15-Specification Section 40 05 93.Mechanical Integration of Existing Pumps and New Motors. Addendum No.2.pdf

Great Lakes Water Authority (GLWA) February 2025 GLWA - TOES VFD Replacement Issue for Bid

MECHANICAL INTEGRATION OF EXISTING PUMPS AND NEW MOTORS

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SECTION 40 05 93

INTEGRATION OF EXISTING PUMPS WITH NEW MOTORS AND DRIVES

PART 1 - GENERAL

1.1 SCOPE OF WORK

A. The Work of this Section shall include all labor, materials, equipment, and incidentals necessary to evaluate, design and install new and refurbished and redesigned pump motors controlled by variable frequency drives (VFDs) on the existing vertical solids handling pumps.

B. One new 1000 hp medium-voltage induction motor shall be furnished and five (5) existing 900hp synchronous motors shall be refurbished and rewound to 1000hp medium-voltage induction motors in accordance with Section 26 60 20. The Contractor shall have unit responsibility for mechanical integration of the new motor and rewound motors and the new VFDs with the existing Worthington pumps.

C. The phasing and sequencing of the Work is required to limit the impact of taking pumps out of service. Not more than one (1) pump shall be removed from service at one time. The sequence and progress of the Work shall follow the requirements of paragraph 1.5 of Section 01 11 00.

D. The Contractor shall coordinate the selection of VFDs specified under Section 26 based on test results of the new and refurbished motors. The new motors are anticipated to draw a maximum 140 A continuously at full load. The rewound motors are anticipated to draw a maximum of 140 A continuously at full load. The Contractor shall ensure new and rewound motors are tested and continuous current at full load for each are below the maximum design amount for the VFDs prior to releasing the VFDs for manufacture.

E. The professional services of a dynamic analysis specialist shall be retained to perform a finite element dynamic analysis of the complete integrated pumping machinery, as specified herein.

Following the analysis, the Contractor shall determine the necessary mechanical modifications in the power transmission system before installation the new or rewound motors having a higher horsepower rating. Mechanical modifications could include, but are not limited to, replacement of drive shafts, couplings and fasteners or adjustments to motor mass, as required to mitigate issues related to torque, vibration or any natural resonant frequencies of the modified pump system and pump station.

F. Costs associated with the required mechanical modifications shall be covered by Allowance.

Contractor shall obtain pricing to provide all materials, labor and equipment for identified mechanical modifications and submit a detailed and itemized proposal to the Owner for review.

Upon Owners’ review and written acceptance of a proposal, Contractor shall proceed with work and submit for payment under the allowance in accordance with the requirements of the Contract.

1.2 RELATED WORK

A. Required sequence of construction is included in Section 01 11 00.

B. Allowances are described in Section 01 21 00.

C. Material and finish requirements of fasteners used in mechanical integration shall be in accordance with Section 05 43 00.

D. Medium voltage motors are included in Section 26 60 20.

E. Adjustable speed drives with variable frequency controllers are included in Section 26 19 13.

1.3 REFERENCE STANDARDS

A. Hydraulic Institute (HI) Standards:

MECHANICAL INTEGRATION OF EXISTING PUMPS AND NEW MOTORS

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1. HI 9.6.4 – American National Standard for Rotodynamic Pumps – Centrifugal and Vertical Pumps – Vibration Measurements and Allowable Values.

2. HI 9.6.8 – American National Standard for Rotodynamic Pumps – Guidelines for Dynamics of Pumping Machinery

B. Where reference is made to one of the above standards, the revision in effect at the time of bid opening shall apply.

1.4 SUBMITTALS

A. Submit the following in accordance with Section 01 33 00:

1. Pre-construction vibration field testing and analysis report.

2. Dynamic vibration analysis report, including backup documentation and certified statement that the analysis as required in Paragraphs 1.07 and 1.08 of this Section have been completed and that the specified limitations will be met.

3. Field testing report, including data collection instrument calibration certification, tabulated data collected during testing, testing personnel present, and comparison of testing data to the requirements herein.

B. Submit motor test data for new and rewound motors and evidence of coordination and confirmation of VFD sizing with Rockwell.

C. Submit detailed and itemized proposal for mechanical modifications to pump drive system identified by dynamic analysis.

1.5 VIBRATION ANALYSES

A. Retain the professional services to perform the vibration analyses and field work related to the analyses specified herein of the existing finished water pumps and the new or rewound motors supplied under Section 26 60 20. Vibration analyses shall be performed by one of the following:

1. Mechanical Solutions Inc. (MSI), Whippany, NJ.

B. The provider of vibration analyses shall perform pre-construction field testing and analysis, prepare a pre-construction testing and analysis report, perform dynamic vibration analyses, and prepare a dynamic vibration analysis report.

C. The maximum vibration velocity in inches per second RMS shall meet the requirements of HI 9.6.4.

1.6 PRE-CONSTRUCTION VIBRATION FIELD TESTING AND ANALYSIS

A. Perform pre-construction field testing of the existing foundation, piping, nearby building floor, and existing pumps and motors to determine structural and torsional rotodynamic natural frequencies and their separation margins from excitation sources. Structural analysis excitation sources include running speed, 2x running speed, and vane pass within the intended operating speed range. The torsional rotordynamic natural frequencies are the same plus 1x and 2x line frequency and 6x and 12x VFD control frequencies. The testing will consist of experimental modal analysis (impact testing) and operating deflection shape (ODS) testing. Impact testing shall be conducted under single pump operation and multiple pump operation using the time averaged pulse (TAP™) methodology. Strain gages with telemetry shall be used to measure the torque and torsional rotordynamic natural frequencies of the pump rotor-intermediate shaft-motor rotor rotating system. Field measurements needed for the follow analysis work will be collected during the testing trip.

B. Prepare a detailed Finite Element Analysis (FEA) model of the pump support system (defined as a portion of the building floor, foundation, piping out to the first pipe supports or expansion joints) shall be constructed. The existing pumps, intermediate shafts, and motors will be represented in the structural system model as cylinders with the correct mass, center of gravity, and inertia and hold-on down bolt locations based on available information for the existing pumps and motors. The torsional rotordynamic system model will be constructed using estimates for the rotating systems mass, inertia , and center of gravity for the existing machinery.

MECHANICAL INTEGRATION OF EXISTING PUMPS AND NEW MOTORS

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The assembled models shall be iterated until there is sufficient agreement between the modeled structural and torsional rotordynamic system natural frequencies and the measured natural frequencies.

C. Prepare and submit a pre-construction testing and analysis report, including the following:

D. Testing personnel and qualifications.

E. Testing equipment, including calibration records of measurement devices.

F. Submit a testing report that includes a sketch of the unit indicating where and in which direction the vibration readings were taken and recorded showing (a) peak to peak displacement, in mils,

(b) frequency spectrum and (c) velocity level, in inches per second rms. The report shall contain a complete analysis of findings, describing any problems encountered, if any, probable cause and specific recommendations for any required corrective action. Plots and animations showing system natural frequencies and torsional natural frequencies and their separation margins from excitation sources. The report will include Campbell Diagrams noting separation margins and Frequency Response Function (FRF) plots from the impact tests for potentially resonant natural frequencies.

1.7 DYNAMIC VIBRATION ANALYSES

A. The purpose of the analyses is to ensure that the new and rewound motors will operate with the existing pumps without structural resonance and torsional rotodynamic problems throughout the assumed pump rotational speed range of 50%-100% maximum rotational speed.

B. The following minimum separation margins shall be used:

1. Structural Analysis: The predicted natural frequency of the new or rewound motors and existing pumps shall be a minimum of 15% above the maximum rotational speed or a minimum of 15% below the minimum pump rotational speed.

2. Torsional Rotodynamic Critical Speeds will be +/-10% from 1x and 2x pump running speed, vane pass, 1x and 2x electrical line frequencies as well as 6x and 12x VFD control frequency excitations within the intended speed range.

C. Perform a structural analysis using the pump system FEA model established per Paragraph 1.6.B. The FEA model will have the representative models of the existing pump and motor replaced with a detailed model of the new or rewound motor mounted on the existing motor supports including the nearby floor. Any new pump system support features will also be added to the FEA model.

D. Perform structural analysis iterations if the initial structural analysis indicates that the separation margin criteria are not met creating potentially harmful natural frequencies. In this case, the structural analysis should attempt to modify the structure and iterate the design and analysis until the separation margin criteria are met. If changes to the geometry cannot satisfy the separation margin criteria , a forced response analysis will be performed to predict operational vibration levels, which must not exceed the vibration limits specified herein.

E. Perform a torsional rotodynamic critical speed analysis of the motor rotor-intermediate shafting-pump rotor system using the new or rewound motor’s dynamic characteristics to ensure that torsional rotodynamic critical speeds meet the specified separation margin criteria.

F. Perform torsional rotodynamic critical speed analysis iterations, if the initial analysis indicates that the separation margin criteria are not met. In this case, the torsional rotodynamic critical speed analysis shall modify the rotor system and iterate the design and analysis until the separation margin criteria is met. Alternately, a forced response analysis will be performed to predict if the pump can operate safely on or near a potential harmful torsional natural frequency by determining the mean and alternating stresses (with stress concentration factors) in the rotating elements of the pump by plotting these stresses on a Goodman Diagram with a factor of safety against fatigue failure of at least 2.

MECHANICAL INTEGRATION OF EXISTING PUMPS AND NEW MOTORS

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G. Submit a dynamic vibration analysis report, including executive summary with conclusions and recommendations, description of analysis process, backup of data or values used in analysis, frequency tables and Campbell Diagrams for the structural analysis and torsional rotodynamic analysis showing separation margins versus typical excitation frequencies, conclusions comparing the analysis results to the requirements of this Section, resume of lead analyst, and signature of signed analyst that the analysis was conducted and the report prepared under his/her supervision

PART 2 - PRODUCTS

2.1 POWER TRANSMISSION COMPONENTS

A. Should pump power transmission components require redesign and/or replacement the new system shall be compiled in the same configuration as the existing system. Fasteners used by the Contractor shall meet the material and finish requirements in Section 05 43 00

B. Disc Couplings and Universal Drive Shafts, Johnson Power LTD, Broadview, Illinois

C. Steady Bearings, Rexnord Corporation, Waukesha, Wisconsin

PART 3 - EXECUTION

3.1 MOTOR INSTALLATION

A. Install the motors per manufacturer’s installation instructions:

1. Prepare rigid foundation or mounting surface to minimize vibration and maintain alignment between motor and load shaft.

2. Align the motor shaft with driven equipment according to manufacturer’s written instructions. Adjust axial position of motor frame with respect to load shaft.

3. Accurately adjust flexible couplings for direct drive according to machine manufacturers’ guidelines. Check alignment to minimize vibrations. Coupling spacing shall be according to coupling manufacturer guidelines.

4. Anchor motor base to load bearing surface with grade 5 steel bolts or better.

B. Pre-commissioning Inspection:

1. Inspect for physical damage. Verify all shipping materials and braces are removed.

2. Inspect for proper mounting. Verify that the motor and the coupled load are properly aligned. Inspect bearings for proper lubrication and rotate motor shaft by hand to check for binding. Oil lubricated bearing housings that have been filled with preservative oil shall be drained and re-filled with proper grade of bearing oil before putting the machine into service. Check all hardware for looseness and re-tighten as necessary.

3. Clean motor externally, on completion of installation. Vacuum dirt and debris; do not use blown compressed air to assist in cleaning.

3.2 PUMP TESTING

A. After installation and as soon as conditions permit full speed operation, the vibration analyses services provider shall perform a detailed vibration test of each pumping unit, including both Experimental Modal Analysis (impact) and X-Y vibration profiles, to (a) prove compliance with the specified vibration limitations and (b) prove there are no field installed resonant conditions due to misalignment, the foundation, or the connecting piping and its supports, when operating at any speed within the specified operating range.

B. Testing shall occur at the design full speed, design minimum speed, and at a maximum of 3 Hz increments between minimum and full speed. Submit a testing report that includes a sketch of the unit indicating where and in which direction the vibration readings were taken and recorded showing (a) peak to peak displacement, in mils, (b) frequency spectrum and (c) velocity level, in inches per second rms. The report shall contain a complete analysis of findings, describing any

MECHANICAL INTEGRATION OF EXISTING PUMPS AND NEW MOTORS

40 05 93 - 5 problems encountered, if any, probable cause and specific recommendations for any required corrective action.

C. If required, the Contractor shall take corrective action and have the units retested to ensure full compliance with the specified requirements. All costs associated with the field tests or any required corrective action shall be borne by the Contractor.

D. Complete field vibration testing on all pumping units as described herein 6 months after signature testing. Submit a report that compares the results of the 6 month tests with the results of the signature tests. If in the judgment of the Engineer there is a significant increase of the overall vibration level, the Contractor shall determine the cause and implement corrective action and retesting to verify reduction in vibration.

E. After operation within vibration limits are confirmed, operate each pump for 24 continuous hours. Measure and record motor amps, operating speed, flow rate, and vibration and temperature from the Ovation machine health monitoring system specified in Section 26 60 20.

Submit collected data for the Engineer’s assessment that the integrated pump and motor are operating within expected ranges.

F. Pumping test specified herein shall be completed in accordance with sequencing of Section 01 75 11 Checkout and Startup Procedures.

END OF SECTION

B. Where reference is made to one of the above standards, the revision in effect at the time of bid opening shall apply.