Professional repair kit specifically designed to resolve the E5-1 Relay Error commonly found in OMRON KP Series photovoltaic inverters. The kit includes the main power relays and safety relays typically involved in failures of the inverter's Grid Relay Circuit and AC grid connection system.

The E5-1 error is one of the most frequent faults affecting OMRON KP100L, KP125L, and KP150L solar inverters and is often caused by worn AC output relays, welded contacts, relay coil failures, or deterioration of the relay verification circuitry.

Preventive or corrective replacement of the relays included in this kit can often restore full inverter functionality without replacing the entire power board, reducing maintenance costs and system downtime.

🔄 Compatibility

Compatible with:

• OMRON KP100L
• OMRON KP125L
• OMRON KP150L

📦 Kit Contents

• FT K3AB012W-PS Power Relay
• FT K3LAB012W-PV Relay
• IEC/UL 60384-14 Certified Safety Relays
• Components also suitable for OMRON AC Power Board repairs

⚙️ Technical Specifications

• Coil Voltage: 12 VDC
• Relay Type: Power and Safety Relays
• Designed for photovoltaic inverter applications
• High switching capacity
• IEC and UL certified components
• Compatible with Grid Relay circuits
• Suitable for continuous-duty inverter operation
• Professional maintenance replacement parts

🔧 Main Functions

• Utility grid connection management
• Safety disconnection during fault conditions
• Anti-islanding circuit operation
• Grid relay status monitoring
• Inverter startup sequence control
• AC load switching
• AC output stage protection
• Relay verification and safety testing

🔌 Purpose and Operation

This repair kit is intended for photovoltaic inverters displaying the following fault:

E5-1 – Relay Error / Grid Relay Error

This error is commonly associated with:

• Worn grid relays
• Welded relay contacts
• Relays failing to energize correctly
• Failed relay self-test verification
• Grid connection circuit faults

Replacing the relays often restores proper inverter startup and grid connection functionality.

🧩 Role Within the Inverter System

The relays included in this kit form part of the inverter’s primary safety system responsible for connecting and disconnecting the inverter from the electrical grid.

During operation:

1. The inverter checks grid quality and availability.
2. Performs relay self-tests.
3. Closes the power relay contacts.
4. Begins exporting energy to the grid.

If any relay fails the verification process, the inverter generates an E5-1 error and stops energy production as a safety measure.

⚠️ Typical Faults and Symptoms

Welded Relay Contacts

Symptoms:

❗ Relay remains closed during self-test
❗ Safety verification failure
❗ E5-1 error generation

Oxidized Contacts

Symptoms:

❗ Increased contact resistance
❗ Unstable grid connection
❗ Intermittent inverter operation

Open Relay Coil

Symptoms:

❗ Relay fails to switch
❗ Startup failure
❗ No grid connection

Mechanical Wear

Symptoms:

❗ Reduced switching reliability
❗ Delayed operation
❗ Intermittent faults

Noisy or Intermittent Relays

Symptoms:

❗ Repeated clicking during startup
❗ Continuous connection attempts
❗ Unstable operation

Grid Connection Failure

Symptoms:

❗ Inverter remains in standby mode
❗ Grid connection alarms
❗ No power export

🚨 Related Errors Potentially Resolved

Replacing the relays included in this kit may help resolve:

• E5-1 Relay Error
• Grid Relay Fault
• Relay Check Error
• AC Relay Fault
• Relay Verification Error
• Grid Connection Error
• Mains Relay Failure
• Anti-Islanding Fault
• Startup Relay Error

Error descriptions may vary depending on inverter firmware version.

🛠 Applications

• Repair of OMRON KP Series photovoltaic inverters
• Resolution of E5-1 relay faults
• AC Power Board refurbishment
• Preventive maintenance of solar inverters
• Commercial and industrial photovoltaic systems
• Specialized inverter repair workshops
• Solar plant maintenance operations

✅ Benefits of Repair

• Dedicated solution for E5-1 errors
• Lower cost compared to replacing the complete power board
• Fast inverter restoration
• Improved operational reliability
• Extended inverter service life
• Reduced photovoltaic system downtime
• Ideal for preventive and corrective maintenance

🟢 Summary

The OMRON KP100L / KP125L / KP150L E5-1 Error Repair Kit is a professional relay replacement solution designed to repair one of the most common faults found in OMRON KP Series photovoltaic inverters. Featuring a complete set of AC power and safety relays, this kit helps restore reliable grid connection, eliminate E5-1 relay errors, reduce maintenance costs, and extend the operational lifespan of commercial and industrial solar inverter systems.