Moisture may enter the motor due to various factors: improper storage and maintenance, environmental exposure, condensation, or even dropping the equipment into water. This reduces the insulation resistance of a motor and affects its operation.
The main cause of motor burnout is a decrease in insulation resistance due to the coil wetness. If the motors stored for a long time have been damaged, or their insulation resistance value is below the normalized point, such motors should not be used without repair or drying. The motor should be dried and used only after the insulation resistance has been normalized.
Typical Drying Methods
Typical methods for drying of wet small induction motors include hot air circulation or drying with the use of infrared lamps. Both methods are capable of heating the parts to the required 100 degrees Celsius; however, the infrared lamp method requires more caution, because placing the parts too close to the lamp may cause their damage.
Instead, hot air drying is the optimal method, as it ensures uniform and rapid moisture removal while mitigating the risk of overheating.
GlobeCore SSC Drying Oven
In order to implement this method, GlobeCore professionals have developed an SSC drying oven. Basically, it constitutes a drying chamber made of heat-insulating material, with inner drip trays and airtight sealed doors.
For easy drying, small motors are pre-disassembled and placed on drip trays inside the drying chamber. The process of drying them in the SSC oven is automated; the user just needs to load the parts, set the required temperature, normally at the level of 100°C, and the drying time, which depends on the parts size and wetness.
The air is heated by means of a heater, and the hot air inside the drying chamber is evenly circulated by fans.
It is important to note that due to the maximum drying temperature of 400°C, the SSC oven serves as a multifunctional equipment that can be used for drying, baking, or hardening of various materials and parts.