Dear members of the DIY Solar Forum,
I hope you are all having a wonderful day. Several weeks ago, I embarked on an exciting DIY project aimed at creating a 10kVA solar system, powered by two 10kWh LiFePO4 batteries connected in parallel. The system comprises various components, all from a single manufacturer, with the exception of the panels, which are sourced from a different manufacturer, including:
1. A 10kVA inverter equipped with a 120A built-in charge controller.
2. Two 10kVA 48V LiFePO4 batteries connected in parallel.
3. An additional 120A charge controller.
4. A set of twenty 450W used solar panels, thoughtfully organized into two sets.
Throughout the assembly process, I meticulously ensured precision and attention to detail. Despite the inverter's impressive 120A MPPT built-in capacity, I decided to supplement it with an additional 120A MPPT controller to provide an extra margin of safety.
The solar panels were thoughtfully configured - one set arranged in a 4S, 3P configuration, connected to the charge controller, and the other set organized in a 4S, 2P configuration. Each series string was protected with a 10A fuse holder before parallel connection, and I also incorporated essential surge protection devices (SPDs) and circuit breakers after the parallel connection of each set.
Initially, the system operated smoothly, efficiently harnessing solar energy to charge the batteries during daylight hours. However, an unexpected issue surfaced when I decided to deactivate both the external MPPT circuit breaker and the inverter's built-in MPPT circuit breaker. To my dismay, when I attempted to reactivate the inverter's built-in MPPT breaker, an unanticipated event unfolded - the inverter suddenly experienced a critical failure.
Upon a thorough examination, two issues became evident:
i. The inverter had malfunctioned.
ii. The built-in fuses of the batteries had blown.
Interestingly, after replacing the fuses of the batteries, one of them resumed flawless operation, while the other exhibited erratic behavior, accompanied by peculiar sounds.
Although I had a hunch that one of the batteries might have been the root cause of the issue, I remain open to the possibility of other factors contributing to this puzzling situation.
After engaging in discussions with the seller, they kindly facilitated the replacement of the faulty inverter with a new one, albeit without the built-in MPPT feature. Furthermore, they supplied a brand-new external MPPT. The subsequent reinstallation of these components has restored the system's functionality.
As it stands, I currently possess two 10kWh LiFePO4 batteries, two 120A charge controllers, and one 10kVA inverter (without built-in MPPT), all from the same manufacturer.
In light of this scenario, I turn to this esteemed forum to seek your collective wisdom and expertise. What could have possibly gone awry in my initial setup? Could it have been due to a defective battery or inverter, or is there a critical aspect of installation that may have eluded my attention?
While I have entertained the suspicion that one of the batteries may have been a contributing factor, I remain open to alternative explanations.
I am truly grateful for your time and assistance in unraveling this intriguing puzzle and, ultimately, in helping me avert any potential recurrences in the future.
I hope you are all having a wonderful day. Several weeks ago, I embarked on an exciting DIY project aimed at creating a 10kVA solar system, powered by two 10kWh LiFePO4 batteries connected in parallel. The system comprises various components, all from a single manufacturer, with the exception of the panels, which are sourced from a different manufacturer, including:
1. A 10kVA inverter equipped with a 120A built-in charge controller.
2. Two 10kVA 48V LiFePO4 batteries connected in parallel.
3. An additional 120A charge controller.
4. A set of twenty 450W used solar panels, thoughtfully organized into two sets.
Throughout the assembly process, I meticulously ensured precision and attention to detail. Despite the inverter's impressive 120A MPPT built-in capacity, I decided to supplement it with an additional 120A MPPT controller to provide an extra margin of safety.
The solar panels were thoughtfully configured - one set arranged in a 4S, 3P configuration, connected to the charge controller, and the other set organized in a 4S, 2P configuration. Each series string was protected with a 10A fuse holder before parallel connection, and I also incorporated essential surge protection devices (SPDs) and circuit breakers after the parallel connection of each set.
Initially, the system operated smoothly, efficiently harnessing solar energy to charge the batteries during daylight hours. However, an unexpected issue surfaced when I decided to deactivate both the external MPPT circuit breaker and the inverter's built-in MPPT circuit breaker. To my dismay, when I attempted to reactivate the inverter's built-in MPPT breaker, an unanticipated event unfolded - the inverter suddenly experienced a critical failure.
Upon a thorough examination, two issues became evident:
i. The inverter had malfunctioned.
ii. The built-in fuses of the batteries had blown.
Interestingly, after replacing the fuses of the batteries, one of them resumed flawless operation, while the other exhibited erratic behavior, accompanied by peculiar sounds.
Although I had a hunch that one of the batteries might have been the root cause of the issue, I remain open to the possibility of other factors contributing to this puzzling situation.
After engaging in discussions with the seller, they kindly facilitated the replacement of the faulty inverter with a new one, albeit without the built-in MPPT feature. Furthermore, they supplied a brand-new external MPPT. The subsequent reinstallation of these components has restored the system's functionality.
As it stands, I currently possess two 10kWh LiFePO4 batteries, two 120A charge controllers, and one 10kVA inverter (without built-in MPPT), all from the same manufacturer.
In light of this scenario, I turn to this esteemed forum to seek your collective wisdom and expertise. What could have possibly gone awry in my initial setup? Could it have been due to a defective battery or inverter, or is there a critical aspect of installation that may have eluded my attention?
While I have entertained the suspicion that one of the batteries may have been a contributing factor, I remain open to alternative explanations.
I am truly grateful for your time and assistance in unraveling this intriguing puzzle and, ultimately, in helping me avert any potential recurrences in the future.
