23 Dec
Uncategorized

Do You Know Why We Need to Use Two Pairs of Red/Black DC Terminals on Big-Wattage Inverters?

Indeed, if only one pair of red/black DC terminals were on the large inverters, the cost would be down.

But as the high-quality inverters we made, we can not do that.

(check the video here https://www.youtube.com/shorts/x1a1MPWtcw4)

Because for large-wattage inverters, the second pair of DC positive and negative terminals plays a critical role in ensuring efficient power delivery and reducing voltage drops. Here’s how they are typically used and where they go:

Purpose of the Second Pair of Terminals:

  1. Reducing Current Load on Cables: Large inverters require higher current at the DC input to deliver significant AC power. By using a second pair of terminals, the total current is distributed across multiple cables, reducing the load on each cable and minimizing heat generation and resistance losses.
  2. Improving Voltage Stability: A single pair of cables can experience voltage drops due to resistance, especially over longer runs. Adding a second pair of terminals allows for parallel connections that reduce the total resistance, maintaining a more stable DC voltage at the inverter input.
  3. Enhancing Safety: Splitting the current across multiple cables can also reduce overheating and the risk of damage to a single cable or terminal.

Where They Are Going:

The second pair of terminals is typically connected to:

  1. The Same Battery Bank:
    • Both pairs of cables (positive and negative) are connected to the same DC power source, such as a battery bank or a solar charge controller. This ensures that the current drawn is distributed evenly.
  2. Parallel Batteries:
    • In setups with multiple batteries in parallel, the second pair of terminals might connect to a different battery in the same bank. This helps balance the load across the batteries, improving their lifespan and performance.
  3. Busbars:
    • If the system uses a busbar (a centralized connection point), the second pair of terminals might connect directly to the positive and negative busbars, which aggregate connections from multiple batteries.
  4. DC Distribution Panel:
    • In some cases, the second pair might connect to a DC distribution panel, which serves as an intermediary for routing power from multiple sources to the inverter.

Key Considerations:

  • Cable Sizing: Ensure that all cables are appropriately sized for the total current to prevent overheating and losses.
  • Proper Connections: Secure and clean connections at the terminals are crucial to avoid resistance build-up.
  • Fusing: Each pair of cables should be individually fused for protection against short circuits.

This dual-terminal configuration is a design enhancement for handling the high current demands of big-wattage inverters safely and efficiently.