Recording of cooling curve on motors

• Measuring range 200 μΩ ... 20 kΩ
• Resolution up to 1 nΩ (1 . 10-9 Ω)
• Accuracy ≤ 0.01 % of reading
• Special current regulation for inductive probes
• Automatic temperature compensation 

Task

Recording of a winding's cooling curve after long term stress.

Specific requirement

Up to 255 measurement values can be stored in a freely selectable time interval. After completion of the measurement the values are displayed in tabular form respectively can be transmitted to a PC for further data processing.

Solution

By using a RESISTOMAT® 2304, KELVIN test tongs 2386-V001 and a temperature sensor 2392-V001 the first based "cold" winding resistance will be measured at 20 °C. The DUT is operated for several hours with rated load. After disconnecting the DUT power supply, time set is started in RESISTOMAT® 2304 and the KELVIN test tongs are clamped to the DUT. During the cooling process the value pair resistance and time will be recorded at the preset cycle time.