The basics of drop testing, as well as offers tips for interpreting the results. Both the AC and DC drop test are described as well as the advantages and drawbacks for each.

2009年5月1日 · The Rotor voltage drop test is used to identify the presence of shorted turns in the salient poles of the rotors of synchronous machines. The test works by measuring the impedance of each pole on the rotor. If there are short-circuits in the rotor winding, the impedance of the rotor poles will be less. The equipment required is relatively simple.

By measuring the voltage drop of every pole between the pole winding connectors, the impedance can be determined. A comparison of the measurement results of each pole or with previous measurements identifies possible inter turn faults in the pole winding. The patented CPC 100 multi-functional test system replaces several individual testing devices.

The “megger” part of the test consists of applying a steady DC voltage to the winding under test. For most stators 13,800 and over, most OEMs call for 5,000 to be held for 10 minutes. For rotor windings, 500 VDC is the standard voltage.

In this paper, new guidelines on testing and interpretation of the pole drop test for improving the sensitivity and reliability of fault detection are presented. An analysis shows that the performance of the test is influenced by the test conditions (rotor in/out, ac/dc voltage) and fault indicator used.

2018年2月4日 · Perform dc dielectric withstand voltage tests on machines rated at 2300 volts and greater in? accordance with ANSI/IEEE Standard 95. Perform phase-to-phase stator resistance test on machines 2300 volts and greater.

DC Input Arm “ Validate the results of the AC voltage drop with a DC voltage drop test and compare results. The AC voltage drop should be within 10% of the average and the DC voltage drop should be within 5% of the average.” By Chase Fell Precision Coil and Rotor Birmingham, Alabama Technical Education Committee Member

• PI readings should be done at the same voltage as the IR test and can be used as a go/no-go test before subjecting the rotor to subsequent high voltage tests, either AC or DC. IEEE Std. 43, Ch. 12 has a long paragraph on the significance (or lack thereof) of 15 Polarization Index measurements on rotors.

The AC drop test is a well accepted tool utilized by maintenance technicians to quantitatively asses the health of the DC wind-ings on the field of a synchronous motor. The drop test is performed by connecting an AC voltage across the entire synchro-nous field and measuring the voltage drop across each field pole independently.

D. AC Pole Drop Test for Salient Pole Rotors. The pole drop test is used to detect shorted turns in salient pole windings and involves applying a singlephase ac voltage of around 120 to 240 V across the complete winding and measuring the voltage drop across each pole [1].