Frigoboat Merlin II Smart Speed Controller for Danfoss BD35 & BD50 Compressors

The Frigoboat Merlin II Smart Speed Controller automatically adjusts compressor speed to maximize refrigeration efficiency while protecting system electronics. Designed for Danfoss/Secop BD35 and BD50 compressors, the Merlin II continuously monitors system demand and selects the optimal compressor speed for reduced power consumption and improved cooling performance. Integrated diagnostic LEDs provide real-time operating status and fault indication for easy troubleshooting. It installs directly onto the compressor controller for a simple plug-and-play upgrade.

Specifications

• Model: Merlin II
• Part Number: E52152
• Type: Automatic Smart Speed Controller
• Compatible Compressors: Danfoss/Secop BD35F and BD50F
• Voltage: 12V / 24V DC
• Installation: Plug-and-play controller board
• LED Indicators:
  • Green LED: Compressor speed and thermostat status
  • Red LED: Diagnostic fault codes
• Speed Control: Automatic compressor speed selection
• Start-Up Protection: Warm-start ramp-up routine
• Diagnostic Functions: Low voltage, overload, compressor faults, fan/pump faults
• Mounting: Direct controller mounting or remote mounting

Additional Features

• Protects compressor electronics during startup
• Improves overall refrigeration efficiency
• Diagnostic fault indication simplifies troubleshooting
• Compatible with most Frigoboat air-cooled and keel-cooled systems
• Replaces standard manual speed boards

INSTALLATION AND MANUAL

MERLIN II INSTALLATION GUIDE