High Efficiency and High Stability Output
Unlike the conventional safety tester design that uses variable voltage transformer and class AB amplifier to provide testing voltage, the GPT-9900 Series, carrying a high-efficiency PWM amplifier design, generates output source up to 98% efficiency. This greatly reduces the amount of power loss to heat and therefore lowers the temperature within the cabinet of the GPT-9900 series. The suppression of temperature rise during heavy-duty operations of the tester significantly increases its reliability and service lifetime. In addition, as PWM amplifier is comparatively more resistant to the fluctuations of input power voltage, a stable high-voltage output with less than 1% regulation is provided by the GPT-9900 series to perform precision tests of the DUT.
High Accuracy and High Resolution Testing Performance
In order to provide high accuracy testing for production test, regulation compliance, and characteristic verification, the withstanding test voltage (AC 5kV/DC 6kV) of the GPT-9900 Series can be adjusted in 2V steps, while the current measurement can be done with 1μA resolution and ±(1.5% + 30μA) accuracy to enable small leakage current measurements of the products or the components. In addition, the test voltage of insulation resistance of the GPT-9900 series can be adjusted in 50V steps within the DC output range from 50V to 1kV, carrying a measurement accuracy of ±(10% of reading +1 count) at full scale (2000MΩ/9.999GΩ) and ±(15% of reading +1 count) at full scale (50.00GΩ). This provides the flexibility for performing Insulation Resistance (IR) measurements under variable levels of applied voltage. As the majority of safety regulations need an AC source for ground bond testing, the GPT-9900 series provides 6Vac voltage (open circuit) and 3A~32Aac current for ground bond test. Furthermore, open circuit detection (via SOURCE H, SENSE H and SOURCE L terminals) for ground bond test is also provided to check whether the test apparatus is properly connected before the start of a test. This is to ensure the ground bond test is done accurately without any unnoticeable misconnection of the test leads and the test terminals.
With these capabilities, the user is able to perform various safety tests and verifications with high flexibility, accuracy and confidence.
Safety Guarding throughout the Testing Period
Once the GPT-9900 series is turned on, the protection functions to protect operator and DUT are always in operation throughout the testing period. When the power is turned on, the GPT-9900 series immediately goes through the self-check procedures to ensure that all test functions are performed under normal conditions, as the first protection function being applied.
The second protection function is activated once the “Start” (output) button is pressed. At the first moment of start up, the GPT-9900 will send a detection voltage (~100V) during the initialization period (100ms) to check whether the DUT has any short circuit due to poor insulation before the high voltage is applied. This is to prevent high voltage or current from returning to the DUT during the test time. To protect DUT from insulation breakdown caused by the rapid increase of test voltage at power-on and avoid flashover or arcing phenomena that could affect the test results, the GPT-9900 Series has a Zero Crossing Turn-On feature, which ensures the output always starts from the zero crossing of a sine wave. Moreover, the adjustable voltage ramp-up time (0.1s ~ 999.9s) allows the test voltage to slowly rise to the set test voltage to reduce the risk of damaging DUT during mandatory production testing.
Furthermore, after the voltage has ramped to the set test voltage, the GPT-9900 will continue monitoring the voltage and cut off power output once any irregularity is detected. This provides both the safety tester and the operator with a high level protection, which allows the test to be done in a safe and accurate manner.
Multiple Protection Mechanisms
The GPT-9900 series also offers multiple protection designs to ensure operator safety in operating the safety tester. The interlock function provides the hardware key protection for voltage output. When the interlock function is activated, the testing voltage will present at the output ONLY when the dedicated interlock key is attached to the Signal I/O port on the rear side. When the test is not intended to executed, removing the interlock key can inhibit the voltage output to prevent the hazard of high voltage output. Except connecting with the key, two inputs of the Signal I/O port can be connected alone to a senor switch installed in safety test system. If there is any unexpected object is detected to intrude into the system, the output is disabled and thus prevents the operator from exposure to hazardous voltages/currents.
In addition, the GPT-9800 series can quickly cut off the high voltage output within 150µs when the test has completed, the high/low limits have been reached or the emergent stop caused by an abnormal situation. Lastly, when a test has stopped, the unit also automatically discharges the voltage across the DUT to reduce the risk of injury to operator.
Friendly User Interface
The 240 x 64 LCD displays not only the setting parameters but also the test conditions, measurement values and DUT inspection results (PASS or FAIL) in a legible pattern. The LED indicators in different colors alert the operator to the status of the safety tester to avoid any possible risk. For example, the status indicator sitting above the high voltage output terminal will automatically blink when a high voltage presents at output. In addition, the function keys arranged below the LCD display provide convenient operation that test setup can be easily done by fewer key punches.
Convenient Manual and Automated Test
In order to comply with all safety regulations, the GPT-9900 series also offers a large number of memory locations (100 sets in total) to store a variety of test conditions. When a test condition is saved to one of the 100 fixed memory locations, a unique test file name (up to 12 characters) can also be assigned to its memory location. For example, the test file name “IEC61010AH” (IEC61010 AC Withstanding test) can saved and recalled for future use. Any test conditions that have been previously stored can be used for a single test or combined together for automatic testing- eliminating the need to perform a series of tests manually.
In addition to using the START/STOP buttons on the front panel to control the safety tester, the GPT-9900 series also provides a remote terminal for connection to an external remote controller and a signal I/O port on the rear panel for connection to a PLC interface for actuator control. Furthermore with RS-232C and USB as standard (GPIB optional) for all the models in the GPT-9900 series, retrieving test data and results is convenient via a PC connection.