EG4 6500 EX Bypass feature

[vietxtlife]

Here are some more findings about the smart home rule about when the AC-in contactors should be closed:

I found out that forever reason, in case if the inverters have less than 100-150W load each, at the moment when the AC-in contactors get activated to connect them to the grid, sometimes (about 2 out of 10 times) some but not all go in Fault 60 status (grid feedback protection). Because of that, I've changed the smart home rule a bit to not only check the SOC (or voltage) of the batteries to activate the AC-in contactors, I also check the current load of the AIO's. In case the load is less than 150W for each AIO, I activate a large 240V load, wait about 10 seconds to balance the load between all the AIO's, switch the AC-in contactors to ON, wait again some seconds and deactivate the large load. This solved the sporadic problem with the F60 error! In my case the "large 240V load" is a pump which I can remote control anyway.

It looks like the design of these Voltronic, Axpert Max (MKS2-6500) based AIO's are in general able to feed energy back to the grid - but in most clones this feature is removed in the firmware (like in the EG4-6500EX - I know at least one of these clones which has the grid-interactive feature available for configuration, it's called Phocos AnyGrid model PSW-H-6.5KW-120/48V). I don't really know, why this F60 only happen if the inverters have low load at the moment the grid (or a generator) will be connected. If your connect them to the grid while having idle load, the problem occur every 2nd try, so it depends really on the load! After changing this, I've never seen this problem again (about 20 test cycles so far).

how do you integrate the contactor with your smart home? by the way wow your system set up are so clean, look like pro with years of experience

 

[fmeili1]

how do you integrate the contactor with home assistant? thanks

I'm using OpenHAB but the mechanisms will be the same for Home Assistant.

I use WiFi "Shelly Plus 1 dry contact relays" which I control via OpenHAB. There are different options here. I don't like the cloud based Shelly App (I don't like cloud "phone to home" solutions at all for privacy and I want to keep everything working if internet may be down), that's because I flashed them with Tasmota firmware which connects via MQTT with OpenHAB (here are the Tasmota Shelly Plus 1 instructions). If you don't care about cloud connect, you may use the cloud based specific Shelly binding, which I'm sure is available for HA also.

The Shelly Plus 1 relays drive both contactor coils with 120VAC (the contactors are also available with 24VAC coils).

All in all I use 4 of these Shelly relays to be able to control the following circuits separately:

• battery disconnect via two 600A/80VDC relays (48V MZJ-600A), one Shelly drives two 40A SSR's (relays) which drive the 600A relays (one relay for one battery rack with each 6x100AH batteries)
• AC-in disconnect via the already mentioned 110A/120VAC contactors
• PVRSS via Tigo transmitter (it's available as a set with case and power supply) for PV module level shutdown via Tigo TS4-A-2F PV remote switches
• A complete emergency shutdown which disconnects all above energy sources at once.

I've put everything together in a controller case (together with the RaspberryPi with SolarAssistant) as a central solar controlling and monitoring system. Beside the remote emergency shutdown via Shelly, all components could be disconnected via an internal and an external emergency button and 2 Kidde smoke detectors (with Kidde SM120X relay) with are able to trigger the emergency shutdown, also. Now I have a better feeling to sleep behind this inverter wall because I know, that the whole AIO's will shutdown (while disconnecting every possible energy source) in case of fire or an other emergency. Because all the relays and contactors are normally open (NO), I need a blackstart UPS to drive the controller circuit.

This is how the controller case looks like (3 Shelly [blue color] relays are on the lower right side and the central emergency Shelly relay is located on the upper left side beside the power supply and the breaker). On the bottom you can see the two 40A SSR to drive the two 600A battery relays (they need huge inrush amps for the pick-up coil and the Shelly by itself could not handle this amps). On the upper right there are two buck converters to produce the 5VDC for the RaspberryPi and 12VDC to drive some other relays and the cooling fan. The main power supply with 48VDC is located in the upper left. The 600A relays need 48VDC coil voltage.