Schneider XW 6848+ with generator question

ELYNN4

I am off the grid and have a question regarding the XW 6848+ with the Conext AGS and a 9KW 1800rpm generator.

When the generator has started and in its three minute warm up period, and the XW is “qualifying” the generator power, the power to the house flickers/blips every 30 seconds or so.  Every so often, maybe once a month, the XW will actually drop the power to the house for a split second.  This is all happening before the generator has completed its warm up period and placed on line.  The power outage is long enough that loads such as the dryer, unit heaters and computer switches are knocked off line and need to be restarted.  This issue also occurs when the generator has completed its charging and is in the cool down cycle.

I never have these issues when the XW is online and the only power source, nor when the generator power has been qualified and is online.  It only happens when the generator is warming up or cooling down - not when it is online.

My question - is there a setting on the XW that can be adjusted to keep these power drops from happening?

Thanks for any suggestions,


Elynn4

Dave Angelini

You are right to be very concerned with this and need to fix it ASAP. It is the generator or grid that will end the life of the transfer relay if not configured properly. Generators are expendables. The output waveform of the genny needs to be stable. It changes with age and condition.
Until you solve this let the genset warm-up before you manually close the breaker.  You have conext insight?

ELYNN4

Thanks Dave - yes I have the Conext Gateway.  The AGS is programmed to let the generator warm up for 3 minutes before it gets put on line.  The AGS is also programmed to let the generator cool down for 2 minutes before it is turned off.

The power blips from the XW only occur when the generator is warming up or cooling down.

The generator input voltage is 243 when warming up - 239 - 241 when under load.  The HZ are 60.1 to 60.3.

Not sure which setting might be causing this issue or if it’s indicative of a relay going bad.

The power is very clean while charging - the charge rate is 79.8 amps.  It fluctuates between 79.6 and 80.1 but the majority of the time it is a constant 79.8.

Thoughts on next steps I should take?

Thanks.

ELYNN4

Dave, what’s got me stumped is that the power blips occur within 30 seconds of starting the generator and continue through the warm up period.  The actual transfer to the generator goes very smoothly.  Then when the generator is finished charging the batteries and enters the cool down phase the power blips start up again.  Very sporadically there will be a longer power blip either during the warm up or cool down phase - no rhyme or reason to it.

Dave Angelini

More detail  !  Do you see AC2 Led go on/off and hear the relay on these 30 seconds. On the local meters screen is there an ac current blip?

When I said generators are expendables, I mean get another generator to test. It almost always is the generator.  A 9 kw gen is really the low end for an XW. Most use much bigger for a 60 amp 240 circuit. You could be overloading even if the breaker setting does not trip.. Distortion in the AC signal is very hard to measure and you need some expensive test equipment.

Sounds wrong to me to be using an electric dryer offgrid with a smaller genset. Please don't tell me the computer is on...  Good Luck!

Graham Parkinson

Perhaps consider adding $400 EG4 Chargeverter (configurable current and voltage 48VDC 5 kW 100A battery charger, runs on 120VAC or 240VAC) and then charge your battery direct from your generator without running the charging current through your inverter. 

That way you can let the inverter just invert. Transients from generator hiccups will have no effect on your household power.

Apparently it lacks an automatic slow ramp-up of charging current though, which would be nice to give your generator time to track with the application of the load.  But you can ramp up charge current manually on it's control panel.

ELYNN4

Dave,

Sorry for not providing enough info:  The AC2 light blinks, indicating that it senses that the generator is running.  Neither the led or the display give any indication that the XW is trying to switch to the generator.  I have not heard the relay click during these blips, but the XW and generator are only 10 feet apart so its really too noisy to hear.  When the transfer does occur the XW display turns from showing the load to three dashes and then the load is transferred to the generator gradually with the display showing the charging current.  Once the generator is placed on line the AC2 led shifts from blinking to steady state.

The dryer is gas fired, it gets bumped off line when the larger power blips occur during warm up and cool down of the generator.

I do have a 6kw generator - I will try putting it on line and see if I have the same issue - thanks!

Graham - thanks for the suggestion I’ll do some research.  Sounds like I should have a backup plan in place in case the XW’s relay goes belly up.  Thanks

Mtnsun

I have a new Xw Pro setup with AGS, I noticed when the generator starts it qualifies the power and then connects to the inverter loads during the warm up period, charging starts after the warm up period ends. 
My old Magnum inverter that I just replaced would start the generator, then after the warm up period was complete, it would qualify, connect loads and then charge.
This could be similar to what is happening to you, is there a setting to make the inverter wait to connect to inverter loads untill after the warm up period?

ELYNN4

Interesting thought Mtnsun.  The generator will be running tomorrow - I’ll check and report back.  There is a timer that begins once the generator power has been quantified and the generator is placed on line.

ELYNN4

Mtnsun - The Gateway shows that the XW remains in the Inverting mode until the generator has completed its warm up phase.  Once the generator is placed on line the Gateway shows that the XW is in the AC  Pass Through mode.

Mtnsun

After watching my generator I realized my warm up phase is not working, I have it set to 300 seconds but it starts charging right away. The cool down cycle does work which is strange. I am still figuring out this new system....
I agree you should try a different generator to see if you get similar issues 
Sorry I was not any help. 

ELYNN4

I was having those same issues with my AGS after I upgraded its firmware - turned out that it was a firmware issue due to my having the XW+ rather than the XW Pro.  Might be worth going back a version on the AGS firmware and see if it solves your issues.

ELYNN4

Mtnsun - my mistake, it was the Gateway firmware not the AGS firmware.

ELYNN4

I put my 6 kw generator on line and have run it through several charge cycles.  The XW is still causing power blips during the warm up and cool down cycles on the generator.  The same as it does with the 9kw.

I’ve noticed on the gateway that the voltage drops from +/- 244 to +/- 241 when the power blips.  I can hear in some of my fans that the XW is adjusting the hz to match the generator’s no load 64 hz.  This cycling continues until the generator is qualified and placed on line.  Once the generator has a load the hz drop to 59.9 and the power blips stop.

I can wrap my head around why this might be happening when the generator is in the warm up cycle.  I can figure out why the XW would do this when the generator is in the cool down cycle.

Any Ideas out there?

Graham Parkinson

Aren't the generator and inverter just doing the same synching dance in the opposite direction during cool down?  Cool down should be to a lower load, causing shifts to higher frequency which will require the inverter to trackback up.

Dave Angelini

Can you try starting the gen with the AC2 breaker off and engage it when warm for charging?
Do the opposite after charging for cool down, Not very hi tech but

You will end up with welded relays of this goes on too long! The 64 hz. is way off frequency for a hybrid like XW. I know it is cold but 64?

If you add my email to insight cloud, I will take a one time look at your system settings. I do not think you have posted them here but I very well could be wrong.  I have been swamped the last 4 months with new clients. I use to have time to read this stuff carefully...

ELYNN4

Graham - when the generator begins the cool down cycle it is immediately taken off line - there is no load on the generator.  At least that is what the Gateway is showing and that is what the generator sounds like.  It is curious…

ELYNN4

Thanks Dave - I’ve got you set up…much appreciated.

Dave Angelini

Brrr.   A client staying warm!  The days are getting longer!  

ELYNN4

Thanks for your expert guidance Dave.

For those interested -  it turns out I had my high end Hz parameters set too low causing the inverter to occasionally disqualify the power during warm up and cool down.  After tuning up the generator - I was getting too much droop between unloaded and loaded and turning the rpm down slightly.  Then adjusting the allowable high side Hz slightly.  The system is happy with the power it’s being supplied with.

I still don’t understand why they care what the Hz of the generator is during cool down - probably a short cut in their programming - but that’s not worth worrying about,

Thanks again Dave Angelini