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8. Faults 9. Dismounting, return and disposal Appendix 1: Accuracy of the dew point Appendix 2: EC declaration of conformity, model GDT-20 Appendix 3: EC declaration of conformity, model GDHT-20 46 Declarations of conformity can be found online at www.wika.com...
Modbus protocol via the RS-485 interface. The model GDT-20 or GDHT-20 transmitters are therefore used for permanently monitoring the stated status parameters in SF gas tanks. The instrument has been designed and built solely for the intended use described here, and may only be used accordingly.
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CIGRE report 276, 2005 (Practical SF gas handling instructions) ■ Leaks during operation: IEC 60376 (new SF gas, technical SF gas) ■ IEC 60480 (used SF gas) ■ CIGRE 2002 (“SF gas in the electrical industry”) ■ WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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Made in Germany www.wika.com Pin assignment Explanation of symbols Before mounting and commissioning the instrument, ensure you read the operating instructions! CE, Communauté Européenne Instruments bearing this mark comply with the relevant European directives. WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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2004/108/EC, EN 61326 emission (group 1, class B) and interference immunity (industrial application) EMC tests Interference immunity per IEC 61000-4-3: 30 V/m (80 MHz ... 2.7 GHz) ■ Burst per IEC 61000-4-4: 4 kV ■ ESD per IEC 61000-4-2: 8 kV/15 kV, contact/air ■ WIKA operating instructions transmitter, models GDT-20, GDHT-20...
3../ 4. Design and function / 5. Transport, packaging and ... Impulse voltages per IEC 61000-4-5: ■ GDT-20: 2 kV conductor to ground, 1 kV conductor to conductor GDT-20: 1 kV conductor to ground, 1 kV conductor to conductor ■...
(depending on the particular application, this may take several days). The measuring point should preferably be positioned directly at the gas compart- ment. Measurement at the end of measuring lines prevents optimal results WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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Make sure that no moisture enters at the cable end. ■ 6.2.2 Pin assignment Circular connector M12 x 1 (5-pin) Reference potential RS-485 common Voltage supply Ground Signal RS-485 Signal RS-485 WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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6.3 Modbus The Modbus communication protocol is based on a master/slave architecture. The protocol ® implemented in the transmitters GDT-20 and GDHT-20 is Modbus RTU with serial transmis- ® sion via a 2-wire RS-485 interface. The Modbus protocol is a single-master protocol. This master controls the entire data and ®...
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With these settings, the transmitters can be read via the button “download from device”. Factory setting Tag number: WIKA ■ Address: 247 ■ Baud rate: 19,200 ■ Parity: none ■ ■ Gas mixture SF [%]: 100 % ■ Gas mixture partner: N2 ■ WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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English (USA), since other- wise, communication problems might occur. 6.4.2.3 Data logger The data logger is used for recording measured values over a certain time span. WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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Write single register Write multiple registers Writing of one or more register values or the instrument Diagnostic - Sub code 00 Diagnostic function Writing or reading of one/several register values or the instru- WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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Humidity, dew point °C Tank pressure 00040 Humidity content based on volume 00042 Humidity content based on weight 00044 Humidity content based on volume 00046 Humidity content based on weight 00048 Relative humidity WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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The available address space is 1 ... 247 (247 standard) Baud rate Baud rate Register value 1,200 2,400 4,800 9,600 14,400 19,200 5 (standard) 38,400 57,600 115,200 Parity Parity Register value None 0 (standard) Even WIKA operating instructions transmitter, models GDT-20, GDHT-20...
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Software reset Writing 0x0001 00203 Reset to standard Writing 0x0001 00204 Start heating process (only GDHT-20) Writing 0x0001 After a restart (voltage supply was interrupted), the error memory is reset. Writing 0x0001 in WIKA operating instructions transmitter, models GDT-20, GDHT-20...
For shorter intervals, the register has to be written manually, the shortest possible interval is 10 minutes. 7. Maintenance and cleaning 7.1 Maintenance The transmitters are maintenance-free. Repairs must only be carried out by the manufacturer. WIKA operating instructions transmitter, models GDT-20, GDHT-20...
In this case, contact the manufacturer. If a return is needed, please follow the instructions given in chapter 9.2 “Return”. WIKA operating instructions transmitter, models GDT-20, GDHT-20...
WARNING! Strictly observe the following when shipping the instrument: All instruments delivered to WIKA must be free from any kind of hazardous substances (acids, bases, solutions, etc.). When returning the instrument, use the original packaging or a suitable transport package.
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