Insulation resistance testing is a simple yet critical preventive measure that can significantly lower your maintenance costs. You may be familiar with the role insulation resistance testing plays in ...

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 ...

Measuring the electrical resistance (ohms) of motors, compressors, and other electrical devices in HVAC systems may seem straightforward. But when the measurements of zero (0) or “OL” (overload) come ...

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 ...

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 ...

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 ...