M&C works closely with both local and international insulation and resin manufacturers to ensure that the best insulation systems are implemented, and the highest repair standards are achieved. It is crucial to understand that any motor’s reliability is only as good as the “weakest link” in the chain. The insulation system can therefore significantly improve the motor’s reliability and dependability and ultimately reduce the customer’s Total Cost of Ownership.
M&C’s insulation systems have been thoroughly researched and have proven themselves over many years. We make full use of the supply and technical expertise of the insulation companies available to us – and we attend international insulation conferences to keep abreast of international developments. This ensures that we optimise the complete manufacturing process, namely: quality, consistency, delivery, logistics and pricing, starting from the round solid copper conductor, throughout the process to the finished coil.
Furthermore, our manufacturing process is customized and streamlined to provide the fastest possible turn-around time, while still maintaining the highest level of quality and consistency.
The bare copper conductor is extruded or drawn to the required size, as specified by our custom-developed coil design software. The quality of the product is carefully monitored throughout this process. The drawn bare copper is then annealed in an inert gas oven to ensure the correct “softness” as well as to eliminate oxidation and contamination. The conductor is then covered as per our proven insulation standard, being either pure Nomex™, Kapton™, Apical™, Mica, Polyester or other materials. The details of our insulation systems remain a closely guarded secret. The main-wall insulation utilized has been carefully researched in order to provide the optimal balance between insulation properties, heat transfer and value-for-money.
The application of the main wall insulation is by means of specialized high speed precision automatic taping machines and highly trained and skilled specialist insulation artisans. The partial discharge protection (also referred to as Corona Discharge) prevention has been carefully developed to ensure the long term reliability of our windings. It is not uncommon for a new stator winding to outlast the generation that installed it. The system is however not complete without the correct application of the impregnating resin or varnish. Here also, M&C is leading the electric motor repair and manufacturing industry with its range of insulation plant, equipment, systems and materials.
We have successfully implemented the EpoVolt HV™ Epoxy based VPI system. This system is effectively used in our custom designed SCADA controlled VPI (Vacuum Pressure Impregnation) system. Our capacitance measurement system keeps a watchful eye over the process to ensure that the impregnation cycle is complete. Our system is not partially implemented as the industry standard, but fully implemented and includes all of the impregnation system stages: Starting with the pre-heating, vacuum cycle, pressure cycle, transfer to oven, and curing cycle. Our temperature controlled curing ovens ensure that the insulation system is fully cured.
As they say, the proof of the pudding is in the eating: We are extremely proud that our insulation and VPI system fully complies with the most stringent Tan Delta specification in the industry – not only for repaired motors, but also for new OEM motors.
These consistent results are proof of the quality of our complete insulation system.