Product Announcement from SKF USA
This semi-custom instrument is assembled from standard components to customer's specifications. The tester's capabilities are not limited to those described here - other features are available. Please feel free to discuss modifications with an SKF representative.
Baker WinTATS Operation
The Baker WinTATS is a rack-mounted system that contains a Windows 7-based computer, power supplies, and measurement circuits. A precision-positioning armature indexing stand is included. In operation, the armature to be tested is loaded onto the indexing stand. The standard test sequence consists of DC and/or AC hipot tests, a resistance test, and a surge test.
- Automation: The Baker WinTATS is a fully automatic, masterless armature test system. The operator does not set the test voltages or pass/fail limits before each test. All test parameters and pass/fail limits are preprogrammed in a Master file. This instrument is programmed using a simple menu and is prompted to input test parameters and pass/fail tolerances for each test. Typical programming time for a new Master file is only a few minutes. To avoid corrupted data unauthorized personnel can be locked out of the programming mode. To conduct a test, an operator simply recalls a Master file. The armature is connected to the tester and then the tester automatically sets the test voltages, takes the measurements, and gives a pass/fail signal. The test data is then displayed on the screen for review.
- Software: The Windows 7-based software package included with the Baker WinTATS helps manage and record the results of tests. The system automatically maintains all master and test results on the hard drive. During normal operation these files are saved and organized so that they can be easily accessed by the user in a variety of ways. All access and manipulation of these files can be performed through the Windows based software interface.
Baker WinTATS Testing
- AC & DC Tests: For AC hipot testing, the Baker WinTATS uses arc detection to sense breakdowns to ground or between windings which would otherwise go undetected using average current measurement techniques. It also has capacitive compensation capability. This measures the resistive portion of the leakage current, rather than the total current. DC hipot testing checks the integrity of the insulation system with high DC voltage. Leakage current is then measured in microamps rather than milliamps.
- Surge Tests: The high voltage surge or impulse test checks for insulation problems between turns, coils, and bar-to-bar.
- Resistance Tests: The most frequent fault encountered in the manufacturer of armatures is a poor connection between the coils and the commutator. A common name for this type of fault is a a weld fault. It becomes apparent when either a high resistance is measured or an open condition is detected at the faulty connection. The resistance test is conducted to find this problem as well as wrong wire size, stretched wire, misconnections, and dead shorts. It uses an autoranging DC constant current supply to measure the resistance of a winding. With the use of Kelvin connections, low resistance winding tests are accurate and repeatable. Resistance measurements between 20k and 2mΩ are corrected for temperature to the equivalent resistance value at 25°C or to a customer specified temperature.
A rugged custom test fixture is provided with the Baker WinTATS for testing your armatures. The purpose of this fixture is to provide a means of quickly connecting the armature to the tester and providing safety to the operator. The armature is rotated by means of a rubber drive wheel contacting the core of the armature. The wheel is driven by a stepper motor under computer control. Usually, one or two optical sensors are used to sense the commutator slots as the armature rotates. Either an encoder or the stepper motor pulse count is used to sense that the distance between slots are similar when indexing the armature.