Effective Electric Motors Rewind for Houston!
Is Electric Motors Rewind cost-effective versus replacing an electric motor? You may be looking at spending big money replacing standard efficiency motors with energy-efficient models, but one just failed. Therefore, do you rewind an electric motor or replace it?
A knowledgeable service center like Community Motors, Inc. in Texas can rewind energy-efficient motors without a loss of efficiency. However, make sure you discuss specific procedures with us before sending a motor out for rewind. Ask for a electric motor repair report, and build guidelines into it to ensure you get the best repair.
Winding resistance (corrected to standard ambient) serves as a good quick-check, and core-loss test results confirm no damage resulted from the motor failure or burnout process. Most importantly, insist on documentation.
CMI Electric Motor Rewind Diagnostics and Assessment
What to look for: First, take a stator core apart, and you have a pile of laminations. These are thin pieces of steel, coated with insulation to reduce eddy-currents in the core. Secondly, if you take a motor apart post-mortem, look for core damage: a hole, evidence of rotor drag, or laminations fused together. Subsequently, check the windings.
To remove the old windings, most shops process stators in special burnout ovens to burn off insulating varnishes and epoxies. They maintain the appropriate oven temperature to preserve the core’s interlaminar insulation. The insulation reduces efficiency-sapping eddy currents. Consequently, newer insulations can withstand higher temperatures than previous formulations. Therefore, winding insulation materials burn at lower temperatures than the interlaminar insulation, a proper burnout process won’t harm the interlaminar insulation.
A recent study settled on 750 DegrF for standard laminations. It showed oxide-coated newer steel laminations could withstand temperatures in excess of 900 DegrF with no loss of efficiency. As a result, the Electrical Apparatus Service Association (EASA) recommends oven temperature should not exceed 680 DegrF for organic or 750 DegrF for inorganic interlaminar insulation. The repair shop should perform a core-loss test before and after removing the old windings. The watts/pound readings help determine if the core is good, and safeguard against burnout problems.
Commercially available core testers simplify the process and usually provide printouts documenting the core’s condition. Alternatively, they can use a wattmeter, power supply, and some manual calculations to determine core loss.
