API 1000 AH Lipo4 Energy Storage System
August 23, 2019
This system consists of:
3, Magnum 4448 PAE inverters, total AC power is 13.2 kW. Another inverter can be added to the system any time.
1, Magnum system router.
1, Magnum power panel.
2, Schneider 600 vdc, PV charge controllers, for a total of 8.8 kW of solar power.
1, API, 9th generation Li system, complete with BMS, BMS remote display, 2 CAN communication ports, 8, trigger ports that control PV charging, AC charging & auto gen start. 1000 AH @ 51.2 vdc, total of 51.2 kWh.
1, API 80 Li AC charger. Our AC chargers, are specifically designed for Li systems. Very smooth/clean output–power supply quality and 99% efficient.
1, complete system monitoring meter
All necessary system disconnects and circuit breakers.
As you can see we rout everything in conduit and/or gutters. You will also notice that the power flows from left to right. DC enters on the left side. DC charge controller input disconnects to Schneider 600 vdc charge controllers, then to 100 amp DC breakers and the common DC buss. We always design and install systems with service disconnects on both the input and output of all power electronics. This allows for simple and safe troubleshooting should there be a problem in the future.
The common DC buss supplies power to the inverters via their own individual DC main breakers. We do not use inverter chargers as chargers. Just like we do
not recommend AC coupled systems. There are too many potential problems associated with AC coupling. The Magnum power panels normally circuit breaker the inverters AC input. Since we do not use the inverters as chargers we remove these circuit breakers and replace them with individual inverter 20 amp output breakers. This is a current limiting device and these breakers will trip, prior to the inverter going to overload or worse yet, potentially frying. Another important thing to remember with stacked inverters is if they are not electrically isolated on the output you can have a catastrophic failure when the system is initiated and first started up. Especially Magnum, we have seen many, many times a clock stacking failure. This means the inverters are not in sync and they will fight each other with the eventual failure of at least one inverter, depending on how many are in the system. By installing separate 20 amp output breakers we are able to keep each inverter AC output isolated until we verify that they are in sync. If we see a clock stacking failure, we simple turn the system off and restart it via the router until the clock stacking failure disappears verifying the system is running properly. Once we see that the router is OK and no error message is displayed, we turn on each inverter 20 amp output breaker one at a time. This saves us the headache of having to replace brand new inverters because of a communication error.