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Rectifier Units
These Rectifier units are suitable for all electro deposition processes within their rating. The widest applications in the field require maximum voltage of 8V, 12V and 20V D.C. at various current capacities as per requirement. A range of current ratings from 100 amps to 10000 amps is covered in our regular manufacture. Our standard sizes are listed in the price list issued separately.
Brief Specification
Input Voltage
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360 to 440V A.C.
3 Phase 50 Hz
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Out Voltage
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Continuously variable from zero to the full rated D.C. voltage
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Output Current
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Rated maximum D.C. Current
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Efficiency
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Not less than 75%
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Temperature Rise
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Less than 45oC above ambient at the top of the oil
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Class of Insulation
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'A'
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A.C Input 'AE' Electroplating Rectifier units are designed for three phase, 50Hz. AC input supply and are suitable for operation at any voltage between 360 to 440 voltas. Thus, it covers a wider range to center for mains voltage fluctuations. The input to the unit is to be connected through a switchfuse unit of proper rating, which is not included in the scope of the supply and has to be procured separately.
D.C. Input The D.C. output is continuously and steplessly variable from zero to the full rated voltage for any input voltage between 360 to 440 volts and for any load between zero to its rated full load. The ripple content in the output is very low (approximately 5%) and as such these units are very much suitable for all special processes such as chrome plating or hard chrome plating where low ripple content is necessary.
Circuit and Components The circuit employed in this rectifier units is simple and universal. Supply is given to Dimmerstat continuously variable voltage auto transformer, which in turn supplies a variable to the primary of a three phase double wound Delta / Double star connected transformer through H.R.C. fuses. The secondary of the transformer is connected to Hexa-phase connected rectifier using Silicon Diodes. The output is obtained from the rectifier and the star points of the transformer through and interphase transformer. Moving Coil voltmeter and ammeter with shunt are provided to measure the output voltage and output current.
- Dimmerstat
Output is an important factor in Electrodeposition processes. 'AE' provide a stepless and continuous variation of output voltage, which is a far superior method to other methods of control like resistance boards, tap switches etc. The stepless variation is achieved with the help of 'Dimerstat' which is Registered Trade name for Continuously Variable Voltage Auto Transformer manufactured by 'AE'. Unlike other methods of output control, Dimmerstat provides a stepless, on-load and without break variation of output Voltage, without any loss of power. It being one of our own standard product, availability of spares or replacement is guaranteed, although the necessity is very rare.
- H.R.C. Fuses
Overloading or short circuiting is not a rare occasion in Electrode position processes. Special High Rupturing Capacity (H.R.C.) fuses are therefore provided on the primary of the Main transformer. These fuses will blow only when there is overload or short circuit on the output or if there is an internal short circuit and in such cases they should be replaced by H.R.C. fuses of the same rating only.
- Double Wound Transformer
Tis is of conventional design and conforms to standard specifications of BS : 171 or IS : 2026 as regards the temperature rise and insulation are concerned. The primary is delta connected and secondary has two star connected windings.
- Interphase Transformer
Connected between two star points of the secondary of the main transformer, the Interphase transformer improves communication thereby increasing the rating of the Rectifier.
- Rectifier
This is made up of sturdy liberally rated Silicon diodes and are arranged in a six phase circuit. The diodes are mounted on cooling fans so as to dissipate the heat thereby increasing the rating of the diode. Depending upon the output current rating, necessary number of diodes are connected in parallel.
- Metering
A Voltmeter and an Ammeter are provided on a separate panel to indicate the output voltage and output current. The panel is mounted on one of the tanks to enable easy manipulation with the help of the Dimmerstat. The ammeter is used in conjunction with an external shunt, which is fitted inside the tank. The voltmeter, ammeter and the shunt are all manufactured by ourselves and are therefore obviously backed by 'AE's well-known after sales service. Rectifier units upto an output capacity of 12KW are provided with 4" dial moving coil flush type meters. For units of higher capacities the meters are of 6" size.
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