1ph EPS critical loads backup package for power cuts

Package includes a new sub-board with necessary re-wiring of critical load to the EPS output of the inverter for power during outages.

Please note: This is only available to purchase together with an installed system.

What is a Critical Load Sub-Board?

A critical load sub-board (or panel) is a separate electrical panel installed downstream from your main panel that contains only essential circuits you want to keep powered during an outage—such as refrigerators, medical equipment, lighting, communication devices, and sometimes HVAC fans. Instead of trying to back up your entire home load, this panel isolates and prioritizes critical circuits for battery backup or generator power.

How EPS Setup Works via New Sub-Board for Critical Loads

1. Separate Critical Load Panel Installation:
   The new sub-board is wired by transferring circuit breakers for critical loads from the main panel to this critical loads panel. This keeps backup power focused on select, important circuits rather than the whole house.
2. Power Source Switching (Transfer Switch):
   An automatic transfer switch (ATS) or manual transfer switch is installed between the main supply and critical load panel. In normal operation, the critical load panel gets power from the grid/main panel. When a power cut occurs, the switch automatically disconnects from the grid and connects to the emergency power source, such as battery inverter output or generator.
3. Battery & Inverter Integration:
   A battery bank stores energy, and an inverter converts DC battery power to AC for the critical load panel. The inverter connects to the sub-board, powering only those critical circuits during outages. The batteries are charged by solar, grid, or generator when power is available.
4. Load and System Sizing:
   You must carefully select which loads go on the critical load panel based on your battery and inverter capacity. Common critical loads include refrigeration, lighting, Wi-Fi/communication, and medical devices. This reduces battery size and cost versus whole-home backup.
5. Smart Load Control (Optional):
   Some modern setups use smart load panels or load controllers (e.g., Span, Lumin) that enable real-time monitoring and control of each circuit on your phone or computer, allowing flexible load management during outages.

Advantages of Using a New Sub-Board for Critical Load Backup

• Cost Efficiency: Limits battery and inverter size since only essential circuits are powered.
• Longer Runtime: Batteries last longer powering fewer loads.
• Simplified Installation: Easy to identify and isolate critical loads in a dedicated sub-panel.
• Seamless Transfer: Automatic transfer switches ensure quick and safe switching during outages.
• Expandability: Easy to add more critical loads or storage in the future.