In my case, my Schneider inverter would link to my generator, load it for a second or two, then drop it. What I found was that the default input amperage for the charger function was 140A, which was far in excess of what my generator could output. The inverter is looking at the QUALITY of the power being produced and was deciding it was not clean enough. When I reconfigured the generator input to 10% (14A) the inverter would link to it and accept the generator's power.

I would then incrementally increase the percentage a point or 2 up to about 37% (52A). Above that the inverter would again drop the generator's input. So, at above ~2600W the generator could not produce current clean enough to satisfy the inverter.

dougahole · November 2020

Thanks for your response. The charger/inverter, Honda 7000, is not recognized. Typically, once the generator is booted up, the inverter recognizes the power and displays an amber LED indicating acceptance of the external power source. This inverter has a setting that the user can adjust the output current (0-100%). I do not know at this time if that setting may have been changed inadvertently as the installation is at the cottage and I am not there. I will check that out this weekend. Do you see this having an effect of rejecting the power?

mike95490 · November 2020

For the inverter to qualify the generator, it must
1) be within the voltage range the inverter is looking for
2) be within the frequency range (generally 3600RPM = 60Hz)
3) be stable enough that the inverter qualifies it. If you hear the generator surging or hunting, that's not good

mcgivor · November 2020

How about neutral ground bonding? The Honda will most likely have a internal neutral bond, there should be only a single bonding point , if there are multiple points it could cause problems with qualification of the generator. Some inverter chargers will lift the neutral bond when transferred to auxillary AC source, others may not, consult the manual.

dougahole · November 2020

Thanks for the info on the 'neutral ground bonding'. I will check the manual to see how to approach the wiring issue. If you know anything specific I would appreciate it.

RCinFLA · November 2020

Grid interactive hybrid inverter-chargers match the AC freq, phase, and voltage before connecting to AC source,.

Models that do not have two separate AC input option, grid and gen, often set their default allowable frequency lock range to grid specs of a couple of tenths of Hz around grid freq.

Inverter-generator are usually pretty good for freq but may not be within grid spec freq range,.

See if your inverter-charger has a AC input freq range setting and widen it out a bit.

Another thing that is often an issue is stability of generaor freq. Again inverter-gens rarely have an issue with this. The inverter-charger will not tolerate a warbling AC line frequency. Their lock tracking bandwidth is much tigher then their freq allowance spread.

You did not mention any details of what you are seeing. Does an LED indicate presence of input voltage? Does it initially connect then quickly drop the generator?

Leave ECO mode off on inverter-generator. With ECO mode, sudden loads cause inverter-generators to dip in output voltage for a short period while engine speeds up which can cause inverter-charger to release from inverter-generator.

If inverter-charger has 50Hz - 60Hz option make sure it is set to your grid/gen freq.

Honda 7000 inverter-generator has two 120vac inverters operating with outputs of inverted phasing so neutral should be used with 240vac output.. 120vac loads on inverter-charger will create neutral current pass thru to generator.

Basspig · December 2021

I wish I had stumbled into this thread before I bought my Sungold Power 6000W inverter. It won't pass the generator power through. It remains on battery. My generator is fine with all of my APC UPSes, so I never even gave it a thought that this Sungold unit would have a problem with generator power, especially since the manual shows a generator hookup to charge the batteries.
I'm getting a "AC ABNORMAL 238V" reading on the status panel when the genny is running. I've tried both positions of SW2 and neither lets the generator power qualify.
I have a Northstar brushless generator, which replaced the Generac which was giving my UPSes trouble. I get very stable output from the 10kW Northstar genny.
This is really bad news, as this thing is heavy to ship back and will cost a ton of money in freight.

BB. · December 2021

When you change SW2 setting, did you power down the inverter for a minute (ac and dc) to force a cold start/reboot to read the new switch settings?

238vac for 240 vac input should be fine. Sounds like expecting 120vac.

You have an ac neutral from genset to inverter and correctly wired? L1-N and L2-N is 120vac and L1-L2 is 240vac on inverter AC input?

There are other voltage and frequency settings that could be incorrect for inverter...

100 vac 50 or 60 Hz Japan

120 vac 60 Hz USA

208 vac 60 Hz USA (1 phase of 3 phase)

230 vac 50 Hz Europe

240 vac 60 Hz USA

Make sure inverter is correctly configured.

Bill

Basspig · December 2021

Yes, I powered off the inverter before changing any switch settings and then powered up, watched it go through initialization and then online.

The labeling of the line side (shore power) of this inverter is a bit confusing because instead of Neut-H1-H2, it has GND-H1-H2 on the input side. Only the output side is labeled NEUT=H1-H2 and those go to the main panel.

The inverter output is 242 VAC across H1-H2 terminals and half that from either to Neut terminal and 59.88 Hz frequency as measured on my Fluke 867B. It appears correct for northeast US.

I even played with the generator speed control, lowering it slightly until I measured 60.0Hz with a +/= 0.1Hz variation. The inverter still did not like the generator power and refused to charge the batteries nor switch over to generator pass through mode. I followed the diagram as it is shown in the manual. The manual does warn NOT to tie input neutral to output neutral.

Image: https://us.v-cdn.net/6024911/uploads/editor/5s/5td1aajcfajs.jpg

Dave Angelini · December 2021

It is a problem when you buy equipment not sold in the store here at Wind and Sun. There just is very little support, and for offgrid that is the kiss of death. When I looked up this inverter on Google the search said.

SunGoldPower was founded by a famous engineer in 2010, with rich experience and skilled technology. We are focused on providing the highest quality green power products for the world. Our main products cover solar inverter, low frequency inverter, inverter welder, solar panel and other green energy products.

I would try your test again with small heater running as a load directly on the genset if you have not already.

BB. · December 2021

Update: Basspig supplied a link to the manual. And this unit is pure 240 VAC input--No Neutral is connected from the genset/AC mains to the inverter AC input--Just L1+L2+Green wire safety ground--Neutral is unconnected/unused. -BB. 12/18/2021

Yes, for operational purposes, neutral is, more or less also ground, in north America.

Code point of view, there needs to be a safety/green wire ground too for electrical safety.

You could have other issues if, for example, the AC input ground is also connected to metal chassis ground (the "input ground" should be floating and not connected to metal chassis).

If the "input ground" is connected to sheet metal, then you could trip the generator GFI protection. And we would need to talk more about this (if issue).

Bill

Basspig · December 2021

Currently, I have the ground terminal on the chassis of the inverter connected to safety ground. That is connected to earth ground and the panel ground. Including the 4th wire (safety ground) from the generator shed. I've tried different iterations of this, with some grounds floating and others connected, but no effect on the problem.
It's baffling because I measure the correct voltages at the input terminals. I'm unable to figure out why this isn't working. I may have to experiment by hooking mains utility power to the input terminals and see if that works. If I still get the abnormal AC readout, then I know something's wrong with the inverter.
The input ground is connected to the GND terminal at the input line connections as shown in the diagram from the users manual that I posted. I don't know if internally to the inverter that ground may be tied to chassis or not.

BB. · December 2021

I don't think the chassis green wire neutral is this problem. As long as the voltage at terminals is correct.

It sounds like configured for 120 vac. And you are getting the 238 vac alarm for a perfectly valid voltage (unless you are getting Lx to neutral/ground connection voltage of 238 vac there).

Bill

Basspig · December 2021

To rule out a generator problem, I connected the mains breaker to the input of the inverter. I'm getting the exact same error. The neutral wire (also building ground) is tied to the GND terminal on the inverter's input wiring terminal block. One hot wire is connected to HOT1 and the other hot wire is connected to HOT2. The inverter status panel shows 242VAC and AC ABNORMAL again. I have 121V from either HOT to GND terminal on the input. It is wired according to the diagram in the manual.

This is a split phase inverter with a 240 VAC in/out, so I'm quite certain it's configured for the right voltage. If it was looking for 120V Hot to Hot, that would mean each leg was only 60VAC, not a valid voltage for the US.

This is the product I bought. It says 240V input and 120/240 output, split phase.
https://sungoldpower.com/collections/120v-240v-split-phase-inverter-chargers/products/6000w-peak-18000w-dc-48v-split-pure-sine-wave-inverter-with-charger?variant=39652614996105

BB. · December 2021

OK, if this is a 240 VAC input inverter, there are only L1 and L2 (240 VAC) connections to your genset/AC mains. There is no neutral connection (page 17 from your manual, split phase connection diagram Wiring Option 2--Neutral from 120/240 VAC split phase power source is unconnected. Just L1+L2+Green Wire safety Ground to AC input of inverter).

The "ground" connection symbol on the AC input is just green wire safety ground.

And I see nothing you can do with a 240 VAC rated inverter that would give you a 238 VAC input voltage alarm for your unit.

On page 24/25, the max AC input is a bit confusing... Either 243 VAC or 253 VAC... For a US 240 VAC system, should be 264 VAC max input/trip.

Input Voltage Range
Narrow: 100~135VAC / 194~243VAC;
Wide: 90~135VAC / 164~243VAC;

Input Frequency Range
Narrow: 47-55±0.3Hz for 50Hz, 57-65±0.3Hz for 60Hz
Wide:43±0.3Hz plus for 50Hz/60Hz

And from the website page:

*AC input Range (Grid or Generator): 140V-270VAC/184V-253VAC (select by SW2)

vs 253 volt high voltage trip and 243 VAC re-engage in the specs...

If 243 trip (I believe the inverter switch to battery power if "trip"), that is too low. My AC utility power probably runs closer to 245 VAC. You could be getting a surge >253 VAC when connecting genset input. (note the 120 VAC is 135 VAC input range which is 270 VAC max input for a split phase 240 VAC input--253 VAC is too low, and 243 to re-engage is also pretty low).

-Bill

Basspig · December 2021

So we concur that I have the correct unit for my electric power, but there is a question about whether the genset neutral wire should be hooked to the ground terminal at all. Hmmm.. But remember that I also tested with mains power this morning and have the same problem, which makes me suspect that may be I have a defective unit.
I just tried disconnecting the generator neutral from the ground terminal and just float the hot terminals and started the generator and then the inverter, however, I am still getting the same error.

BB. · December 2021

How is your generator connected to your place?

Genset to extension cord to inverter?

Genset to "main panel" to multiple circuit breakers? (Main panels generatlly default to tying Neutral bus bar to ground bus bar)

Normally, for later genset {3,500 Watts or larger generally), the genset may already have neutral to chassis ground bond in the genset. However, always check the manual.

For the Honda eu7000i (check s/n of genset and manual range)--The Neutral is "floating" with respect to safety ground:
https://cdn.powerequipment.honda.com/pe/pdf/manuals/00X31Z376210.pdf

Image: https://us.v-cdn.net/6024911/uploads/editor/9g/pp3al165o2wc.png

For 99% of appliances, floating or grounded neutral does not matter (some fluorescent tube fixtures may need earth ground neutral and fixture sheet metal grounded for starting. Some spark ignition stoves/heaters need ground bonded neutral).

The other reason for neutral/ground bonding... If you have a short between L1 (or L2) to ground (electric box, sink, water pipe, etc.)---A "floating" 240 (or 120/240 VAC) will not trip a breaker (no return path for current). It is possible to "electrify" your (for example) kitchen sink and electrocute somebody.

If you have bond Neutral+Ground together, then any short from Lx to grounded metal/piping will trip the breaker.

Normally, you do not want two or more N+G bonding in your home/cabin/RV (say in the genset, or in the inverter, or in the "main breaker panel"). You only want N+G in one location. For RVs (and boats, etc.) that may run from inverter/genset/shore power--N+G bonding generally needs to be "switched" depending on power source.

Review the N+G setup for your AC inverter--Its AC output may be floating or bonded. The manual has a warning about N+G bonding with AC input to output (I have not read the details at this time).

-Bill

BB. · December 2021

Yea... I don't think the N+G bonding (or floating) is your issue here...

-Bill

Basspig · December 2021

Up until I bought this inverter, I had the genset hard wired into the main panel via a dual 40A breaker. The gen neutral wire went to the neutral/ground buss bar in the panel and the H1 and H2 wired each went to a pole on the breaker. When utility power is out, the main breaker is shut off and the generator breaker is switched on so the generator can feed the house.

Generator is a Northstar 13000 model. Honda GX690 engine (2 cyl). I have the 50 amp 240V outlet of the generator mated with a 50 amp plug which goes to the main breaker panel as described above. I'm taking the neutral and hot lines to the panel and the safety ground to the ground buss.

Now for the hookup to the inverter, I moved the generator hookup from the panel to the input of the inverter. Neutral, H1 and H2. The inverter is seeing a voltage that is within the manual's stated acceptable range.

I must emphasize that in order to rule out this being a generator issue, I also tried feeding it with 240V AC from the panel. I simply moved the "output" connection that I had going to the breaker to feed the panel, to the "input" side of the inverter. Mains power should qualify, as it's stable and in the correct voltage range. In this case, the GND was connected to the panel GND/NEUT buss and the H1 and H2 were connected to their respective poles on the breaker. The fact that it doesn't qualify shore power really raises doubts that the inverter's method of qualifying power quality is efficacious.

RCinFLA · December 2021

It appears from manual that the input only uses 230-240vac and the transformer within the unit is center tapped to provides the neutral for output.

The neutral ( L1-N and L2-N ) from generator (or grid) and neutral from inverter transformer may not precisely match for each 120vac voltage phase leg. Leave the generator neutral (wht) disconnected and only input the Blk and Red 240vac input wires to inverter.

You can connect generator case ground to inverter ground. Make sure the generator is not neutral bonded to its chassis case.

Since there is color printing in the manual it is sort of stupid for the wiring diagram in manual to have all the AC wires in the drawing black in color.

Image: https://us.v-cdn.net/6024911/uploads/editor/4c/w4h8pjdpmnxz.png

Image: https://us.v-cdn.net/6024911/uploads/editor/4y/anwko96dh0ce.png

Basspig · December 2021

As a test, I tried connecting the mains power without the neutral, just hot 1 and hot 2 up to the input side of the inverter. The display reads 242 vac and "AC ABNORMAL" so I think there's something mis configured or broken inside the inverter itself.

BTW, I can't find these drawings inside the manual I have. Which manual did you download?

Basspig · December 2021

It's been nearly a week now, and my three e-mails to Sungold Power have gone unanswered as well as my contact requests through their web form and I'm growing concerned that I may have to file a complaint through Paypal. This whole thing is being financed through Paypal Credit.
I've currently no way to charge the battery bank and we had a power outage this morning and the generator would not pass through, so we ran on inverter. Battery voltage is down around 48V now.
I was thinking that when I build a solar array, I can change the batteries from the array, but that won't be likely til next spring.
In the meantime, if I have a defective unit, they ought to replace it.

BB. · December 2021

And you should probably find a charger for your genset to save your battery bank--now. Lead acid batteries, in general, do not like to sit around at less than 75% state of charge. If this goes on for days/weeks, it will ruin your battery bank.

I think you have done all you can. Time to file for your money back if you cannot get the issue addressed.

-Bill

Basspig · December 2021

The batteries are LifePo4, not lead acid, but I still need to come up with a charging solution.

BB. · December 2021

Yes, the LiFePO4 are happy.

No so much you.

Hope you can get a solution during the holidays.

Bill

RCinFLA · December 2021

For the inverter running on batteries, you might want to check the AC output voltage with a DVM for the 240vac and each 120vac leg. With no load the two 120vac output legs should match very closely. Compare your DVM readings to what the inverter reports for its output voltage.

Also check the freq output of AC from inverter when running on batteries. Specifically make sure it is not outputting 50 Hz.

Did you try changing position of S2 dip switch. I believe all it does is restrict or widen acceptance range of input AC voltage. If your input is in mid range it should not matter if it is in restricted input voltage or wide voltage range setting.

However if the inverter voltage, by itself, on batteries is high or low it may not connect when AC input is in mid range but far away from inverter running on batteries. This would indicate an inverter calibration problem where the controller thinks it is putting out correct inverter sourced AC voltage when it is in fact too high or too low. If the same calibration factor is applied to AC input it will think input is out of range.

Other issue that can happen is a stuck input connect relay. Relay must initially be open so the inverter can adjust it phasing to match generator before closing relay contacts. If this happens the inverter should immediately shut down as soon as external AC input is applied. I did not see you reporting this kind of issue.

Basspig · December 2021

The output of the inverter looks to be dead nuts on.. 242V across H to H and 121 on each leg. 59.98Hz according to my frequency counter.
I did play with SW2 and restart the inverter, but it did not solve the issue.
The input reads about 238V on generator and 242 on mains power. I've tried wiring each of these sources to the input alternately to see if may be it was a problem of generator being at 61Hz.
The inverter keeps going when I apply AC to the input. No relay activity. It just says "AC ABNORMAL" when the display scrolls to the input source status.
I'm pretty convinced this is not how the unity should operate. Something is wrong somewhere, but I don't know what without voiding the warranty.
For now, I've rigged up a 40V 100VA transformer and a full wave bridge rectifier to charge the batteries at about a 50Wh rate. The batteries are up to 51.6V now and I am continuing the charging during the day. It's a trickly charge, but it's working. If I can hook a bunch of solar panels to this, with 40 240W panels, it could theoretically keep the batteries topped off even when the inverter is in use.

Estragon · December 2021

In post #23 you note the display says "242vac AC ABNORMAL"

Mains Supplies of 220VAC, 230VAC and 240VAC. What voltage equipment should I use? (trminternational.com)
What are the differences between 220VAC, 230VAC and 240VAC Mains Supplies and what voltage equipment should I use? | Schneider Electric UK

That number appears to coincidentally (?) match pretty well with the maximum voltage of European 220v gear. I dunno, but coincidences like that make me go hmmm. Could be the wrong hardware, or maybe the wrong soft/firmware on the right hardware?

Basspig · December 2021

Is it possible the inverters they sell are only for China and Europe use? American power is 240V split phase for residential zones.

Inverter does not recognize generator power

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