This test is non- destructive providing that it does not fail and is usually required by safety agencies to be performed as a 100 production line test on all products before they leave the factory.
Ceiling Fan Winding Calculation Trial Automation FlightCommon Electric Motor Types AC Induction Motor Squirrel Cage Wound Field Brushed DC Motor AC Synchronous Motor Permanent magnets Wound field Brushless ACDC Motor Switched reluctance Motor Linear Motor Flat Tubular Stepper Motor Permanent Magnet (PM) Variable Reluctance (VR) Hybrid Stepper Linear Brushed DC Motor Construction and Performance Easy to predict motor performance Simple, inexpensive control electronics Use of a feedback device is optional Difficult to design brush system Limited availability of the brush system components Very difficult to predict brush life Not a motor of choice for high-performance application Manufacturing cost very low for mass production, when fully tooled Typical applications for Brushed DC Motor Appliances Hand Tools Automotive Manufacturing Military and Commercial Aerospace Manufacturing AutopilotAuto-throttles Fin Controls Gimbals Optics Radars AC Induction Motor Construction and Performance Easy to predict motor performance for a three-phase motor windings, notoriously difficult for a single-phase designs Limited availability for copper fabricated rotors Still a popular choice for a new 400 Hz military and commercial aerospace applications Low manufacturing costs low for mass production, when fully tooled Typical applications for AC Induction Motors Fans Blowers Military and Commercial, rotary or fixed wing aircraft Industrial Automation Flight Controls Radar Drives Environmental Control Systems ThrottlePilot Interface Devices Oil Gas Downhole Tooling Pumps Valves Hybrid Stepper Motor Construction and Performance Difficult to predict motor performance, based on design experience Attractive for some space applications when feedback device not required Can require precision lamination stamping Motor winding similar to a brushless DC design Manufacturing cost very low for mass production, when fully tooled Typical applications for Stepper Motors Low Precision Positioning without Feedback Device Positioning Optical FilterLenses with Feedback Device Robotic Joint Positioning Pan Tilt Assemblies Low Power, Low Speed Scanners Radar Drives (limited rotation, low inertia or power) 3D Printers Proportional Valves Hydraulic, Fuel Control etc.Brushless DC Motor Construction and Performance Easy to predict motor performance, however extremely drivecontroller dependent Motor of choice for new andor high-performance applications Very high power density Very high speeds Very high efficiency Requires a feedback device Read about how magnet selection and implementation affect the overall performance of a BLDC motor Typical applications for Brushless Motors Highest Performance Applications Fin Controls TVC Controls Multi-Mode Radar Drives Weapons Gimbals Turret Drives Primary Secondary Flight Controls High speed High Power Pumps Fans Vehicle Traction Drives High Reliability and Storage Life Switched Reluctance Motor Construction and Performance Electronically Commutated No permanent magnets High torque ripple Difficult to predict motor performance Once was a major alternative to induction and brushless DC designs Manufacturing cost low for mass production, when fully tooled Typical applications for Switched Reluctance Motor Appliances Hand Tools Automotive Manufacturing Locomotive Traction Linear Motor Construction and Performance Easy to predict motor performance Very high speeds Very high precision Best for lightlow inertial loads Limited travel lengths Motor of choice for new andor high-performance applications Manufacturing cost high Typical applications for Linear Induction Motors Small Linear Motors Semiconductor Manufacturing Flat Panel Manufacturing Conveyor Systems Airport Baggage Handling Accelerators and Launchers Pumping of Liquid Metal Large Linear Motors Transportation (Low Medium Speed Trains) Sliding Doors Closure (Malls, Metros) People Movers Material Handling and Storage Commonly Used Sensors ResolversSynchros Industrial Servo motors Aerospace and Military Down hole oil and gas exploration Applications with high temperature and mechanical vibration requirements Difficult to predict performance Difficult to achieve high accuracy due to manufacturing variances Manufacturing cost can be low in mass production, when fully tooled No new development, mainly second source by matching resolver performance ElectromagnetsSolenoids Industrial Magnetic mechanical support Automotive Commonly Used Materials Magnetic Materials Carbon steels Stainless steel Silicon steels High saturation alloys Amorphous ferromagnetic alloys Soft magnetic powder composites Nanostructured materials Ceramic Alnico Rare Earth Dielectric Materials Paper Epoxy Plastic Magnet Wire Copper Aluminum Litz Commonly Used Materials in Our History Carbon steelsStainless steels Silicon steelsHigh saturation alloys Examples Material Type Core Loss Saturation Flux Density Permeability Ease of Processing Raw Material Relative Cost CRML Steel Fair Good Good Best 0.5 Non-Oriented Silcon Steel Good Good Fair Good 1.0 Grain-Oriented Silcon Steel Better Good Better Fair 1.25 Amorphous Alloy-Iron based Better Fair High Much Care Required 1.25 Thin-Gauge Silicon Steel Better Good Good Fair 10 6-12 Nickel-Iron Alloy Better Good Good Care Required 12 49 Nickel-Iron Alloy Better Fair High Care Required 12 80 Nickel-Iron Alloy Best Low High Care Required 15 Cobalt-Iron Alloy Good Best Better Care Required 45 Powdered Alloys-SMC The ultimate properties and cost of SMC materials are determined in large measure by the design of the machine and thus are not referenced in this table Examples Deterioration of Magnetic Properties due to Punching Fully processed material is simply material which has been annealed to optimum properties at the steel mill.Even though annealed at the mill, fully processed material may require further stress relief anneal after stamping.
The stresses introduced during punching degrade the material properties around the edges of the lamination, and must be removed to obtain maximum performance. This is particularly true for parts with narrow sections, or where very high flux density is required Commonly Used Magnet Materials Material Magnetic Properties Magnetic Characteristics Curie Temperature Temperature Coefficient of Induction Cost lb. ![]() Because of its lower electrical conductivity, aluminum wire requires a 1.6-times larger cross sectional area than a copper wire to achieve comparable DC resistance. Insulation Modern magnet wire typically uses one to four layers of polymer film insulation, often of two different compositions, to provide a tough, continuous insulating layer. Classification Magnet wire is classified by diameter (AWG SWG or millimeters) or area (square millimeters), temperature class, and insulation class Stators Most Common Constructions Rotors Constructions Electric Machine Parameter and Testing Part 1 Mechanical Dimensions Geometric Dimensioning and Tolerancing (GDT) is a system for defining and communicating engineering tolerances. It uses a symbolic language on engineering drawings and computer-generated three-dimensional solid models that explicitly describes nominal geometry and its allowable variation. It tells the manufacturing staff and machines what degree of accuracy and precision is needed on each controlled feature of the part. GDT is used to define the nominal (theoretically perfect) geometry of parts and assemblies, to define the allowable variation in form and possible size of individual features, and to define the allowable variation between features. Ceiling Fan Winding Calculation Verification Electric MachineASME standards ASME Y14.5 Dimensioning and Tolerancing ISO TC 10 Technical product documentation ISOTC 213 Dimensional and geometrical product specifications and verification Electric Machine Parameter and Testing Part 2 Electrical parameters Example: Measure and record A-B, B-C, C-A line-line resistances and inductances. Hipot and surge test the stator after varnish at 1800VAC, max current leakage 5mA Before and after varnish, perform corona test(partial discharge) with pulse up to but not exceeding 3000V. Resistance The electrical resistance of an electrical conductor is the opposition to the passage of an electric current through that conductor. Electrical resistance shares some conceptual parallels with the mechanical notion of friction. NEMA MG 1 Find contaminations and defects in phase-to-ground insulation 2 Polarization Index IEEE 43 Find contaminations and defects in phase-to-ground insulation 3 DC High Potential Test (Dielectric Withstand Test) IEEE 95, IEC 34.1, NEMA MG 1 Find contaminations and defects in phase-to-ground insulation 4 AC High Potential Test (Dielectric Withstand Test) IEC 60034 NEMA MG 1 Find contaminations and defects in phase-to-ground insulation 5 Surge Test IEEE 522 NEMA MG 1 Detects deterioration of the turn-to-turn insulation 6 Partial Discharge Test IEEE 1434 Detects deterioration of the phase-to-ground and turn-to turn insulation 7 Dissipation-Factor IEEE 286 IEC 60894 Detects deterioration of the phase-to-ground and phase-to phase insulation Electric Machine Parameter and Testing High Potential Test Three types of High Potential Test tests are commonly used. These three tests differ in the amount of voltage applied and the amount (or nature) of acceptable current flow: Insulation Resistance test measures the resistance of the electrical insulation between the copper conductors and the core of the stator. Usually, lower the insulation resistance, it is more likely that there is a problem with the insulation. The test voltage is increased until the dielectric fails, or breaks down, allowing too much current to flow. The dielectric is often destroyed by this test so this test is used on a random sample basis. This test allows designers to estimate the breakdown voltage of a products design and to see where the breakdown occurred. A standard test voltage is applied (below the established Breakdown Voltage) and the resulting leakage current is monitored. The leakage current must be below a preset limit or the test is considered to have failed.
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