# EU7000is no load voltage



## JRHill (Nov 19, 2020)

This is an off-grid blended system of the Honda with an Outback Power solar for charging the batteries during low light. The generator's operation is completely automated. The generator is 4 years old and just shy of 2k hours. Over the last week I have been having problems and noticed something odd this morning. During the programmed 5 minute warm up I was closely watching the system console (Outback Mate3s) and open circuit AC voltage from the generator was slowly roaming from 121vac down to 118 and up to 126. There is no sound change and the engine is running great.

This really unusual as the unit has always been a rock solid 124-126vac under load or not. Once the unit has warmed up and connected to the system the AC from the unit is rock solid at 121vac. Seems OK but until recently it has always been 4vac higher. The generator's Hz is right on at 60.

Any ideas about the voltage output?


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## pipe (Jun 27, 2021)

What is the condition of the mppt and batteries? Isolate or remove batteries (test) - ie. are each of the same age and residual voltage?


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## JRHill (Nov 19, 2020)

pipe said:


> What is the condition of the mppt and batteries? Isolate or remove batteries (test) - ie. are each of the same age and residual voltage?


The four batteries are SimpliPHI 3.8 and < than one year old. I didn't want to head off into OB programming and equipment - it would be a distraction. _This all about the open circuit (non-connected) output of the generator during warm up._ But to answer you, once connected, the system balances perfectly per programming. Solar has charging priority by .4vdc if available and the generator fills in which always runs the full 20aac. Total DC charge to the batteries is the default 80adc which I never hit esp in the winter (which is the only time the generator is needed anyway).

The other thread about pulling data from the EU7000is real time gets more interesting yet. BTW, there are no error codes on the Honda. Thanks for your input, really.


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## pipe (Jun 27, 2021)

Read this on the 3.5 FAQ page...



> each PHI 3.5 kWh 48V battery equates to a maximum charge and discharge rate of 33A continuous


pondering (not knowing...) if the observed initial V drop is an indication there is a high surge due to low battery capacity and the mppt attempting to rush things at warmup


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## JRHill (Nov 19, 2020)

pipe said:


> Read this on the 3.5 FAQ page...
> 
> pondering (not knowing...) if the observed initial V drop is an indication there is a high surge due to low battery capacity and the mppt attempting to rush things at warmup


Nope. You keep relating to solar feed: MPPT or loads while on solar. At this time of year we don't have solar feed or very little. Again, this is before the generator connects, warming up, with NO solar. This is an increasing/decreasing voltage at open circuit from the EU7000is. Even if connected the OB inverter is in pass through mode. Everything from generator to the inverter passes through to feed circuits and 20aac goes to charging batteries. Surge loads don't happen, at least on our system. Our well is on a completely different system and even if I plugged it in its slow ramp up to max 780watts (thank you Grundfos). I didn't want to get into solar stuff. This is not solar. This is an EU7000is issue.

So why the lower idle voltage on warm up and then the lower voltage at run time? BTW, no difference on Hi/low.

Gosh I don't want a service call at the shop. The closest full service shop would be a five hour round trip and Lord knows how long?


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## JRHill (Nov 19, 2020)

I brought this issue here first because its a generator problem. I am active on the Outback Forum but that is programming and configuration. Programming and configuration is in order. I am researching the change in open circuit voltage at the EU7000is. It's not a solar equipment issue since its all off line until the genset connects.


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## tabora (Sep 6, 2018)

JRHill said:


> open circuit AC voltage from the generator was slowly roaming from 121vac down to 118 and up to 126.


That's well within the 120V service spec of 105V to 132V. That would not concern me under a no-load condition, since you state that the loaded condition is right at 121V.


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## JRHill (Nov 19, 2020)

tabora said:


> That's well within the 120V service spec of 105V to 132V. That would not concern me under a no-load condition, since you state that the loaded condition is right at 121V.


I absolutely agree. My input allows for 110 to 135vac. But the question remains: why has the Honda's AC output changed from 125 to 121? And the output is ranging from 118 to126 when it has been a rock solid 124-126?


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## tabora (Sep 6, 2018)

JRHill said:


> But the question remains: why has the Honda's AC output changed from 125 to 121?


Get a second opinion... You said:


JRHill said:


> I was closely watching the system console (Outback Mate3s) and open circuit AC voltage from the generator was slowly roaming from 121vac down to 118 and up to 126.


Do you have a quality multi-meter? Plug it into the EU's outlets and check the voltage at that same point. Are you running in 120V or 240V mode? Is ECO mode on or off?


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## JRHill (Nov 19, 2020)

ECO on for my purposes and it matters not - Eco on or off is the same. 120vac only. I have a Fluke 77 and it follows the AC in voltage.


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## OrlyP (Oct 19, 2021)

That seems like a grey area to me. You've established that this is not normal behavior, even if the output is well within acceptable range. It may just be components inside the inverter going a little out-of-spec that which comes with age. I would keep an eye on it from now on and see if the voltage deviations gets any worse over time.

The trouble with these inverter modules is that they're not user serviceable. The most you can do is check all electrical connections for snugness and if there's any sign of corrosion. Otherwise, there's not much else that can be done.

For now, I think it's still safe for use, given that the output stabilizes once a load is applied. An oscilloscope would be handy to verify if the normally pure sine wave has changed as well. That could indicate a failing part inside the inverter module.


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## tabora (Sep 6, 2018)

JRHill said:


> ECO on for my purposes


FWIW, the manual specifies starting the generator with ECO off during warmup.


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## JRHill (Nov 19, 2020)

tabora said:


> FWIW, the manual specifies starting the generator with ECO off during warmup.


Yeah, I know. The whole purpose of ECO OFF is so the unit can come up to running temp ASAP. But I can start the unit no load, warm it with no load and slow roll the load into it once warmed. Who starts their rig and goes like crazy so it heats up ASAP? Why is your generator any different if you can control the warm-up and loading?


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## JRHill (Nov 19, 2020)

OrlyP said:


> That seems like a grey area to me. You've established that this is not normal behavior, even if the output is well within acceptable range. It may just be components inside the inverter going a little out-of-spec that which comes with age. I would keep an eye on it from now on and see if the voltage deviations gets any worse over time.
> 
> The trouble with these inverter modules is that they're not user serviceable. The most you can do is check all electrical connections for snugness and if there's any sign of corrosion. Otherwise, there's not much else that can be done.
> 
> For now, I think it's still safe for use, given that the output stabilizes once a load is applied. An oscilloscope would be handy to verify if the normally pure sine wave has changed as well. That could indicate a failing part inside the inverter module.


I hate to agree with you but I'm inclined. The other thing is it could be a simple as a trim pot that needs a wash and (safe) wipe up and down. Now that's way to easy, isn't it? And yes, connectors, etc. I was hoping someone would say "Oh, no big deal, kick it on the lower left side while starting." (wink)


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## iowagold (Jan 22, 2020)

JRHill said:


> This is an off-grid blended system of the Honda with an Outback Power solar for charging the batteries during low light. The generator's operation is completely automated. The generator is 4 years old and just shy of 2k hours. Over the last week I have been having problems and noticed something odd this morning. During the programmed 5 minute warm up I was closely watching the system console (Outback Mate3s) and open circuit AC voltage from the generator was slowly roaming from 121vac down to 118 and up to 126. There is no sound change and the engine is running great.
> 
> This really unusual as the unit has always been a rock solid 124-126vac under load or not. Once the unit has warmed up and connected to the system the AC from the unit is rock solid at 121vac. Seems OK but until recently it has always been 4vac higher. The generator's Hz is right on at 60.
> 
> Any ideas about the voltage output?


the generator output is hunting for sync.
try a simple incandescent 60 watt light on each of the L1 and L2 120 vac outlets on the front and see if that helps settle down the generators inverter.

question does the generator voltages check ok as a stand alone not connected?


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## drmerdp (Apr 10, 2018)

Before condemning the generator, check the voltage directly at the generators outlets to check for a voltage irregularity. If voltage is ok at the unit assume a poor connection down stream.

As mentioned, the proper warmup procedure for the EU7000 is eco off, the reason for this is to keep the O2 sensor from fouling. Single wire Narrow band oxygen sensors use .5 volt switching to relay rich or lean to the ECU (GCU in this case) the longer it take to get to 600 to 700 degrees the more likely the sensor can become carbon fouled and less sensitive to fluctuations in free oxygen in the exhaust stream.

A clever way to bypass this would be a normally closed thermal switch of a certain temperature placed somewhere in in proximity to engine heat to keep the eco circuit closed until reaching adequate temp. Then the thermal switch reaches its threshold the switch will open and eco mode will be Turned on.


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## JRHill (Nov 19, 2020)

drmerdp said:


> As mentioned, the proper warmup procedure for the EU7000 is eco off, the reason for this is to keep the O2 sensor from fouling.


I stand corrected. Of course the ECO Off is to warm the engine up ASAP according to the manual. As I mentioned I hate running any engine hard at cold start. I had not pondered the O2 sensor's role in the process. And of course the darned spark arrestor getting occluded faster. I guess I'll just clean it more often until I get the 'cone' installed.


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## iowagold (Jan 22, 2020)

grin the cone of silence (get smart reference)
they work ok!
we use them!
and yes you can run more than one in a long tube to stop the echo in a larger dia exhaust tube
pm if you need links on those.


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## JRHill (Nov 19, 2020)

Confession time. The L5-30 twist lock plug failed on the hot lead and melted the surrounding plastic and overheated the screw clamp and wire. I had disassembled and inspected and snugged it this summer and all was good. Recently, in troubleshooting, I shot the connector with an IR thermometer under load as well as many other places. All good but not.

So the DW is coming home from a trip to the city with two of 'em, If in Home Despot stock.. Replacement happens ASAP this afternoon.

So here is a question for sparktricians: You know the plug. The wire enters the hole and you screw it down with the cleat, wire on one side, pulling it up tight to the prong. But I've always had to give the stranded 10ga stripped wire a good twist or the strands splay out with some strands not being captured - ugly, sloppy and poor workmanship. But with the twist it increases the diameter and the cleat can have quite a tilt with the 10ga one one side. This makes torqueing it a problem as the screw/cleat can strip easily. I've considered a slight tack of solder - only on the ends of the strands, to hold them together (not wicking the solder throughout the stands, just on the end). Then flux cleaning.

Maybe there is a L5 plug out there that has a set screw style clamp but it's not available to me locally. Sheesh, everywhere else in the circuit there are set screw clamps but not on the plug which is the most movable anywhere along the line. This is my weak link.

Input?


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## tabora (Sep 6, 2018)

JRHill said:


> Maybe there is a L5 plug out there


I swear by Hubbell connectors. This one will take up to 8gauge: HBL2611 | Wiring Device - Kellems


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## JRHill (Nov 19, 2020)

tabora said:


> I swear by Hubbell connectors. This one will take up to 8gauge: HBL2611 | Wiring Device - Kellems


Buddy, I can't load this....


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## iowagold (Jan 22, 2020)

they make crimp pins that work well to capture all of the strands.

we modify the eu-7000i with a marine 50 amp twistlock.
ultra hd that way.

solder or tinning the wire is ok...
but the lead will be an issue over time.

maybe silver solder?
then use the dielectric grease.
we use the better 14-30 connectors and do not have an issue.

make sure to torque those screws with a torque screw driver with a new bit.
pm if you need links to the parts and tools.


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## drmerdp (Apr 10, 2018)

JRHill said:


> Confession time. The L5-30 twist lock plug failed on the hot lead and melted the surrounding plastic and overheated the screw clamp and wire. I had disassembled and inspected and snugged it this summer and all was good. Recently, in troubleshooting, I shot the connector with an IR thermometer under load as well as many other places. All good but not.
> 
> So the DW is coming home from a trip to the city with two of 'em, If in Home Despot stock.. Replacement happens ASAP this afternoon.
> 
> ...


“DW” ? Darn woman?

The clamp style wire Terminal has never been a problem for me. It’s the most common terminal in plugs. The twist Your are adding is what’s probably hurting you. The twist has more space to compress leaving the connection more loose.

Leave the wires straight so that the clamp can have more surface area with the strands. It’s best to retighten the connection once or twice with some time for the connection to relax before assembling the rest of the plug. Don’t use a worn screwdriver either, these terminals need to be TIGHT.

I also like Hubbles connectors these days. Eatons arrow head plugs are solid and heavy duty as well, a bit on the larger side though.


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## iowagold (Jan 22, 2020)

i like legrand and marinco.

de wife for dw.
lol
it could be a french thing or german
der wife = dw der is " the " in german.
lol


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