Procedure to turn-on / off my solar system

[z_zk_z]

Is there a document that describes the procedure for turning a solar system on & off (energizing & de-energizing)? My solar system includes two strings of 445 watt solar panels (9 panels in series, 450 volts total each, ~10 amps each), 6 EG4-LL batteries in parallel (48V, 100AH each with display), and a single EG4 6500EX-48 inverter. It seems, I first turn on the BMS of each battery then close their built-in circuit breaker (or do I do it in reverse???), then turn on the inverter, followed by closing the DC contacts of the two solar panel strings. 2nd question- Each battery has a built-in current limiting resistor and I want to know when those resistor switch-in to limit the in-rush current to the inverter, and switch-out. Thanks

 

[tonyg]

As far as I know, the basic order is turn on the battery switch, which should turn on equipment such as inverter & mppts, them turn the switch for the panels.

When you want to turn off, do it in reverse.

 

[LydMekk]

Yeah - battery - on switch on inverter if needed - panels then the loads.
In reverse when turning all off.

 

[timselectric]

Ditto

 

[crossy]

Yup ^^^

You may want to consider an inverter pre-charge arrangement if your BMS doesn't already have one.

 

[tashabay716]

I had the same question as Z. Thanks for the answers. Same EG4 set up BTW

 

[timselectric]

Yup ^^^

You may want to consider an inverter pre-charge arrangement if your BMS doesn't already have one.

EG4 server rack batteries have built-in pre charge circuits.

 

[Shimmy]

Will the pre-charge resistor in each battery engage for minor differences in string voltages?

With multiple strings, do you engage a common DC isolator switch (generally not load-break rated) prior to closing the first battery/string?

Should you isolate all chargers prior to energizing the inverter?

 

[timselectric]

Each battery goes through a pre charge cycle, when turned on. The first one on, should take care of it.

 

[Shimmy]

Each battery goes through a pre charge cycle, when turned on. The first one on, should take care of it.

The pre-charge logic isn't current-based?

 

[timselectric]

No
I don't believe so.
It's just a timed event, was my understanding.

 

[crossy]

No
I don't believe so.
It's just a timed event, was my understanding.

Yeah, don't know about the EG4 but the Seplos BMS just uses a 51R resistor (48V pack) and an adjustable timer up to 5 seconds (default is 2 seconds).