February 05, 2007
Question of the Week: Commissioning
President, SUCCESS by DESIGN
Do you know where I could get a concise list of inspection criteria to use during witness testing of large, medium voltage (4000V) motors, both with rolling element bearings and sleeve bearings?
This is an excellent question. It involves one aspect of commissioning equipment that many companies have lost track of with cost cuts. Unfortunately, many organizations do not realize the long and short term savings related to on-site witness inspections, vendor audits and other aspects of the acceptance inspection portion of commissioning. Mind you, the planning of what equipment is being commissioned is important. It should not be limited to just the size of the motor, but also the criticality of the system the motor will be installed into. In effect, the witness testing can be performed on virtually any sized motor.
The inspection criteria, itself, should be part of a repair specification that the repair vendor has agreed to. This will have the multiple benefit of the vendor paying more attention to your equipment, which will naturally reduce the number of defects and reduce the risk involved in motor repair, provide a checklist for the acceptance staff and will establish standardization.
References:
1. The NEMA MG-1: http://www.nema.org
2. The EASA/ANSI AR-100 repair specification: http://www.easa.org
3. IEEE Std 1068 repair specification: http://www.ieee.org
4. The IEEE Electrical Machinery Collection: http://www.ieee.org
For more information on developing your repair specification, acceptance and commissioning criteria/best practices and qualifying repair shops, email:
