The instrument is a bench-type Dielectric Withstand Tester with DC Output, designed for production line testing. The HT-2800 features automatic one-button operation, with numerous safety features designed to protect the operator: ? The Return Lead is directly connected to ground potential for operator safety. ? In case of trouble, the test can be immediately terminated at any time by pressing the RESET button. ? Before the test can commence, the unit must be armed by pressing the RESET Button. The test will not begin until the TEST Button is pushed. ? If a failure is encountered, the high voltage is immediately cut, a buzzer sounds, and any voltage stored in the equipment being tested is bled off by a resistor bank in the HT-2800. Voltage discharge progress is shown by the front panel meter. ? Failure modes are shown by the front panel LED's for quick troubleshooting. Convenience and testing features include: ? Test results are determined quickly, without operator intervention. ? Operator instructions are printed on the rear panel for quick reference. ? The HT-2800 allows custom setups for voltage ramp, test time and leakage limit. ? The continuity check can be defeated by a switch on the rear panel for testing of products using a two wire power supply cord. Voltage is discharged by resistor bank within the HT-2800 upon test completion. Discharge progress is shown on the front panel meter. Ground continuity pass/fail resistance level is adjustable during the annual calibration procedure. A 120kohm resistor is supplied on the rear panel for leakage current checks and adjustment. The HT-2800 meets all safety agency criteria for automatic production line dielectric withstand testers. An Introduction to Dielectric Withstand Testing with the HT-2800 The continuity test/dielectric withstand test is a production line test which is recognized by safety agencies worldwide as a valid criterion of safe assembly of end-use equipment. The test ensures that the primary circuit power and ground conductors were properly wired and connected for safe operation. It also applies a high-voltage potential between power and ground conductors to make sure that no unintentional leakage or arcing paths exist between power and ground. The test consists of a continuity check, a leakage current check and a high voltage check. It is non-destructive to the equipment under test, and can be accomplished in a short time. Safety Precautions The dielectric withstand test generates voltages of up to 2800 volts dc at potentially lethal current levels. Currents of as little as 5 mA at 120 volts can cause death, and the HT-2800 is capable of generating 5 mA at up to 2800 volts. Because there is no zero volts crossing point as there is for ac voltage, dc voltage is considered the more dangerous of the two. It is more likely that a person will be thrown clear or be able to extricate himself from ac because of the zero crossing. The HT-2800 has been designed to minimize exposure to high voltages. However, the potential for serious injury or death exists and personnel should be aware when they conduct this test. Test Personnel Personnel require special training to conduct the dielectric withstand test. They should understand electrical fundamentals clearly, and be aware that high voltage is adept and creative at completing a path to ground. Instructions should include a warning against any metal jewelry. Operators should not allow others in the testing area, especially when tests are being conducted. Organization is to be stressed. The operator should keep the area free of unused leads and equipment. Testing Area The area used for conducting the dielectric withstand test should be as remote as possible from normal production line activities. Only personnel actually conducting the test should be allowed in the area, and it should be taped or roped off to preclude casual entry by other employees. In addition, the area should be marked "WARNING - HIGH VOLTAGE TESTING" or the equivalent to warn others of the nature of the testing taking place. The bench being used should be non-conductive, and any exposed metal parts should be tied together and grounded. If a conductive surface must be used, it should be grounded. Because of sparking during a dielectric test failure, it is not safe to conduct dielectric withstand tests in combustible atmospheres.