The main products

Spare parts spare parts, the DCS control system of PLC system and the robot system spare parts,

Brand advantage: Allen Bradley, BentlyNevada, ABB, Emerson Ovation, Honeywell DCS, Rockwell ICS Triplex, FOXBORO, Schneider PLC, GE Fanuc, Motorola, HIMA, TRICONEX, Prosoft etc. Various kinds of imported industrial parts

Products are widely used in metallurgy, petroleum, glass, aluminum manufacturing, petrochemical industry, coal mine, papermaking, printing, textile printing and dyeing, machinery, electronics, automobile manufacturing, tobacco, plastics machinery, electric power, water conservancy, water treatment/environmental protection, municipal engineering, boiler heating, energy, power transmission and distribution and so on.

UNITROL 1020 UNS0119A-Z,V1 3BHE030579R0003 Excitation module

detector is used as for (a.) and (b.) above, but it is here not mounted on a heat sink but at the unit’s housing in the upper intake air zone. The detector thus measures the power section’s radiated heat and any changes in the cooling air temperature and volume. Since the cooling air volume can only be detected indirectly, a differential-pressure switch has been additionally fitted at the unit’s housing. The resistance change proportional to the temperature is acquired and evaluated in the unit’s software. If the temperature rises above the parameterized value, then first an alarm will be outputted, and - if the temperature continues to rise - an error message. The value to be set for this parameter must not be more than 10 degrees above the permissible ambient temperature. The differential-pressure switch compares the pressure inside the unit with the normal atmospheric pressure. If the fan has been switched on and the unit door closed (and no unit casings have been removed), the pressure switch will signal “Cooling conditions ok”, which means the drive may be enabled. There is no need to set any specific differential pressure (recommendation: centre setting).

Remarks on the table • The values stated are “worst case”, i.e. the values obtained under the most unfavourable conditions. • The losses of the unit electronics can be assumed to be PV-C = 30 ... 60 W, dependent on the loading involved (SDCS-COMx, number of binary inputs to “1-signal”, pulse encoder used, etc.).

Monitoring the DCS 500 power section

a.The power sections of sizes C1 and C2 are monitored by an electrically isolated PTC thermistor detector, which is installed on the likewise electrically isolated heat sink near the thyristors. The resistance change proportional to the temperature is acquired and evaluated in the unit’s software. If the temperature rises above a certain value predefined by the unit coding involved, then first an alarm will be outputted, and - if the temperature continues to rise - an error message. This means that changes in the rated cooling conditions, such as cooling air volume and temperature, the fan itself, overload due to an excessively high load current, etc. are detected. b.The size-C3 power section is likewise monitored by an electrically isolated PTC thermistor detector, which is installed on the non-isolated heat sink in an isolated configuration by means of an adaptor plate and an isolating disk. Evaluation of the resistance and the protection effect correspond to those mentioned for point (a.) above. c. The size-C4 power section is not directly monitored by an electrically isolated PTC thermistor detector. For this size, the same thermistor

Memory circuits and the back-up

 The program including system and parameter values is stored at Flash PROMs D33 and D34. Different programs can be downloaded directly to these PROMs. Application functionallity and parameter values are saved in the Flash PROM D35. Fault and Alarm messages are stored in static RAM circuits. They have a back up capacitor of 1 F, which lasts minimum 8 hours, typically several days. It takes about 30 minutes to charge the backup capacitor. ASIC function ASIC = Application Specific Integrated Circuit Most of the measurements and control functions for the DCS500 are done in the ASIC: - communication with control panel (RS 485) - communication with field exciters (RS 485) - measurement - watchdog function - A/D and D/A-conversion control - thyristor firing pulse generation