It is time to get generators and motors ready for the long hot summer. For many this includes cleaning their critical motors and generators for the upcoming summer months.
Carbon Dioxide (CO2) (Dry Ice) cleaning has been gaining in popularity for many large machine users to accomplish this dirty and time consuming task.
Dry Ice blast cleaning for generators and motors can be used for:
- Removal of carbon deposits
- Removal of grease/oil build up
- Cleaning of buss bars, Stator, Stator Core, Rings, Windings, and other components
Among the advantages reported include:
- Reduced chemical usage (reduced V.O.C.
- Increased speed in the cleaning process
- Dry ice blast is non-abrasive compared to conventional methods
- No drying time
Dry ice blasting is best used for loose service contamination on hard non-porous surfaces. Depending on the skill of the operator, the contaminates are reduced considerably on the first pass and nearly eliminated after two or three more passes. Dry ice blasting can be completed much faster than other conventional processes using walnut shell, corn cob, or baking soda as an abrasive. While the actual time spent performing the blasting (cleaning) may be longer, the minimal drying time and clean up once the work is completed makes this a much more efficient option for cleaning your machines.
While dry ice blasting has several advantages it also has its limitations. The blasting requires a line of sight for the operator, and some areas of a machine cannot be cleaned even with the many new cleaning nozzle designs available. So there most likely will always need to be some machine disassembly.
The last possible disadvantage of dry ice blasting is the skill level of the operator. With dry ice blasting if the CO2 pellet size is too large and/or the pressure too high the process becomes too aggressive and can damage insulation and coating systems. So verification of your service provider’s qualification and training program for their operators is a must prior to bringing this cleaning method into your plant.
– Article provided by our friends at PdMA. Contact us for all of your PdMA MCE testing and preventive maintenance needs!
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two magnetic fields that push or pull each other to make the armature rotate. Recording a winding resistance value on these components is a common practice during de-energized motor testing for trending or troubleshooting. When it comes to measuring winding resistance, remember our tip that smaller is bigger. The smaller the wire size the bigger the resistance. The rotating armature windings, connected to the commutator, are relatively large and in many industrial DC motors are form wound. The stationary series windings are randomly wound around the pole pieces and are also relatively large. By relatively large we mean that if you look at an individual strand of copper wire that makes up the armature or series winding, the diameter or circular mils of the strand is larger when compared to the shunt field windings. The shunt field windings are also randomly wound around the same pole piece as the series winding but consist of much smaller strands of wire when compared to the series and armature windings. Therefore, true to our tip, on smaller shunt field windings you would expect a bigger resistance reading. Having a basic understanding of these two components will make you more effective when analyzing the data received when performing a winding resistance test on a DC motor. To learn more from PdMA about motor analysis and troubleshooting, click