LVMS Low-Voltage Making Switch

Transcription

1 CESI LVMS Low-Voltage Making Switch

2 SUMMARY 1 GENERAL REFERENCES TECHNICAL SHEET... 5 CESI Via R. Rubattino 54 Capitale sociale Euro Registro Imprese di Milano Centro Elettrotecnico Milano - Italia interamente versato Sezione Ordinaria Sperimentale Italiano Telefono Codice fiscale e numero N. R.E.A Giacinto Motta SpA Fax iscrizione CCIAA P.I. IT

3 Brochure CESI Page 3/5 1 GENERAL The CESI LVMS making switch has been designed to make and withstand the low voltage short circuit current within its specifications and to open the test circuit when no more current flows. It has to allow the making operation with high speed combined with high reliability and accuracy. Furthermore, its contacts must bear each time the test currents, which are, in this case, mainly at the short-circuit level of the various test apparatuses, and the relevant electrodynamic stress. The making switch is an essential device for a short-circuit LV laboratory, but the market does not provide any standard solution meeting the requested performances. The CESI LVMS making switch has been developed as a consequence of the experience based on more than 20 years' shortcircuit testing in the low voltage field and, owing to that, possesses all the desired characteristics. The LVMS is a three-pole air switch, operated by a single hydraulic device driving simultaneously the three poles. It has a closing time of about 30 ms, and uncertainty between subsequent operations not exceeding 300 µs. This performance is obtained through the adoption of springs pre-charged by a special hydraulic device associated with a power control circuit. The CESI making switch is composed by the following elements: a structure with fixed contacts supporting a hydraulic piston operating the mobile contacts, assembled on a base frame fitted with shock absorbers; a control cabinet housing the hydraulic and control circuits and an electronic device amplifying the synchronised tripping command, to supply the closing pulse with the appropriate power; the oil pipes connecting the cabinet to the hydraulic piston of the making switch. The high current terminals of the LVMS must be connected to the test circuit by means of appropriate flexible copper connections. The power control circuit must be activated by a synchronised triggering command supplied by the remote laboratory test sequencer. The equipment is subjected to the following tests at CESI laboratories: dielectric tests short-circuit making tests short-time current test mechanical operation tests. The LVMS shall be accompanied by the following documents: user's guide CESI acceptance test report.

4 Brochure CESI Page 4/5 2 REFERENCES Several samples of the CESI LVMS have been produced by CESI; some of them have been in operation since years in international laboratories: Short-circuit current [ka] Client Country Year Quantity 150 CESI-Milan Italy CESI-Milan Italy CFE-Irapuato Mexico CPRI-Bhopal India PLN LMK-Jakarta Indonesia Labein-Bilbao Spain Tertec-Taipei Taiwan LPEE-Casablanca Morocco Bogazici University Turkey Figure 1 - LVMS and control board

5 Brochure CESI Page 5/5 3 TECHNICAL SHEET Reference standards RATING Operating voltage Power-frequency insulation level Short-circuit current Short-circuit duration Short-circuit making current Frequency Auxiliary voltages IEC IEC V 2000 V 100 ka or 150 ka 1 s ON 30 min OFF 250 ka or 375 ka Hz V 3φ PERFORMANCE CHARACTERISTICS Operating temperatures +10 to +40 C Relative humidity (not condensing) 40 to 95% Installation Indoor Closing duration about 30 ms Closing duration uncertainty (confidence level 95%) < 300 µs Pole closing discrepancy < 500 µs CONSTRUCTION CHARACTERISTICS Typical configuration CESI 10008/33 Assembly drawings CESI 10008/1-2-3 Number of poles 3 Number of operating devices one (three-pole) Degree of protection IP 21 Max vertical thrust during closing operation: < 5000 kg for 10 ms Dimensions (approximate): Making switch 892x900x1350 mm Control cabinet 1000x600x1800 mm Mass (approximate): Making switch about 718 kg Control cabinet about 356 kg RELEASE POWER UNIT Power supply Hz - Fuse 1A Start input 12 V - 50 ma or closing contact Gate input 12 V - 50 ma or closing contact Output pulse 180 Vdc Recording output 12V-10 ma (from optodecoupler) Delay from start 20 µs Jitter 10 µs SPARE PARTS Set of washers for the hydraulic jack no. 1 Single-phase set of moving contacts no. 1 Single-phase set of fixed contacts. no. 1