This article is about Medium Voltage Motor Storage, Handling, and Preservation Checklist, motor storage best practices, motor preservation for commercial buildings, plants and refinery projects as per international codes and standards.
Medium Voltage Motor Storage, Handling, and Preservation Checklist
Medium Voltage Motor Storage,
| QC Before Installation- Motors shall conform to all applicable requirements, standards, and specifications prior to release to be used as part of work. |
| Incoming motors shall be visually inspected for damage / defects occurred during transportation. |
| Motor shall be carefully inspected when the unit is received, inspect the carton for any sign of damage or tampering. NFPA 70 (NEC) Sec. 110.3 (B), Manufacturer’s Instruction. |
| Where possible, motors should be stored indoor in a clean dry area. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| When indoor storage is not possible, the motors must be covered with a tarpaulin. This cover should extend to the ground; however, it should not tightly wrap the motor. This will allow the captive air space to breathe, minimizing formation of condensation. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
Medium Voltage Handling
| Avoid severe jarring and / or dropping. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| Handle units with care to prevent damage to components or special finishes. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
Medium Voltage Motor Preservation
| Care must also be taken to protect the motor from flooding or from harmful chemical vapors. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| Whether indoors or out, the area of storage should be free from ambient vibration. Excessive vibration can cause bearing damage. A unit which must be stored in areas with high ambient vibration, such as from heavy construction equipment or other sources, must have the shaft locked to prevent any movement. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| Precaution should be taken to prevent rodents, snakes, birds, or other small animals from nesting inside the motors. In areas where they are prevalent, precautions must be taken to prevent insects, such as mud dauber wasps, from gaining access to the interior of the motor. NFPA 70 (NEC) Sec.110.3 (B) and Manufacturer’s Instruction. |
| Inspect the rust preventive coating on all external machined surfaces, including shaft extensions. If necessary, recoat the surfaces with a rust preventive material, such as Rust Veto No. 342 (manufactured by E.F. Houghton Co.) or equivalent. The condition of the coating should be checked periodically and surfaces recoated as needed. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| Grease lubricated cavities must be completely filled with lubricant during storage. Remove the drain plug and fill cavity with grease until grease begins to purge from drain opening. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| To prevent moisture accumulation, some form of heating must be utilized to prevent condensation. This heating should maintain the winding temperature at a minimum of 5ºC above ambient. If space heaters are supplied, they should be energized. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| If none are available, single phase or “trickle” heating may be utilized by energizing one phase of motor’s winding with a low voltage. A third option is to use an auxiliary heat source and keep the winding warm by either convection or blowing warm air into the motor. NFPA 70 (NEC) Sec. 110.3 (B) and Manufacturer’s Instruction. |
| Exposed internal stator, rotor, and shaft surfaces shall be protected against moisture and corrosion by a suitable protective coating during preservation. IEEE Std. 841-1994 |
| One copy of the manufacturer’s standard installation instruction (including weather and winterizing) shall be packed and shipped with the equipment. API Std. 541Sec. 4.4.1 & 6.1.16 |
| Check motor preservation also meet the requirements as mentioned in the data sheet. |
International Codes & Standard References
| 1. SAES-P-100 Basic Power System Design Criteria 30 April, 2007 |
| 2. IEEE Std 841-1994 TEFC- Squirrel Cage Induction Motors 06 June, 1994 |
| 3. API Std. 541 Form-Wound Squirrel Cage Induction Motors June 2004 |
| 4. NFPA 70 National Electrical Code (NEC), 2008 Edition |