70-, 120- and 160-kV DC High Voltage DC Dielectric Test Sets 70-, 120- and 160-kV DC High Voltage DC Dielectric Test Sets Available in analog and digital models Lightest weight available in air-insulated high-voltage model Advanced performance with long-term reliability provided by filtered half-wave rectification Designed for maximum operator safety Digital Model, Cat. No. 220070 DESCRIPTION APPLICATIONS The High Voltage DC Dielectric Test Sets (70, 120 and The dc dielectric test sets are used to make proof tests and 160 kV) provide the most dependable, portable dc high- insulation tests on electrical power cables, motors, voltage sources for checking the quality of electrical power switchgear, insulators, transformers and capacitors. Both cables, motors, switchgear, insulators, transformers and types of tests are performed by applying controlled high capacitors. Each portable set (heaviest is 73 lb, 32.8 kg) is voltages to the unit under test at or above insulation comprised of two separate modules: system operating level. Measuring the leakage current helps determine the unit under tests ability to withstand Control Module overvoltages such as lightning strikes and switching surges. This module allows the operator to switch-select the The three models described cover a range of output appropriate current output range, adjust the output level voltages that meet the most commonly specified ratings and monitor both the applied voltage and leakage current in5-kV to 69-kV class cable. All are suitable for testing at a safe distance from the high voltage being delivered to power cable, switchgear and rotating machinery in the load under test. No voltage higher than input ac power accordance with IEEE, IPCEA, NEMA and ANSI guidelines. is present in the control module. Proof Test High-Voltage Module Proof testing is used for acceptance testing of newly An air-insulated design receives its instructions from the installed cable and maintenance testing of aged and/or control unit. It generates the dc high voltage that is repaired cable. For the proof test, the unit under test will delivered to the load under test. either withstand the test voltage or it will break down, Although a different control module is used with each of providing the user with a go/no-go answer. the three models, they are all the same size and weight. Insulation Resistance Tests Each high-voltage module is a different size and weight to To make appropriate tests on healthy insulation, the test accommodate the rated output voltage. instrument must have microampere sensitivity. Insulation resistance can be measured in at least three different ways: The insulation resistance test is often referred to as a spot check, and is performed by applying a predetermined voltage to the unit under test, holding it until the apparent leakage current becomes stable and recording the readings with adjustments for temperature. This test is especially applicable to low-capacitance units under test. Front panel of Analog Model, Cat. No. 22012470-, 120- and 160-kV DC High Voltage DC Dielectric Test Sets Time-varying tests such as the polarization index test (PI Zero-start interlock for high-voltage output test) are independent of temperature effects and save time. Pushbutton controls and indicating lights for To perform this test, a predetermined test voltage is high-voltage ON/OFF applied to the unit under test and readings are taken at 1 minute and 10 minutes. The resulting ratio is analyzed to Full circuit-breaker protection against internal damage determine insulation quality. This type of test is especially by overloads, surges or test sample breakdown appropriate for high-capacitance samples. Connection for external permissive and safety interlocks The step-voltage test is independent of temperature effects Model Capabilities/Applications and saves time. To perform this test, the output voltage is Following are the acceptance and maintenance increased in even steps at regular intervals over a fixed testing capabilities of each of the dc dielectric test period of time. As long as the resistance of the unit under sets. test increases with time, it has high-quality insulation. This type of test is only useful for high-capacitance samples. 70-kV DC Dielectric Test Set Acceptance testing on 15 kV class cable FEATURES AND BENEFITS Maintenance testing on 28 kV class cable Operates Like a Full-Wave Rectified Unit 120-kV DC Dielectric Test Set (Filtered Half-Wave Rectification) Provides the advanced performance equal to a Acceptance testing on 35 kV class cable full-wave rectified unit. Maintenance testing on 46 kV class cable Allows for a simple circuit scheme for long-term 160-kV DC Dielectric Test Set reliability. Acceptance testing on 46 kV class cable Lightweight High-Voltage Module Maintenance testing on 115 kV class cable Air insulated, it is the lightest weight module available for its voltage and power ratings. SPECIFICATIONS Convenient portability allows a single operator to transport it into the field. Input Power Nominal 120 Vac, 50/60 Hz Complete Internal Guard Circuit/Guard For 220/240 Vac, 50/60-Hz operation, add 47 to Cat. No. Connection on High-Voltage Output Cable Please note that specifications for the 47 models differ as follows: Intercepts stray surface leakage currents which could Output Current: 220/240 Vac interfere with the measurement. 120 kV Models: 5 mA for 5 min 2 mA continuous Eliminates the need for an extra lead to hook up the 160 kV Models: 5 mA for 5 min 1.5 mA continuous guard connection. When using external 240/120-volt step-down voltage transformers, the ratings may be used as given for 120 volt input. Ensures highly accurate measurements. Weight: Add approx 2 lb (1 kg) for 47 control unit. Choice of Digital or Analog Metering Ammeter (Digital Models) Ranges: The preferred medium may be selected by the user. 0 to 19.9 A Continuously Variable Test Voltage 0 to 199 A 0 to 1.99 mA User can set test voltage to intermediate values 0 to 5 mA as required. Resolution: To 0.1 A on lowest range Accuracy: 2% of reading + 1 digit Fast Charging of High-Capacitance Samples Saves the operator test time. Ammeter (Analog Models) Ranges: Negative Polarity to Ground 0 to 5 A Applies a worst-case condition to assure reliability. 0 to 50 A 0 to 500 mA Strip Chart Recorder (Optionally Available) 0 to 5 mA Provides a permanent record of the leakage current for Resolution: To 0.1 A on lowest range Accuracy: 2% of full scale range the unit under test. Voltmeter (Digital Models) Standard Safety Features Resolution: To 100 V over entire range Bipolar ammeter that displays the magnitude of Accuracy: (2% of reading + 100 V) the discharge current from the unit under test (digital Voltmeter (Analog Models) models only) Resolution Dual Range: Input-supply-line circuit breaker 35 kV/70 kV: 2.5% full scale 60 kV/120 kV: 1.6% full scale Output current overload relay 80 kV/160 kV: 2.5% full scale Accuracy: 2% of full scale range