3-Attachment B - Technical Specs.pdf

IFB 2000004211

Attachment B

TECHNICAL SPECIFICATIONS

SPECIFICATION REQUIREMENTS REPAIR ELECTRIC MOTORS AND PUMPS

PART 1 - GENERAL REQUIREMENTS:

1. The Contractor shall be responsible for uninstalling, repairing, overhauling, installing, and reconnecting motors and pumps to the plumbing and electrical connections.

2. The Contractor must utilize highly skilled technical staff to perform high quality diagnosis, repair, and/or overhaul of a motor and pump, and to return it to good operating condition with a minimum of delay and cost.

3. The Contractor shall execute all the repair works in accordance with the manufacturer’s specifications and in accordance with the following codes and regulations:

• ANSI/EASA Standard AR100-2020: Recommended Practice for The Repair of Rotating Electrical Apparatus

• IEEE Std. 43 Recommended Practice for Testing Insulation Resistance of Electric Machinery.

• IEEE Std. 112, IEEE Standard Test Procedure for Polyphase Induction Motors and Generators

• ISO 21940-11:2016:/Amd 1:2022 Mechanical Vibration—Rotor balancing — Part 11:

Procedures and tolerances for rotors with rigid behavior

• NEMA Std. MG-1: Motors and Generators

• ABMA ANSI/ABMA Std. 7: Shaft and Housing Fits for Metric Radial Ball and Roller Bearings

4. The Contractor shall perform initial inspection; the motor and pump shall be dismantled to the extent needed to either fully identify or repair the problem, or to do the specified overhaul. The Contractor shall notify the Owner in writing with the scope of work and with a budgetary quote prior to execution of the repairs. No work shall be executed without the Owner’s approval prior to execution of the repairs.

5. Contractor shall notify the Owner whenever any damage is found which cannot be fully repaired or any indications for a permanent degradation of efficiency of any other performance parameters. The Owner’s approval is required prior to proceeding with the repairs.

6. After the repair is completed, the Contractor shall notify the Owner of all the work progress that has been done, problems noted, checks, tests and measurements taken during the work.

7. Upon receipt of the repaired motor and/or pump, the Owner will perform visual inspections to the repaired motor and/or pumps; the Owner shall notify the Contractor in case defects are noticed, prior to acceptance of the motor and/or pump.

8. The Contractor shall install the repaired motor and pump as part of the repair scope of work. Installation fees shall be in accordance with the On-Site Labor on the Pricing Schedule, included as a part of the quote, and approved by the Owner prior to repair.

9. The Contractor shall perform an insulation resistance test to ground, at a voltage suitable for the motor’s and pump’s voltage rating and the apparent condition of the motor and pump.

10. The Contractor shall run the repaired electric motor and pump to check for the nameplate voltage, balanced currents and vibration.

11. The Contractor is responsible for storing electric motors and pump’s bolts and all dismantled parts in dedicated containers.

12. The Contractor shall keep records of all tests and inspections carried out during the work. Signed copies of these records shall be shipped in original form, at the same time as the motor and/or pump, to the designated contact person.

13. The Owner shall always have access to the repair facilities that work is being done, for the purposes of checking progress and inspection of work.

14. The Owner shall be informed when the final inspection and testing of the motor and pump is to take place. Owner shall have the right to be present for tests on any motors and/or pumps. In emergency cases, test will not be held up waiting for Owner representatives, but every effort shall be made to keep Owner informed so they can be present if possible. All final inspection and test results shall be sent, in their original form, to the designated contact person.

PART 2 – TECHICAL SPECIFICATIONS OF CONTRACTOR:

1. Ensure that horizontal motors and/or pumps where the shaft rotor assembly is too heavy to be removed easily by hand, one or two cranes shall be used to move the shaft, with a close fitting pipe installed over one end of the shaft to act as a shaft extension. Attention shall be paid to the following:

• Slings shall not damage the bearing surfaces or the rotor

• Under no circumstances shall the stator windings be touched by any of the parts being moved

2. Dismantle the vertical motors and/or pumps in accordance to the manufacturer’s manuals. The assembly of vertical motors and/or pumps is critical. Particular attention shall be paid to, and records kept of:

• The amount of rotor lift

• The make and types of bearings, particularly the thrust bearings including orientation of thrust bearings

• The arrangement of the thrust and guide bearings, including specially ground mating surfaces

• The axial and radial clearances (fit) to the shaft and housing

• The method of lubrication of both upper and lower bearings

• The method of bearing insulation

• Any other particular features of the motor and/or pump configuration.

3. Whenever an electric motor and/or pump are rewound, the core shall be stripped, cleaned, tested and repaired.

4. Record all work progress, starting from the inspection to completion of the work. Recorded data shall include but not be limited to winding data to permit replicating original configuration.

5. Test core on all stators both before and after stripping and iron repairing in accordance with the manufacturer manuals.

6. Ensure that the winding will be burned out in a controlled temperature burnout oven where the part temperature is limited by means of fuel control and in accordance with the manufacturer’s specifications to ensure that the core iron can safely withstand the temperature.

7. Notify the Owner of all obvious iron damage, plus any problems indicated by the core loss tests, and significant frame damage, shall be reported to the Owner before proceeding further, and the Contractor shall discuss with the Owner the methods of repair to damaged cores and shall be chosen from the following:

• Grinding. Selective grinding with a small sharp power tool.

• Spray between laminates. Separating laminations and reinsulating with spray-on inter laminar insulation.

• Mica between laminations. Inserting split mica between the laminations.

• Restacking. Restacking, with de-burred laminations and new inter-laminar insulation.

8. Ensure that the total cross-sectional area of a turn, number of the turns per coil, the span and connection of the coils shall be in accordance with the manufacturer’s specifications and shall not be changed without authorization from the Owner.

9. Utilize Class F or higher system materials throughout. Windings that were originally Class H shall be replaced with a Class H rewind.

10. Temperature sensing devices shall be replaced, if needed, with devices comparable to those previously used.

11. Ensure that the end turns shall be fully compacted so that there are no loose wires. Both sets of end turn, plus leads and jumpers, shall be fastened tightly together so that each coil is tied securely to the two adjacent coils.

12. Ensure that all materials used for connections are corrosion free to resist the harsh operating environment.

13. Perform the winding tests to verify that there are no wrong connections or shorted turns before impregnation. This testing should include a surge comparison test, a high potential test, and winding resistance test. Voltage used shall be as indicated in EASA Recommended Practices for the Repair of Rotating Electrical Apparatus or other standards approved by Owner. Any defects shall be corrected and retested before impregnating. Test results shall be recorded in the Repairer’s Tracking Form.

14. Ensure that the rewound stator shall be impregnated in one of the following ways:

• Dip-and-Bake: Double dip-and-bake cycle using resin or varnish and a temperature-controlled bake oven (baking times and temperatures shall be recorded in the Repairer’s Tracking Form.)

• Trickle: A trickle epoxy or polyester treatment where the resin is poured into the end turns and slots of a vertically inclined stator, which has been heated with controlled electric current to assist in curing the resin.

• VPI: Vacuum Pressure Impregnation (VPI) treatment.

15. Routine overhauls shall include the following:

a. Dismantling and Testing: After dismantling, the following procedure shall be followed:

• Winding and cooling ducts shall be cleaned, dried and inspected

• Winding insulation resistance shall be tested in accordance with manufacturer’s specifications

• Cleaning: The components, including the stator windings, shall be cleaned in accordance with the manufacturer’s specifications.

• Drying- coils and insulation: All components shall be thoroughly dried at a temperature in accordance with the manufacturer’s specifications.

b. Repairs and Reassembly: Ensure that all repairs are performed in accordance with the manufacturer’s specifications and all applicable regulations and standards. All parts utilized in the overhaul repairs must be in good condition.

• Testing: All stators and rotors shall be tested for damaged bars, whether the motor and/or pump is suspect in this area or not. In case any damage is found to the stator and/or rotor, repairs shall be in accordance with the manufacturer’s specifications.

• Cage Repair and Replacements: Motor Cage shall not be repaired or replaced without prior authorization from the Owner.

• Balance: After the rotors are repaired in accordance with the manufacturer’s specifications, the rotor shall be dynamically balanced to the tolerances in accordance with the manufacturer’s specifications.

16. SHAFT REPAIR:

a. General: The shaft utilized in the repaired motor and/or pump shall be straight, parallel, tight fit to the rotor iron and undamaged at the bearing areas and without any cracks. If a shaft has a problem, it shall be tested and repaired or replaced. If there is any risk or uncertainty in the proposed repair method, this shall be discussed with the Owner prior to proceeding. Replaced shafts shall be fabricated in accordance with the manufacturer’s specifications. Shaft extension dimension tolerances shall be within the limits specified in NEMA MG-1, Motors and Generators sections.

17. ANTI-FRICTION BEARINGS:

a. New Bearings: Anti-friction bearings shall always be replaced. New bearings shall be of the manufacturer recommended types, unless otherwise approved by the Owner. If the bearing type, size, sealing, shielding or configuration is changed, this shall be noted on a supplemental nameplate. If the original bearing race showed pitting from shaft current, the causes and remedy for this shall be discussed with Owner.

b. Shielding, Sealing: If the method of shielding, sealing or lubricating is to be changed, it shall be approved by the Owner.

c. Clearance: Unless otherwise specified by the manufacturer, C3 clearance bearings shall be used for all bearings.

d. Tolerances: Fitting tolerances to the journals and housings shall be per manufacturer’s specifications. Out of tolerance fits shall be restored in accordance with ANSI/ABMA regulations.

e. Heating: The bearing shall be heated and installed in accordance with the manufacturer’s specifications.

f. Grease: Greaseable bearings shall be lubricated as specified in the EASA Recommended Practice for the Repair of Rotating Electrical Apparatus or other standards approved by the Owner.

Lubrication shall be in accordance with the motor and/or pump manufacturer’s specifications.

g. Insulated Bearings: Insulated bearing resistance shall be in accordance with the manufacturer and/or IEEE regulations.

18. END BRACKETS:

a. Requirements: End brackets shall fit snugly to the stator frame. Tolerances shall be in accordance with the manufacturer’s specifications.

b. Repairs: Repairs to end bracket bearing housings shall be accomplished by building up the metal and machining to size. Welding, plating and sleeving are the accepted methods. Epoxies and other compounds shall not be used for locking bearings.

19. OTHER DEVICES:

a. Fans:

• Fans shall be checked for cracks and fit to the shaft and/or rotor and shall be firmly fixed to the shaft or rotor by the original factory method.

• Fans shall not be repaired unless the Owner agreed.

• If the fan is not repaired, new fans shall be supplied by the original manufacturer or equal.

• Fans used in motors for use in hazardous locations shall be made of material that will not cause sparking, either by impact or by buildup of static electricity.

b. Temperature Sensors: Temperature sensors shall be installed in the motor as originally found or as otherwise agreed by the Owner.

• Bearing: Bearing sensors shall be of the same type as those removed and shall be located to sense, as nearly as possible, the highest bearing temperature. If the original bearing sensor was insulated, the replacement shall also be insulated.

• Winding: Sensor type shall be the same as the original and will usually be located in the end turns.

c. Leads: Leads shall be flexible and multistranded and have at least the same cross-sectional area as the original leads. Temperature class must be the same as original or better. Main power and accessory leads shall be indelibly marked using the same marking systems as the incoming motor.

If this is illegible, then the system described in NEMA MG-1, Motors and Generators shall be used.

Every effort shall be made to keep the original direction of rotation. Lugs, if used, shall be suited for the application and have all cable strands in the lug. No cable strands may be cut off or bent back to facilitate insertion in the lug. If crimp lugs are used, the correct make and style of die shall be used for the particular lug, and the correct compression applied.

d. Terminal Boxes: Terminal boxes shall be returned to original condition. In particular, the following items must be confirmed.

• Missing bolts and gaskets for both the cover and the motor-to-box joint shall be replaced.

• On motors certified for hazardous environments, the junction boxes shall be sealed off from the main body of the motor by a sealing compound approved by UL for this application.

• Damaged flanges shall be repaired. No paint or gaskets shall be left on the flanges of boxes for explosion-proof motors.

e. Space Heaters: Space heaters shall be tested for insulation resistance for one minute according to manufacturer’s specifications. They shall be tested for correct functioning.

f. Vibration Sensors: Vibration sensors shall be replaced in their original locations.

g. Balancing: The motor rotor shall be dynamically balanced in a balance stand before assembly of the motor. Balance criteria shall be in accordance with the manufacturer’s specifications.

20. REASSEMBLY: Ensure that the motor reassembly is the reverse of the disassembly process and in accordance with the manufacturer manuals.

21. FINAL TESTS:

a. Insulation: Prior to running, an insulation resistance test to ground shall be performed. After the insulation tests, the motor and/or pump shall be run at no load at full terminal voltage, with either a half key or a half coupling, on the shaft. If the motor and/or pump use an external oil supply and removal system in normal use, a similar system shall be arranged for the test. The test shall determine that:

• No Load Amps: No load current unbalance at balanced rated voltage shall be less than 2 percent.

• Vibration: Horizontal, vertical and axial readings shall be taken at each bearing and results recorded. Tolerance shall not exceed EASA Recommended and the manufacturer’s specifications

• Temperature Rise: Temperature rise after levels stabilize shall be within normal limits on the frame and bearings.

• Shipment: At the completion of the test, the motor shall be painted as in accordance with the manufacturer’s specifications and prepared for shipment. Any lubricant and coolant inlets and outlets shall be plugged and masked before painting and shipping. Any special precautions or preparations that should be noted before powering the motor shall be indicated on a tag.

22. OTHER MATERIALS

a. Anti-Friction Bearings: Anti-friction bearings shall be replaced, if needed, in accordance with the manufacturer’s specifications.

b. Solid Insulation: Insulating materials such as slot liners, tapes and phase insulation shall meet or exceed the temperature class of the motor and shall be compatible with the resins used.

Specifications for the materials shall be obtained from the material supplier and kept for checking their suitability for the application. The materials shall be stored in a clean, dry location. Material such as B stage tape that degrades with time at room temperature shall be kept refrigerated.

c. Other Materials: Ensure that all replaced parts are new and of good quality. In particular, the following shall be confirmed:

• Lead Wires: Lead wires shall be multi-stranded and flexible with insulation meeting or exceeding the temperature and voltage class of the motor.

• Magnet Wire: Magnet wire for random-wound motors shall be compatible with the other insulation system components and shall be insulated with a polyamide, polyimide or a combination of both, over a polyester base coat, or equivalent. Any wire damaged in storage or working shall be replaced. The manufacturer’s specifications for the insulation shall be kept on file for reference. Inverter grade wire shall be used on any motor and/or pump that Owner advises is powered by a pulse-width modulated inverter.

PART 3 – SHIPPING AND WARRANTY:

1. Provide 72 hours’ notice prior to delivery of material back to County sites.

2. All work and parts provided under this contract shall have, as a minimum, a one-year warranty from the date of final acceptance thereof against the latent defects, designs, materials, workmanship, installation, fraud, or such gross mistakes, as may amount to fraud. Copies of warranties shall be submitted to the Owner after completion of work.

3. When defective work and/or materials are found during the warranty period, the Owner shall notify the contractor, in writing, and the contractor shall respond within seven (7) days of the notification. Upon receipt of notice from the County, or failure of any item or appurtenance thereto and signs of deterioration during the warranty period, the contractor shall, at his own expense, promptly adjust or repair of furnish and install necessary replacement parts or design, workmanship, material approved by the County or replace the complete item.