The REFU Elektronik SV27680B is an original electronic module designed for EMI/EMC filtering and AC line conditioning in REFUsol photovoltaic inverters.
Installed in the grid interface section, this board plays a critical role in ensuring power quality, electromagnetic compatibility, and system protection. It reduces high-frequency interference generated by the inverter and protects internal circuits from voltage spikes and transients.
In addition to filtering functions, the board integrates an auxiliary switching power supply, supporting internal inverter electronics.
⚙️ Main Functions
- EMI/EMC filtering on the AC line (common mode + differential mode)
- Reduction of conducted interference toward the grid
- Protection against overvoltage and transient spikes
- AC voltage conditioning and stabilization
- Support for auxiliary power supply circuits
🔍 Technical Features
- Industrial multi-layer PCB with high reliability
- Combined EMI filter topology (inductive + capacitive)
- Integrated surge protection stage (MOV-based)
- Built-in auxiliary switching power module
- Screw terminals for high-current AC connections
- Components sized for industrial power applications
- European manufacturing (Made in Germany)
🔧 Main Components
- Toroidal copper inductors → common-mode filtering
- Film capacitors (Class X/Y) → EMI suppression
- Varistors (MOV) → surge protection
- Integrated switching PSU module → auxiliary supply
- Power capacitors → voltage stabilization
- Screw terminals → AC input/output connections
- SMD components → signal conditioning and control
🔌 Role Inside the Inverter
This board is installed between the power stage and the grid connection, where it:
- Ensures electromagnetic compatibility (EMC compliance)
- Reduces conducted emissions
- Protects the inverter from external disturbances
- Improves system stability and reliability
- Contributes to compliance with CE and industrial standards
⚠️ Technical Notes
- ❌ Not a control or logic board
- ❌ Not a power conversion board (does not perform DC/AC conversion)
- ✔ AC filtering and protection module
- ✔ Includes auxiliary power section (secondary function)
- ✔ Works together with power and control boards
⚡ Typical Faults
- Increased electrical noise or EMC issues
- Grid disturbance errors
- Damaged MOVs due to surge events
- Degraded capacitors affecting filtering performance
- Auxiliary supply instability
📊 Applications
- REFUsol photovoltaic inverters
- Industrial solar power systems
- Grid-connected power electronics
- EMC compliance and filtering stages
📦 Product Condition
- Electronic board (used / refurbished)
- Tested (if applicable)
- Supplied as a professional spare part
💡 Summary
The REFU SV27680B is an essential AC-side EMC filter and conditioning board, responsible for:
✔ Reducing electromagnetic interference
✔ Protecting the inverter and grid interface
✔ Stabilizing AC output quality
✔ Ensuring compliance with EMC standards
👉 A critical component for safe, stable, and compliant inverter operation.
