Wound Component EST Analyzer – 19036

The 19036 is equipped with a patented 4-wire DC resistance test that has both Drive and Sense in compliance with withstanding specification and provides 10 channels of 4-wire DC resistance test functions. Up to 40 channels of scanning test can be conducted when the 19036 is configured with the optional 16 channel external HV scan boxes.

The 19036 includes Flashover Detection built-in. Flashover is an electrical breakdown of a gas that produces an ongoing plasma discharge, resulting from a current flowing through normally nonconductive media such as air. Since flashover cannot be simply detected by the leakage current rms value, the Flashover Detection feature is an invaluable part of the HV test. For Contact Checking during the hipot test, the 19036 is equipped with a High Frequency Contact Check (HFCC). By conducting the Contact Check during Hipot test, it can increase the test reliability and efficiency significantly by identifying test fail problems caused by bad contact of cabling or the test fixture.

Measurement Technology

HI-POT Test Flashover Detection arc
Fast transient on detected leakage current is defined as flashover in hi-pot test. The 19036 has Flashover Detection as other Chroma safety test series. Flashover is nonsequential discharge generated by the inner or surface of insulation component which cause DUTs to lose original insulation feature, generated carbonation electrically conductive path and damages the product. As flashover cannot be detected by leakage current rms value, Flashover Detection is one of the inevitable inspection items in HV test.

Impulse Testing Overview
The impulse winding test is to impose a non-destructive, high speed and low energy voltage impulse on the DUT (Device Under Test) to analyze/compare the equivalent waveform of yield and defect products for good and no good judgement. The main function of impulse winding test is to discover the potential defects such as layer short, corona or partial discharge that is difficult to find in wound components in the early phase.
Four Kinds of Waveform Judgement for Testing

• Area size
• Differential area
• Flutter value
• Laplacian value

Use Laplacian for calculation can detect the waveform discontinuity caused by electrical discharge effectively.

DCR Measurement

• DCR Measurement (two-wire/four-wire)
  Chroma 19036 can choose to use 2-wire or 4-wire DCR measurements. The new patented port design provides maximum 10 channels 4-wire DCR measurements for high accuracy tests on multiple wound samples like motors and transformers. The measurement range is from 0.1mΩ to 500KΩ.
• DCR Balance
  When the DCR of the motor with 3 windings is unbalanced, the rotation will not be balanced as well and it could cause bad quality for long term use. The judgement of DCR balance is to subtract the maximum and the minimum value of winding and the product is no good if the value exceeds the set range. It is a reliable assistant tool for testing motor products.
• Temp Compensation
  When measuring a smaller DCR, it often encounters the problem of temperature difference. The measured resistance is varied with the temperature. Thus, the temp compensation function is included in the 19036. Through the conversion of temperature coefficient, it changes the DCR to the measured value under standard temperature to reduce the influence caused by temperature difference.

High Speed Contact Check (HSCC)
If an open occurs to electrical safety testing circuit it may cause a defected product to be judged as a good one. The contact check can detect and screen the products when short circuit occurs to reduce the damage of fixture device and save the test cost. The HSCC function can scan rapidly if the DUT circuit contact is correct . This new technology allows the contact check before hipot test to be done faster than ever. The 19036 also has High Frequency Contact Check (HFCC) and Open Short Check (OSC, Patent no. 254135) functions that can detect if there is Open (bad contact) or Short (DUT short circuit) between the winding and the iron core.

Substep for Testing Multiple Wound Components

Parallel hipot test is often used to improve the manufacturing inspection speed; however, it is unable to set the current high/low limit correctly when doing a parallel test and it causes the leakage of defected products or misjudging the good to no good. It also adds workstations for testing the defected products and increases the cost. The 19036 offers the sub-step function to solve the trouble caused by the parallel test. When the parallel test is required for production, it programs fail as the sub-step launch condition which means only when the main test item (parallel) fails the sub-step test item (single) will be performed to judge the defect DUT. The implementation of this function can optimize the productivity and quality inspection.

GFI Human Protection

The ultimate purpose of safety testing is to protect users from electrical hazard.The19036 also has GFI function to protect the operator. The GFI function can cut off the power output immediately while the human body is suffering electric shock. The GFI function detects the current from earth GND (Ioperator) and LOW terminal (Idevice). The voltage output will be cut off if the current is over 0.5mA.

Product Applications

From EV motors, servomotors, ascension motors to fans all rotary motor products need to perform impulse test, hipot test and DCR measurements to ensure the product quality also refer to JB/T 7080 GB Machinery Industry Standard for testing. The DCR measurement of the 19036 is in 4-wire type and each terminal has Drive and Sense total 10 independent channels for scanning test 3 DUTs at once to increase productivity. Each channel can be set to Hi/Lo/Open respectively.

Y-type motor for example, the test items are:

• HSCC / OSC
• DCR Test
• Impulse Test
• Hi-pot –Sub step test

△-type and Y-type motor
To solve the problem of unable to do DCR measurement on the △-type and Y-type motor winding (no center-tapped) directly, Chroma 19036 has added △-type and Y-type motor winding DCR calculation functions to obtain the value of R1, R2 and R3.

40 Channels scanning test
A190359/A190362 (4-wire) scanner has 16 test channels and each of them can be set to H (High voltage, Hi), L (High voltage, Lo) or X (Open). The combination of 19036 and A190359/A190362 (4-wire) can apply to multiple PINs or small amount but diversified DUTs as well as cell type production line to complete all tests within one station.