Pioneer in Intelligent O&M for Metro Environmental Control Systems

1. Equipment Information

Equipment Type: Pump

Rated speed: 1465rpm

Measuring point associated with this case: Motor load end 2H

2. Alarm and Analysis Process

2022-07-10 07:15, a secondary alarm occurred at the motor load end 2H.

2.1 Analysis Process

2.1.1 Evidence Description of Trends, Index Parameters, etc.

The speed trend of the motor and pump end is slowly increasing.

Zhenning Road - Cooling Water Pump LQ-A1/Motor Load End 2H/16k Speed Waveform (2-1000)_Equipment Multi-Trend

The low-frequency trend at the motor load end is also slowly increasing.

Zhenning Road - Cooling Water Pump LQ-A1/Motor Load End 2H/128k Acceleration Waveform (0.1-2000)_Trend Analysis

2.1.2 Time domain, spectrum, envelope demodulation and other evidence indicate

The velocity waveform is close to a sinusoidal shape.

Zhenning Road - Cooling Water Pump LQ-A1 / Motor Load End 2H / 16k Velocity Waveform (2-1000)_Time Domain Waveform

The velocity spectrum is mainly dominated by rotational frequency energy, accompanied by a small amount of harmonics.

Zhenning Road - Cooling Water Pump LQ-A1 / Motor Load End 2H / 16k Velocity Waveform (2-1000)_Spectrum Analysis

3. Diagnostic Conclusions and Recommendations

3.1 Diagnostic Conclusions

2022-07-10 14:37 Pushed diagnostic conclusion: The unit's vibration is slowly increasing, speculated to be related to insufficient foundation stiffness or the operating status of the coupling, slowly deteriorating.

3.2 Inspection and Maintenance Recommendations

The equipment is currently in a monitorable operating state. It is recommended to arrange an inspection when appropriate. Patrol inspections should focus on changes in motor and pump-end vibration and abnormal coupling operation noise, and check whether the foundation connection bolts are loose.

4. On-site Inspection and Maintenance Process

2022-08-16 09:43 Rongzhi Diagnosis engineer reminded the site to pay attention again. 

2022-08-17 17:04 Tracked the on-site feedback and overhauled and replaced the coupling elastic gasket.

5. On-site inspection and maintenance photos

Coupling gasket is worn and broken.

Coupling gasket wear fracture_1

6. Verification after inspection and maintenance

After the on-site repair of the coupling, the total speed value of each measuring point of the unit dropped significantly.

Zhenning Road - Cooling Water Pump LQ-A1/Motor Load End 2H/128k Acceleration Waveform (0.1-2000)_Equipment Multi-Trend

The amplitude of the velocity waveform decreases significantly.

Zhenning Road - Cooling Water Pump LQ-A1/Motor Load End 2H/128k Acceleration Waveform (0.1-2000)_Time Domain Waveform

The speed spectrum 1X frequency energy decreased significantly.

Zhenning Road - Cooling Water Pump LQ-A1 / Motor Load End 2H / 128k Acceleration Waveform (0.1-2000) _ Spectrum Analysis

7. Customer Feedback Form

None

8. Monitoring Fault Range

The timely and effective collection of equipment operating status data (vibration, temperature) is subject to network smoothness and data transmission time, and also needs to consider the interference of equipment attributes, production technology and other factors. At the same time, the analysis and diagnosis of equipment status is based on the change of vibration effect caused by the failure of rotating moving parts. Therefore, the condition monitoring system cannot guarantee to monitor all types of faults. The monitoring system is configured according to the measuring point scheme recommended by Party B, and the monitoring fault range and description are as follows:

9. Precautions

If the client of this report cannot provide basic unit parameters (such as: unit transmission chain diagram, gearbox structure diagram, number of gearbox teeth, related bearing models and brands), it will affect the accuracy of the analysis and diagnosis.

This report contains analyses, diagnoses, and maintenance recommendations for the unit provided by Roteon's professional technical personnel. It is for reference only, and the client should make its own decisions regarding specific maintenance and repair measures.

This report shall not be used as evidence for any claims, lawsuits, or other legal proceedings.

The client is obligated to keep the analysis report confidential and shall not provide this report to any third party, print it into other promotional materials, or publish it on public information platforms such as the internet without the written permission of the trustee.

1. Equipment Information

Equipment Type: Pump

Rated speed: 1465rpm

Measuring point associated with this case: Motor Load End 2H

2. Alarm and Analysis Process

Equipment alarm event:

2.1 Analysis Process

2.1.1 Description of Evidence such as Trends and Index Parameters

Recently, the speed vibration of all measuring points of the unit has been continuously increasing, and the speed vibration amplitude is high.

Jianshe Yi Road - Chilled Water Pump LD-A2 / Pump Load End 3H_Equipment Multi-Trend

2.1.2 Description of Evidence such as Time Domain, Spectrum, and Envelope Demodulation

The speed time-domain waveform is similar to a sine wave.

Jianshe Yi Road - Chilled Water Pump LD-A2 / Pump Load End 3H_Time Domain Waveform

The spectrum mainly shows an increase in 1X rotational frequency energy.

Jianshe First Road - Chilled Water Pump LD-A2 / Pump Load End 3H_Spectrum Analysis

3. Diagnostic Conclusions and Recommendations

3.1 Diagnostic Conclusions

2022-10-02 07:59 Pushed diagnostic conclusion: The unit's speed vibration is increasing, which is speculated to be related to the abnormal coupling, and it has been continuously deteriorating recently.

3.2 Inspection and Maintenance Recommendations

The equipment is currently in a monitorable operating state. It is recommended to arrange an inspection when appropriate. Verify the unit's speed vibration, re-check the alignment of the coupling and the deformation and wear of the elastic components; simultaneously check whether the unit's foundation bolts are loose.

4. On-site Inspection and Maintenance Process

2022-10-09 17:22 On-site feedback indicates that the elastic pad of the coupling is worn.

5. On-site Inspection and Maintenance Photos

The maintenance photos show that the plum coupling pad of the coupling is deformed and broken.

Inspection Photo_1

6. Verification after Maintenance

The unit has not been started after the on-site maintenance, and the equipment status after maintenance cannot be evaluated.

Jianshe 1st Road - Chilled Water Pump LD-A2_Multi-Parameter Analysis

7. Customer Feedback Form

None

8. Monitored Fault Range

The timely and effective collection of equipment operating status data (vibration, temperature) is restricted by network smoothness and data transmission time, and the interference of equipment attributes and production processes should also be considered. At the same time, the analysis and diagnosis of equipment status are based on changes in the vibration effects caused by rotating moving parts failures. Therefore, the condition monitoring system cannot guarantee monitoring of all types of failures. This monitoring system is configured according to the measurement point scheme recommended by Party B. The monitored fault range and description are as follows:

9. Precautions

If the client of this report cannot provide basic unit parameters (such as unit transmission chain diagram, gearbox structure diagram, number of gearbox teeth, related bearing models and brands), it will affect the accuracy of the analysis and diagnosis.

This report is an analysis, diagnosis, and maintenance opinion of the unit by Rote knowledge professional technicians, and is for reference only. The specific maintenance measures need to be determined by the client.

This report shall not be used as any proof material for claims, lawsuits, etc.

The client is obliged to keep the analysis report confidential, and shall not provide this report to a third party, print it into other promotional materials, or publish it on the Internet or other public information platforms without the written permission of the trustee.

1. Equipment Information

Equipment Type: Centrifugal Fan

Rated speed: 990rpm

Associated measurement point in this case: Fan load end 3H

2. Alarm and Analysis Process

Equipment alarm event:

2.1 Analysis Process

2.1.1 Evidence Description of Trends, Indicator Parameters, etc.

The vibration of the unit continues to increase, with the increase at the fan load end being the most significant.

Jianshe Third Road - Fan K-A2/Motor Load End 2H/128k Acceleration Waveform (0.1-2000)_Multi-parameter Analysis

2.1.2 Evidence Description of Time Domain, Spectrum, Envelope Demodulation, etc.

No obvious impact is seen in the time domain waveform.

Jianshe Third Road - Fan K-A2/Fan Load End 3H/16k Velocity Waveform (2-1000)_Time Domain Waveform

Multiple spectra show a significant increase in 1X rotation frequency energy.

Jianshe 3rd Road - Fan K-A2 / Fan Load End 3H / 16k Velocity Waveform (2-1000)_Spectrum Analysis

3. Diagnosis and Recommendations

3.1 Diagnostic Conclusion

2023-04-02 00:03 Pushed diagnostic conclusion: The vibration at the fan load end is increasing, which is speculated to be related to belt wear or insufficient foundation stiffness, and is currently slowly deteriorating.

3.2 Maintenance Recommendations

The equipment is currently in a monitorable operating state. It is recommended to arrange an inspection when appropriate. Pay attention to changes in equipment vibration, check whether the anchor bolts are loose, and check whether the belt is worn when appropriate.

4. On-site Inspection and Maintenance Process

2023-04-11 16:36 On-site feedback indicates that the belt has been replaced. The belt was worn, and the vibration decreased significantly after replacement.

5. On-site Inspection and Maintenance Photos

The photo shows the belt is broken.

Maintenance Photo_1

6. Verification after Maintenance

After replacing the belt, the vibration at the fan's load end decreased significantly.

Jianshe Third Road - Fan K-A2/Motor Load End 2H/128k Acceleration Waveform (0.1-2000)_Multi-parameter Analysis

Multiple spectra show a significant drop in the rotational frequency and its harmonic energy.

Jianshe 3rd Road - Fan K-A2 / Fan Load End 3H / 16k Velocity Waveform (2-1000)_Spectrum Analysis

7. Customer Feedback Form

None

Feedback Form_1

8. Monitoring Fault Range

The timely and effective collection of equipment operating status data (vibration, temperature) is subject to network smoothness and data transmission time, and also needs to consider the interference of equipment attributes, production technology, and other factors. At the same time, the analysis and diagnosis of equipment status are based on changes in the vibration effects caused by rotating moving parts failures. Therefore, the condition monitoring system cannot guarantee monitoring of all types of failures. This monitoring system is configured according to the measurement point scheme recommended by Party B, and the monitorable fault range and description are as follows:

9. Precautions

If the client of this report cannot provide basic unit parameters (such as: unit transmission chain diagram, gearbox structure diagram, gearbox gear number, related bearing models and brands), it will affect the accuracy of the analysis and diagnosis.

This report is the analysis, diagnosis, and maintenance advice of the unit by Richeng's professional technicians, and is for reference only. The specific maintenance measures still need to be determined by the client.

This report is not to be used as proof for any claims, lawsuits, etc.

The client is obliged to keep the analysis report confidential and shall not provide this report to a third party, print it into other promotional materials, or publish it on public information platforms such as the Internet without the written permission of the trustee.

1. Equipment Information

Equipment Type: Centrifugal Fan

Rated Speed: Variable Frequency Equipment

Measuring point associated with this case: Motor Load End 2H

2. Alarm and Analysis Process

Equipment Alarm Event:

2.1 Analysis Process

2.1.1 Evidence Description of Trends, Index Parameters, etc.

The vibration of each measuring point of the unit increased significantly, and the maximum value at the motor load end reached about 18mm/s.

Jianshe Third Road - Fan K-A1/Motor Load End 2H/16k Velocity Waveform (2-1000)_Multi-parameter Analysis

2.1.2 Evidence Description of Time Domain, Spectrum, Envelope Demodulation, etc.

There are obvious periodic disturbances in the velocity time domain waveform.

Jianshe Third Road - Fan K-A1/Motor Load End 2H/16k Velocity Waveform (2-1000)_Time Domain Waveform

The spectrum is mainly composed of 9.766Hz and its rich harmonics.

Jianshe 3rd Road - Fan K-A1 / Motor Load End 2H / 16k Velocity Waveform (2-1000) _ Spectrum Analysis

3. Diagnosis and Recommendations

3.1 Diagnosis

Diagnostic conclusion pushed at 16:38 on 2023-08-26: The speed vibration at the motor load end has increased significantly, which should be related to the abnormal running state of the belt, indicating significant deterioration.

3.2 Inspection and Maintenance Recommendations

The equipment is currently in a monitorable operating state. It is recommended to arrange an inspection when appropriate. It is recommended to check whether the running status of the belt is good, whether there is severe wear or breakage, and also check for insufficient tension in the belt.

4. On-site Inspection and Maintenance Process

2023-08-30 10:42 On-site feedback indicates that belt wear has led to belt cracking.

5. On-site Inspection and Maintenance Photos

It can be seen from the overhaul photos that one of the belts is broken, and the remaining belts are severely worn and fatigued.

Maintenance Photo_1

6. Verification after Maintenance

After handling the belt, the speed vibration decreased significantly, and the speed vibration trend was consistent with the original vibration magnitude.

Speed Vibration Trend at the Motor Drive End

The disturbance phenomenon in the speed time-domain waveform is significantly weakened, and the disturbance amplitude decreases significantly.

Comparison of Speed Time-Domain Waveforms at the Motor Drive End Before and After Treatment

The energy of the belt passing frequency in the spectrum is significantly reduced.

Comparison of Speed Spectrum at the Motor Drive End Before and After Treatment

7. Customer Feedback Form

Feedback Form_1

8. Monitoring Fault Range

The timely and effective acquisition of equipment operating status data (vibration, temperature) is constrained by network smoothness and data transmission time, and also needs to consider interference from factors such as the equipment's own attributes and production processes. At the same time, the analysis and diagnosis of equipment status are based on changes in vibration effects caused by rotating moving parts failures. Therefore, the condition monitoring system cannot guarantee monitoring of all types of failures. The monitoring system is configured according to the measurement point scheme recommended by Party B, and the monitoring failure range and description are as follows:

9. Precautions

If the client of this report cannot provide basic unit parameters (such as unit transmission chain diagram, gearbox structure diagram, number of gearbox teeth, related bearing models and brands, etc.), it will affect the accuracy of the analysis and diagnosis.

This report is for the analysis, diagnosis, and maintenance suggestions of the unit by Ronly professional technicians, and is for reference only. The specific maintenance measures still need to be determined by the client.

This report is not to be used as any claim, litigation, or other proof materials.

The client is obliged to keep the analysis report confidential, and shall not provide this report to a third party, print it into other promotional materials, or publish it on the Internet or other public information platforms without the written permission of the trustee.