Sol-ark 15k Maximum Current?

[dreancestere]

I'm trying to figure out how my electric use relates to what the maximum current the Sol-ark 15k will convert from DC (i.e., PV or battery) to AC (i.e., load). The spec sheet for it says:

Max. Output Current: 62.5A
Real Power, max continuous (batteries only, no PV): 12,000W (50A @ 240V)
Max Output Fault Current (5s): 94A with PV, 75A (batteries only, no PV)
Max Output Fault Current (100ms): 120A
Max. Grid Passthrough Current: 200A



My silly question is what counts as current? Looking at the graph on the Equipment tab of solarkcloud.com for the inverter's I-ac-L1 and I-ac-L2, I've got good chunks of time with each of those at upper-30s amps. Are those I-ac-L1 and I-ac-L2 values what's being talked about with the specs, above? If I were off-grid, and if those L1/L2 values are what I should be referencing, would I add the two legs (so roughly >75A) and have to worry about exceeding the current rating? Or, would it be more correct to look at the load's P-Load_L1 and P-Load_L2 and dividing them by Load Voltage L1 and Load Voltage L2, respectively, to get the current?

 

[DIYrich]

Each Line (L1 or L2) can have max 62.5a (continuous) from pv+battery.

Note: There is a limit on how "unbalanced" the lines can be. If you are drawing the max 62.5a on L1, you should probably be drawing at least 50a from L2 at the same time.

 

[Helios605]

62.5A x 240V = 15kW DC to AC
62.5A x 120V per leg

Peak apparent (surge) power = 24kVA 10s, 30kVA 100ms

Fault current is derived from DC power source (PV + Battery) along with what the Caps can provide for surge power. Don’t confuse this fault current limit as an unclaimed capability to convert more DC to AC continuous power. When a surge hits in while in off grid mode, more current passes through the converters but voltage may temporarily vary until it reaches the AC side. It isn’t sustainable, hence the lights possibly flickering and the drastic difference in 10s vs 100ms.

Here’s a nugget as well. For those who don’t read the manual and install their 500mA RSD/RSS transmitter on pins 15&16 meant for 100mA only, this can inadvertently drain your Caps (if it doesn’t short circuit the 12V bus) leaving you vulnerable for less fault current protection during load side surges. Hence you may get an AC overcurrent fault before you get the precursor AC overload fault.

If you don’t have enough sustainable power (PV + Battery) in off grid, you’ll trigger the precursor AC Overload fault unless your startup load surge power is high enough for an overcurrent fault. As @DIYrich says, unbalanced loads in off grid can also trip an AC Overload fault leading to more AC overcurrent faults over time

If you’re pulling 30+ AC amps per leg continuously in off grid that shouldn’t be a problem, unless your batteries can’t handle the max 275A DC. Make sure to use both parallel posi and negative batt terminals and stay away from single conductors connected to a Y bus bar. I’m sure my last comment will prompt someone to argue about the Y bus bar, it never fails.