For safe, long-term use of a compressor, the motor winding temperature must be kept below certain limits, in all conditions in which the appliance may operate. For example, compressors from AC ...

Transformers are very reliable devices and can provide service for a long time if regularly maintained and serviced. They’re also the single most costly item in any substation. To protect against ...

Megohmmeters (meggers) are electrical meters used to check the resistance and condition of the motor windings and the condition of the refrigeration and oil environment around the motor windings. A ...

HIOKI recently announced the launch of the Impulse Winding Tester ST4030, which is the company’s first instrument to provide functionality for testing for defects in motor windings. HIOKI provides a ...

This test set uniquely combines winding resistance measurement, transformer turns ratio, tap changer dynamic resistance, core demagnetization, transformer type detection, magnetic balance, short ...

The Tettex 2293 from Swiss firm Haefely Test AG is the result of extensive research and years of experience testing transformers. A simple one-time-connection system, together with the simultaneous ...

In the first installment of this series, "Calculating a practical hotspot safety margin", we discussed how two-parameter thermal models assume that the entire motor, including windings, exhibits one ...

Whenever a power or distribution transformer is isolated from the power system, it is probable that residual magnetism remains in the core due to the phase shift. However, residual magnetism also ...

The types of insulation used in rotating machines have continued to evolve and precipitate changes to insulation resistance testing since 1974 when IEEE Std. 43, Recommended Practice for Testing ...

Power electronics are rapidly expanding into new applications as high-power semiconductor devices increase their rated operating current and frequencies to higher and higher levels. As a basic ...