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Aims Inverter Charger Fault When Automatic Transfer to Inverter While Aims SCC "ON"

TedH

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Jun 5, 2020
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Several weeks ago, I went 'operational' (in my driveway) with my 1500watt solar with a 60amp Aims Solar Charge Controller into my upsized 15kW Lifepo4 battery bank.
This weekend, the Aims inverter/charger flipped from battery to shore/charge when the batteries dropped to 24v (as it should). This occurred overnight. The inverter/charger continued to charge the system into the morning when the solar charge controller started generating power into the battery bank.

Mid afternoon on Monday, the inverter/charger 'faulted' (it essentially stopped charging and would not flip back to inverter). After checking everything, I turned off the solar panel breakers, reset the load and restarted the inverter. It ran in charger mode for 3-5 minutes and then successfully changed to inverter mode. I then turned on the solar panel breakers so solar could replace power that gets consumed by several appliances.

I suspect the inverter/charger will NOT change from charger to inverter if there is a secondary power source (solar charge controller or another charger) producing power. Both products are Aims. In the product literature, there is no mention of concerns about simultaneous operation of charger, change to inverter while solar controller is producing power.

Has anybody had this experience with Aims products? Since I don't have external relays to suspend one or the other when inverter/charger changes modes, I may have to come up with an automated solution (relay).
 
I am checking to see if I can limit solar charge controller producing power once the batteries reach 27.6v. I think the power from solar charge controller is causing the inverter/charger fault when ATS attempts to perform the automatic switch.

Also, I may boost the charging amps to complete the inverter/charger charging cycle faster so that it finishes overnight vs. running into daytime.
 
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UPDATE:

The more I considered what I am trying to prevent (to avoid BOTH the inverter/charger and solar charging batteries at same time and causing inverter/charger fault when it flips from charge to inverter), I am inclined to FIRST, increase the DC charging amps output to max on the inverter/charger. If the batteries reach float, there really should be no issue as SCC DC amps should also be very low at that time since the bank will be charged.

Will advise on outcome.
 
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I assume you had on over voltage fault. I see this occur when BMS stops the charge but the AIMS charger is in fast charge mode. It must hit the 16V limit. Alter 1 minute it goes into fault mode with the constant beep.
 
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