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Showing results: 6646 - 6648 of 6648 items found.

  • Three-Phase Transformer Winding Resistance Meters

    TWA Standard Series - IBEKO Power AB

    When it comes to winding resistance measurement on three-phase power transformers and autotransformers, TWA Standard series offers some of the most technically advanced instruments with LCD display in the market. Both models are capable of testing six transformer windings with a one-time cable connection, as well as three-phase automatic transformer demagnetization. The stored magnetic energy is safely automatically discharged at the end of the test. The built-in tap changer control unit enables automated test mode, where the instrument operates the tap changer without operator input and records winding resistance results based on pre-selected stabilization criteria. This option makes the operator’s job significantly easier.Both models can output test currents from 5 mA to 25 A DC for the purpose of winding resistance measurement. TWA40D has a special test mode for checking the synchronization of on-load tap changers with three phases simultaneously tested in parallel, in which the total test current can rise to up to 40 A DC.TWA40D has additional advantages when it comes to non-intrusive tap changer analysis. The unique DVtest method enables checking the moving contacts of on-load tap changers during the transition, measuring the transition time, detecting open circuits, and many other types of faults. It is performed with 0.1 ms sampling rate, simultaneously with the measurement of tap changer motor current which helps with the detection of motor and mechanical issues. A special proprietary algorithm is used for testing tap changers connected through a built-in series (booster) transformer. The DVtest can be performed either on one phase or on three phases simultaneously. It can also be performed as an additional test simultaneously with the winding resistance test in all tap positions.An additional unique advantage of TWA40D is the capability of simultaneously testing the winding resistance of all three phases of a three-phase transformer (connected in a YN configuration). This can significantly shorten the total testing time – for example, it enables the operator to perform 33 measurements instead of 99 on a tap changer with 33 tap positions.The test leads for TWA three-phase transformer winding ohmmeters are interchangeable with the TRT turns ratio testers, which means that both sets of tests can be performed with a single test lead connection to the power transformer terminals.

  • Natural Cooling Input 380VAC 3 Phase to Output 190-300VDC 10A-40A Rectifier Battery Charger

    SD230D20ZZ - Zhejiang Sandi Electric Co., Ltd

    SANDI “SD” series intelligent high-frequency switch power supply modules are specially developed to meet the demands of modern DC system. The charger rectifiers are designed with world leading patent technology “resonant voltage type soft switching power supply technology”. They feature high efficiency and stability, intelligent control, small size and light weight. Standard RS-485 interface, easy to connect with automation system. “Four remotes” functions, intelligent management. The products are widely used in power plant, substations and etc..Main characteristic of the moduleModularization design, realize N+1 backup;The friendly man-machine interface. Large screen to show, realize man-machine dialogue operate really.RS-485 inrerface, realize “4 remote” function with monitor machine.High efficiency, Nearly 95%-96%;Lightly, 230V/10A natural cooling module only 9kg;Little volume, 230V/10A natural cooling module dimension only 325mm×230mm×130mm;After the full bridge rectifying circuit rectifies 3-phase AC to DC, then adjusted by reactive PFC, power factor>0.94;Function against reverse pour: each module has been added diode against reverse pour at output terminal.LED digital screen, digital calibrate, stable current ,fault alarm Main characteristic of the ModulesThe friendly man-machine interface. LED digital screen, digital calibrate, stable current ,fault alarmHigh efficiency, up to 95%-96%;Light weight, Small sizeAfter the full bridge rectifying circuit rectifies 3-phase AC to DC, then adjusted by reactive PFC, power factor>0.94;Unequal current ratio of parallel connection<+/-3%, can ensure twenty modules work well by parallel connection.Multiple protections including over/under voltage, current limiting, short-circuit, parallel protection, over-temperature protection.Output over-voltage protectionTo prevent the disastrous accident caused by output overvoltage, there is overvoltage protection circuit in the module. Once the output voltage is higher than the threshold, the module locks up automatically and fault indication light is on, the faulty module quits work automatically and doesn’t affect the normal operation of the entire system.Output current limiting protectThe output current cannot increase infinitely. The maximum value of the output current of each module is limited to the rated output current 105%, in this range, the output current value of the module is continuously adjustable. If the load output of the module, the module will play down the output voltage.Output short-circuit protectionWhen short circuit, the output voltage drops to 0 immediately. Limit the short circuit current under 15% of rated output current. The module will not be damaged under short circuit state for a time, and resumes to work automatically after debugging. Module parallel protectionThere is parallel protection circuit in each module to ensure that when the fault module quits the system, the normal work of other modules and the system won’t be effect.Output over-current protectionThe output current cannot increase infinitely. If overloaded, the output voltage decreases automatically to protect the power components. The over current protection can be resumed automatically.

  • 40kw High Efficiency AC/DC Power Supply Charger 100-750VDC Charging Rectifier 100A Battery Charger

    SD750100G - Zhejiang Sandi Electric Co., Ltd

    40kw High Efficiency AC/DC Power Supply Charger 100-750VDC Charging Rectifier 100A Battery Charger is for DC battery system charging station. With three-phase non neutral conductor AC input, it has the advantages of high efficiency, high power density and low harmonic. 50-500Vdc output voltage range optional, suitable for all types of batteries.FeaturesProduct Introduction:SAND AC/DC Charger is specially developed for DC chargers module. It has high efficiency, high power factor, high power density, high reliability advantage. AC input 3 phase or single phase, DC output voltage range from 100 to 750VDC can be set, compliant with CE safety requirements, EMC standard EN61000-6-3 and EN61000-6-1 Class A, it is an advanced international level charger module.Unique function:● High efficiency over the full load range, full load efficiency greater than 95.5%● Wide output voltage range, 100-750VDC, suitable for a wide range of Lithium and lead acid battery● 5-inch LCD touch screen, easy to operate● Flexible application, charging voltage, charging current, charging time, timing charging can be set by LCD screen, easy to operateMain features:● Powerful protection, overheating, short circuit, overload, overvoltage, undervoltage, etc.● Three phase active power factor correction technology, reduces the harmonic interference to the grid● Dual DSP design, achieve the full digital control, less components means high reliability● Wide input voltage range, allows operation in most poor grid conditions● Soft start charging and soft shutdown minimize the impact on the battery.● Input, output have protective circuit breaker switch● Module adopts hot pluggable design, which is convenient for maintenance.● CAN/RS485 interface (Optional)SpecificationModel SD750100GAC input Input system Three phases + PEVoltage range 280Vac ~500VacRated voltage 440VacFrequency range 50Hz/60HzMaximum current <74AITHD (total harmonic distortion) <5%DC output Output power 40KWVoltage range 50-750Vdc ( can set)Constant power output voltage range 400Vdc-750VdcOutput current range (A) 100A ( 1~100A can set)Output current limit 1-100A continuously adjustableSteady voltage precision <±0.5%Steady current precision ≤±1% (rated range of 20% ~ 100% for output load)Load regulation rate ≤±0.5%Startup overshoot ≤±3%Peak-to-peak value noise ≤1% (200~1000V, 0~20MHz)Display Indication Light Green LED: normal operation,Yellow LED: alarm, Red LED: failureDisplay language EnglishDisplay 5’ LCD touch screenPower factor and THD Power factor ≥0.90 Full-load output power of @20%~50%≥0.98 Full-load output power of @50%~100%≥0.99 Full-load output power, input nominal voltage and frequency of @100%THD ≤5% Full-load output power of @50%~100%Protection function input overvoltage Protection Over Under Voltage automatic shutdown and restart when voltage return normalOutput overvoltage protection Over Under Voltage automatic shutdown and restart when voltage return normalOver-temperature protection Automatic shutdown. Automatic restart when the temperature return to normalShort circuit protection Automatic shutdown and lock, need power off to restart to unlockEfficiency Under Rated input voltage ≥95.2%

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