Stator testing 1

[southward]

In API 546 Stator core test for Interlaminar insulation deficiencies (hot spots) are defined as being any core location 5°C above the adjacent core temperature.

Does anyone have a precise definition of what "adjacent means" is it the next laminiation, a number of laminations or an area of the stator (say a quadrant.)

 

[PDAGuru]

No, I don't think anyone has a precise definition of "adjacent" core temperature. Its kinda subjective, like asking 'how long is a piece of string?' In a thermal scan, it could be interpreted as 5 C above the temperature of the surrounding area (i.e. the blue area, hopefully, around the red/orange spot).

The ELCID test is a more precise technique, measuring the interlaminar fault current circulating as a result of a short between even just two laminations. It shows the precise location (e.g. slot tooth number and axial distance from the slot end) of any interlaminar short circuits.

There is no hard & fast formula for translating ELCID measurements to ring flux / loop test temperature rises but a rough rule of thumb is that every 100 mA of ELCID fault current is approximately equivalent to a 10 C temperature rise.

Hope this helps.