The OMRON PWB (ACF) 1177359-60 is an original AC Filter Board used in OMRON KP100L, KP125L, and KP150L three-phase photovoltaic inverters. This board functions as an EMI/RFI suppression and AC output filtering module, positioned between the inverter power stage and the utility grid.

Its primary purpose is to reduce electromagnetic interference generated during high-frequency switching operations, ensuring compliance with EMC regulations and improving the quality of the power delivered to the grid.

The board incorporates high-current toroidal inductors, EMI suppression capacitors, harmonic attenuation components, and protective circuitry designed to minimize conducted emissions, radio-frequency interference, and unwanted harmonics generated during the DC/AC conversion process.

As a critical part of the inverter's AC output section, the filter board contributes to system stability, electrical safety, and overall operational efficiency.

⚙️ Technical Specifications

• Manufacturer: OMRON
• Board Model: PWB (ACF)
• Part Number: 1177359-60
• Type: AC Filter Board
• Application: Grid-connected photovoltaic inverters
• Main Function: AC-side EMI/RFI filtering
• Integrated high-current toroidal inductors
• EMI suppression capacitors
• Harmonic attenuation circuitry
• Grid-side and inverter-side connections
• Internal inverter installation
• Original OMRON spare part

Compatibility

• OMRON KP100L
• OMRON KP125L
• OMRON KP150L

🔧 Main Functions

EMI Filtering (Electromagnetic Interference)

Reduces electromagnetic noise generated by the high-frequency switching of inverter IGBT power modules.

RFI Filtering (Radio Frequency Interference)

Prevents radio-frequency disturbances from propagating through the electrical grid and affecting nearby equipment.

Harmonic Reduction

Helps limit unwanted harmonic components generated during DC/AC power conversion.

AC Output Stabilization

Improves the quality of the power injected into the utility grid by providing cleaner and more stable waveforms.

Power Electronics Protection

Reduces electrical stress on inverter components and connected grid equipment.

🔌 Purpose and Operation

The AC Filter Board represents the final power-conditioning stage before energy is exported to the electrical grid.

Its purpose is to:

• Eliminate electromagnetic interference
• Improve AC output quality
• Ensure EMC compliance
• Reduce electrical noise
• Protect inverter electronics
• Support stable grid connection
• Enhance overall system reliability

Without this board, the inverter could generate excessive electromagnetic emissions and may fail to meet utility grid connection requirements.

🧩 Role Within the Inverter System

Inside OMRON KP-series inverters, the board functions as:

• AC output filter
• EMI/RFI suppression module
• Harmonic attenuation stage
• Grid interface filter
• Passive high-frequency protection system

It operates in conjunction with:

• AC power board
• IGBT power modules
• Main control board
• Grid monitoring system
• Grid connection relays

⚠️ Typical Faults and Symptoms

Damaged Inductors

Symptoms:

❗ Excessive heating
❗ Electrical noise
❗ Grid connection faults
❗ Reduced inverter efficiency

Degraded EMI Capacitors

Symptoms:

❗ Increased EMC interference
❗ Random shutdowns
❗ Intermittent faults
❗ Operational instability

Loose or Oxidized Connections

Symptoms:

❗ Intermittent power production
❗ Overheated terminals
❗ Voltage drops
❗ Unstable operation

Failed Protection Components

Symptoms:

❗ Failure to connect to the grid
❗ Inverter shutdown
❗ Protection alarms

Surge Damage

Symptoms:

❗ Burnt components
❗ Internal short circuits
❗ Permanent board failure

🚨 Possible Associated Errors

A malfunctioning AC filter board may result in:

• Grid Fault
• AC Output Fault
• Ground Fault
• Over Current AC
• EMI Filter Error
• Grid Connection Error
• Grid Synchronization Error
• No Utility
• Islanding Detection Error
• Frequent grid disconnections
• Unstable energy production

In some cases, the fault may not generate a specific error code but may cause repeated grid disconnections, reduced output power, or unstable inverter operation.

🛠 Applications

• Repair of OMRON KP-series photovoltaic inverters
• Replacement of defective AC filter boards
• Restoration of EMC compliance
• Industrial photovoltaic inverter maintenance
• Grid connection troubleshooting
• Refurbishment of solar power conversion systems

💡 Advantages

✔ Original OMRON component
✔ High-current industrial design
✔ Effective EMI and RFI suppression
✔ Improved grid power quality
✔ Supports EMC regulatory compliance
✔ Protects inverter power electronics
✔ Enhances system reliability and operational stability

🟢 Summary

The OMRON PWB (ACF) 1177359-60 AC Filter Board is an essential EMI/RFI filtering module used in OMRON KP100L, KP125L, and KP150L photovoltaic inverters. Equipped with high-current inductors, EMI suppression capacitors, and harmonic filtering components, it improves power quality, reduces electromagnetic interference, protects inverter electronics, and ensures stable and compliant grid connection for photovoltaic energy systems.