Urgent - Troubleshooting Trouble with new inverter, please help

[SooFilthy]

I purchased the Schneider electric SW4048 inverter I previously discussed in other posts. I rewired from previous 12V outback system to 48 volt. Everything has been running just fine for several weeks. Suddenly tonight the inverter started turning on and off cyclically every 1-2 seconds.

What i have done so far:
I have checked the battery bank, and both banks are reading 50.8 V.
I have shut all the breakers to the house off and restarted
I have reset the whole inverter. There are currently no faults listed.
The first time this started tonight, I brought it back online with a load in place. Now I cannot get it to turn on.

Can anyone help? Does anyone know anything about this pulsing?

please forgive me if this is a little disjointed. It is being transcribed by a helper.

*edit: it turned back on for no known reason, while I was exploring the settings on the system control panel. I turned off everything and slowly turned them back on. The system is currently on, bearing a load without shutting off, but I am concerned about this recurring.

[Mike90250]

It sounds like the batteries are discharged and cannot sustain any load.

Use a voltmeter on the battery terminals and turn the inverter on. If the voltage goes below 46V the inverter will turn off.

Repeat the test with the voltmeter at the inverter terminals, does the voltage sag at the inverter ?

What size is the battery bank ? What charges the batteries ? How many watts ?

[SooFilthy]

Thank Your for replying
My batteries are 1275 on hydrometer, and measuring 50.8V by volt meter with everything off. Now with everything on they read 50.5 at the terminals of battery and inverter. I am currently on AC OUT L2, and I would like to avoid bringing down the power in the dark. Will it be safe on L2 until morning? I can then bring it down and test the sag in daylight.

My my batteries are 16 batteries in two strings. 6v 225 amp hour lead acid,. Charged by 2000 watts solar array or 5700 watt generator. No grid tie in.

[extrafu]

Send Schneider an email about it - they are class act and respond quickly. I wrote them many emails and even had a 1 hour phone call with them - always had the right answers from them.

[jflorey2]

I purchased the Schneider electric SW4048 inverter I previously discussed in other posts. I rewired from previous 12V outback system to 48 volt. Everything has been running just fine for several weeks. Suddenly tonight the inverter started turning on and off cyclically every 1-2 seconds.

Dumb question. Is search mode enabled?

[SooFilthy]

It's not a dumb question... after rereading your comment, I am unsure which question you are suggesting is dumb. The search mode is disabled, so it shouldn't have been search pulses. Thank you for directing me to reread this section of my manual.

Thank you Mike, I think you were correct. When I tested the sag during daylight, it dropped to 44V at the battery terminals during inverter reboot. My plan is to increase my solar array to 4000w and add another string of 8 batteries to the bank. Do you think this will solve the issue?

[extrafu]

I think you got jflorey2's message wrong. It's not your question that is dumb, but he asked a what may be "an obvious one".

[SooFilthy]

Thank you for pointing that out. You may be correct. Shorthand internet grammar FTW. I have rewritten my reply. Thank you

[jflorey2]

It's not a dumb question... after rereading your comment, I am unsure which question you are suggesting is dumb.

Sorry, my question was dumb because it's probably not search mode. But the behavior you describe - "turning on every 1-2 seconds" sounds exactly like search mode so I thought I would ask.

[SooFilthy]

I apologize for misunderstanding your intent initially. I had never used search mode since we are off grid residential and it isn't an appropriate setting for the fridge, so I am not terribly familiar. I am still uncertain how it could've turned on, but it is possible I ended up in default settings now that I see what I described does resemble search mode. This is very helpful, and since I have returned all my settings to my normal, I have not seen this happen again. I may experiment this evening and turn on search mode, bring down the inverter and see if I can duplicate the situation with a low load. If this is what happened, then it would mean nothing is broken, and I need to ensure a larger load anytime I am rebooting. Thank you for your initial question, because it may prove highly helpful.

[Matrix]

I just skimmed thru this so please forgive if you have already gotten it solved or if this has already been tried. When setting the low voltage cut off for the inverter, what is the setting. If set for 48v for cut off, every time you apply a heavy load, especially a load that has a start up surge (fridge, well, etc) the voltage will dip below the LVCO for a few seconds and the inverter will shut down. Are you getting any warnings or faults on the screen panel of the SCP or Combox? What are those warnings or faults?

You may want to set your LVCO to 45.8v and set the cut off delay to about 45 seconds. This will keep the inverter from cutting off when large loads are running or surge loads temporarily sag the voltage below a higher LVCO. Good Luck. Your Mileage may Vary