ENGLISH User manual © Copyright HT ITALIA 2010 Release EN 1.
HT78 Table of contents: 1. SAFETY PRECAUTIONS AND PROCEDURES ..........................................................2 1.1. 1.2. 1.3. 1.4. 2. GENERAL DESCRIPTION ...........................................................................................4 2.1. 2.2. 3. TRMS and MEAN VALUE measuring instruments............................................................ 4 TRUE ROOT MEAN SQUARE VALUE and CREST FACTOR definitions........................ 4 PREPARATION FOR USE .............................
HT78 1. SAFETY PRECAUTIONS AND PROCEDURES This meter complies with IEC/EN61010-1. For your own safety and in order to avoid damaging the instrument, you’re recommended to keep to the instructions contained in this manual and read carefully all the notes preceded by the symbol . Take extreme care for the following conditions while measuring: • Do not measure voltage or current in humid or wet environment.
HT78 1.2. BEFORE USE Always keep to the instructions contained in this manual: CAUTION Non compliance with the warnings and/or the instructions may damage the tester and/or its components or injure the operator.
HT78 2. GENERAL DESCRIPTION HT78 meter can performs the herewith features: • • • • AC TRMS current measurement up to 3000A AC leakage current measurement with 0.1mA resolution DC voltage analogical output for connection with external data loggers 150Hz low-pass filter for reduce harmonic components of input signal Each feature can be selected by using rotation selector on meter’s front panel. The Data HOLD, FILTER and LOCK functions are still available (see § 4.2).
HT78 3. PREPARATION FOR USE 3.1. INITIAL The meter has been checked from a mechanical and electrical point of view before shipment. Every care has been taken to make sure that the instrument reaches you in perfect conditions. However, it’s advisable to make a rapid check in order to detect eventual damages which may have occurred in transit. Should this be the case, enter immediately the usual claims with the carrier. Make sure that all the accessories listed in § 6.3.1 are contained in the package.
HT78 4. OPERATING INSTRUCTIONS 4.1. INSTRUMENT DESCRIPTION 4.1.1. Front panel LEGEND: 1. 2. 3. 4. 5. 6. 7. 8. 9. Fig.
HT78 4.2. DESCRIPTION OF PARTS 4.2.1. Range and ON/OFF selector Rotate the function selector from “OFF” position to any other position to turn on the meter. Rotate again the selector to “OFF” position to switch off the meter 4.2.2. D-H key Press D-HOLD key to enable Data HOLD feature. The “DH” message is shown and the measured value is frozen on the display. Press the same key to exit from the function. 4.2.3.
HT78 4.2.6. DC analogical output The meter is designed with a DC voltage analogical output depending on the measured current value and can be used for connection with external data loggers, digital multimeters, etc.. (see Fig. 2) by using customized cables CAUTION Do not apply any vltage to the DCV output of metere durino the recording operation Fig. 2: Connection of meter with external logger 1.
HT78 4.3. HOW TO PERFORM THE MEASUREMENTS 4.3.1. AC Current measurement CAUTION Do not perform any AC current measurement on circuit with nominal voltage higher to 500V to round to avoid possible electrical shocks and to damage the meter Fig. 3: Taking AC current measurement 1. Select a measurement range among the 3A, 30A, 300A or 3000A options 2. Move the FILTER selector on ON position to activate the “Low-pass 150Hz filter” (see § 4.2.3) 3.
HT78 4.3.2. Leakage current measurement on Single phase system CAUTION Do not perform any AC current measurement on circuit with nominal voltage higher to 500V to round to avoid possible electrical shocks and to damage the meter Fig. 4: Taking leakage current measurement on Single phase systems 1. Select the 300mA range on the meter 2. Move the FILTER selector on ON position to activate the “Low-pass 150Hz filter” (see § 4.2.3) 3.
HT78 4.3.3. Leakage current measurement on Three phase system CAUTION Do not perform any AC current measurement on circuit with nominal voltage higher to 500V to round to avoid possible electrical shocks and to damage the meter Fig. 5: Taking leakage current measurement on Three phase systems 1. Select the 300mA range on the meter 2. Move the FILTER selector on ON position to activate the “Low-pass 150Hz filter” (see § 4.2.3) 3.
HT78 5. MAINTENANCE 5.1. GENERAL INFORMATIONS 1. This clamp is an accured instrument. Whether in use or in storage, please do not exceed the specification requirements to avoid possible damages or dangers. 2. Do not place this meter at high temperatures or humidity or expose it to direct sunlight. 3. Be sure to turn off the meter after use. If you expect not to use the tester for a long time, remove the battery in order to avoid leakages of battery liquid that would damage the internal parts. 5.2.
HT78 6. TECHNICAL SPECIFICATIONS 6.1. CHARACTERISTICS Accuracy is indicated as [% rdg + (number of dgt) * resolution] referred to: 23°C(73°F) ± 5°C(41°F); RH< 80% AC TRMS Current Range 300mA 3A 30A 300A 3000A Resolution 0.1mA 0.001A 0.01A 0.1A 1A Accuracy Bandwidht ±(1.5%rdg+ 8dgt) 50 ÷60Hz Max input current 3Arms 30Arms 300Arms 3000Arms ±(2.0%rdg+ 8dgt) DC analogical output Range 300mA 3A 30A 300A 3000A Resolution 1mV/1mA 1mV/0.01A 1mV/0.1A 1mV/1A 1mV/10A Accuracy Bandwidht ±(1.
HT78 6.2. ENVIRONMENTAL CONDITIONS 6.2.1. Climatic conditions Reference temperature: 23 ± 5°C ; (73°F± 41°F) Operating temperature: 0 ÷ 40°C ; (32°F ÷ 104°F) Operating humidity: <80%RH Storage temperature: -10 ÷ 60°C ; (-44°F ÷ 140°F) Storage humidity: < 80%RH This product conforms to the prescriptions of the European directive on low voltage 2006/95/EEC (LVD) and to EMC directive 2004/108/EEC 6.3. ACCESSORIES 6.3.1.
HT78 7. SERVICE 7.1. WARRANTY CONDITIONS This equipment is guaranteed against material faults or production defects, in accordance with the general sales conditions. During the warranty period (one year), faulty parts may be replaced. The manufacturer reserves the right to decide either to repair or replace the product. In case of returning of the instrument, all transport charges must be paid by the customer.
