• Code: SC551-03
• Description: Edge NC Sensor Short-circuit AD value: 0-13 (FB voltage: 0.000V-0.041V) is detected for specified seconds continuously. Detection period: 100 ms, detection frequency: 10 times or more.
• Causes: • NC sensor short-circuit • Connector disconnected
• Remedy: • Replace the NC sensor. • Reset the connector. • Replace the connector. • Replace the fusing unit.

• Code: SC552-02
• Description: Fusing Edge Thermopile Does Not Reload When the fusing edge thermopile does not reach a predetermined temperature for specified seconds consecutively.
• Causes: • Thermopile lens dirt • Thermopile modification, float • Outside input voltage guarantee • After excessive temperature rise prevention unit operation
• Remedy: • Replace the thermopile. • Make sure that the input voltage is within acceptable limits. • Replace the fusing unit.

• Code: SC552-03
• Description: Fusing Edge Thermopile Does Not Reload Heating edge reload permission temperature not reached after heater 1 ON for specified seconds.
• Causes: • Thermopile lens dirt • Thermopile modification, float • Outside input voltage guarantee • After excessive temperature rise prevention unit operation
• Remedy: • Replace the thermopile. • Make sure that the input voltage is within acceptable limits. • Replace the fusing unit.

• Code: SC552-05
• Description: Fusing Edge Thermopile Does Not Reload (Low Voltage) When the fusing edge thermopile does not reach a predetermined temperature for specified seconds consecutively.
• Causes: • Thermopile lens dirt • Thermopile modification, float • Outside input voltage guarantee • After excessive temperature rise prevention unit operation
• Remedy: • Replace the thermopile. • Make sure that the input voltage is within acceptable limits. • Replace the fusing unit.

• Code: SC552-06
• Description: Fusing Edge Thermopile Does Not Reload (Low Voltage) When the fusing edge thermopile does not reach the permission temperature of heat edge reloading for specified seconds continuously.
• Causes: • Thermopile lens dirt • Thermopile modification, float • Outside input voltage guarantee • After excessive temperature rise prevention unit operation
• Remedy: • Replace the thermopile. • Make sure that the input voltage is within acceptable limits. • Replace the fusing unit.

• Code: SC553-00
• Description: Fusing End Thermopile High Temperature Detection (software) Above a predetermined temperature detected for specified seconds continuously. Detection period: 100ms, detection count: 10 times or more.
• Causes: • Triac short-circuit • IOB defective • BCU defective
• Remedy: • Replace the IOB. • Replace the BCU. • Replace the fusing unit.

• Code: SC554-01
• Description: Fusing End Thermopile High Temperature Detection (hardware) In the event of an error
• Causes: • Triac defective (short-circuit) • Engine controller defective • Heating edge thermopile defective • Fusing control software: out of control
• Remedy: • If the triac is defective, replace the AC power supply board. • If necessary, replace the BCU or heating edge thermopile.

• Code: SC554-02
• Description: Fusing End NC Sensor High Temperature Detection (hardware) In the event of an error
• Causes: • Triac defective (short-circuit) • Engine controller defective • Heating edge thermopile defective • Fusing control software: out of control
• Remedy: • Attach the new fusing unit, then run SP-5-810-002. • If necessary, replace the BCU or Fusing edge NC sensor.