ABB SF810INT Flame Detectors: Engineering Troubleshooting and Solutions

Introduction
In industrial combustion systems, reliable flame detection is crucial for safety and process stability. ABB SF810INT series flame detectors—including SF810INT-LOS-IR-NQ-C-W, SF810INT-LOS-IR-TL-L-C-W, SF810INT-LOS-UVIR-T-L, and SF810INT-LOS-UV-T—are widely used in boilers, furnaces, and chemical reactors to monitor infrared and ultraviolet flame signals. Despite their robust design, engineers frequently encounter operational issues such as signal loss, false alarms, and unstable readings. This article focuses on these common problems from an engineering perspective and provides practical troubleshooting and maintenance solutions to ensure system reliability.

1. Typical Applications and System Context

The SF810INT detectors are designed for:

• Oil, gas, and coal-fired industrial boilers

• Furnaces in chemical processing and metallurgical plants

• High-risk environments requiring precise combustion monitoring

In these applications, flame detection ensures that control systems can respond immediately to flame presence or failure. Misinterpretation of signals can lead to safety shutdowns or unplanned downtime. Understanding both the operational scope and the engineering boundaries of these detectors is essential.

2. Common Engineering Issues

2.1 No Flame Signal

Causes:

• Misalignment of detector optics relative to the flame axis

• Dirty or scratched optical windows reducing IR/UV transmission

• Unstable power supply or electrical interference

Solutions:

• Re-align the detector along the burner axis and verify signal strength

• Clean or replace the optical window, following manufacturer guidelines

• Check electrical wiring, grounding, and ensure stable DC supply

2.2 False Alarms

Causes:

• Reflected IR or UV radiation from furnace walls

• Nearby external IR/UV sources interfering with detection

• Incorrect sensitivity or response time configuration

Solutions:

• Adjust sensitivity settings according to fuel type and flame size

• Use physical shielding to prevent stray light from entering the detector

• Conduct routine functional testing after configuration changes

2.3 Intermittent or Unstable Output

Causes:

• Loose electrical connections or corroded terminals

• Mechanical vibrations or unstable mounting brackets

• Flame instability caused by fuel variability

Solutions:

• Secure all electrical connections and check for corrosion

• Install vibration-damping mounts and verify alignment

• Monitor combustion conditions and adjust burner operation parameters

3. Installation Best Practices

• Mount detectors on stable brackets with proper orientation toward the flame

• Avoid reflective surfaces near the detector that may cause false readings

• Ensure proper environmental protection for outdoor installations

• Maintain recommended distances between multiple detectors to prevent cross-interference

4. Electrical and Communication Considerations

• Use shielded and grounded cables to reduce electromagnetic interference

• Verify voltage supply meets manufacturer specifications

• Check interface modules and ensure communication to control systems is stable

• Regularly inspect terminal blocks for wear or oxidation

5. Optical Maintenance

• Schedule periodic cleaning of optical windows

• Inspect for scratches, cracks, or aging that can reduce signal quality

• Replace damaged windows immediately to prevent unreliable detection

• Avoid exposing the detectors to bright artificial lights during maintenance

6. Parameter Configuration

• Configure sensitivity based on the expected flame type (UV, IR, or combined)

• Set response time according to system safety requirements

• Follow ABB calibration and testing procedures during commissioning

• Document configuration changes to maintain consistent performance

7. Preventive Maintenance

• Conduct regular functional tests and log output signals

• Monitor detector trends for early identification of degradation

• Replace worn or aged components before failures occur

• Keep spare detectors on hand for critical systems

8. Engineering Boundaries and Unsuitable Applications

SF810INT detectors are not suitable for:

• Continuous analog flame measurement

• Extreme vibration or shock environments without reinforced mounting

• High electromagnetic interference zones without proper shielding

Understanding these limitations improves safety, reduces false alarms, and prevents system downtime.

9. Case Examples

Example 1: SF810INT-LOS-IR-NQ-C-W Misalignment

• Problem: Frequent flame loss alarms

• Diagnosis: Detector misaligned by 4 degrees

• Solution: Re-alignment restored stable signal

Example 2: SF810INT-LOS-UVIR-T-L Window Contamination

• Problem: Intermittent detection

• Diagnosis: Soot accumulation reducing UV/IR detection

• Solution: Cleaned window and implemented periodic cleaning schedule

Example 3: SF810INT-LOS-IR-TL-L-C-W Electrical Interference

• Problem: Random false alarms

• Diagnosis: Nearby variable frequency drives causing EMI

• Solution: Added shielded cables and verified grounding

10. Summary

ABB SF810INT flame detectors are critical for reliable combustion monitoring in industrial systems. Proper installation, optical maintenance, electrical inspection, and sensitivity configuration ensure stable operation. Addressing common issues from an engineering perspective prevents false alarms, maintains system safety, and reduces unplanned downtime. Following preventive maintenance schedules and understanding operational boundaries are essential for long-term reliability.