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Specification
MACHINE TYPE :
It is a 3 D. C. Machine. The advantage of this system is low working
cost in terms of improved power factor, which can be of the order
of 0.9. In addition to this it gives balance load in each phase.
Also due to D.C. impendence of secondary circuit dose not come in
picture, thus the voltage drop in the system comes down resulting
in lower KVA of machine for the same application as compared to
single phase A. C. Machine.
The machine is sturdy, all welded steel plate fabrication, and
suitably welded and stiffened at points of stress to minimise deflection.
The transformer and D.C. Rectifier assembly fitted inside of the
body. The pneumatic cylinder mounted on the right hand side to give
horizontal movement of the ram guide through precision slides with
graphite heating / forging electrodes with water-pump to cool un-heated
portions. All internal parts are easily accessible.
TRANSFORMER RECTIFIER SET :
Transformer of a special type conforming to international standards
applicable to this class of Transformers. Water cooled, having core
of high grade electrical steel, primary and secondary coils of Electrolytic
copper of ample section, heavy duty class 'F' insulated and impregnated,
suitable for with-standing continuously a temperature of 155oC deg.
The direct current rectifier system consists of high power silicon
rectifier to rectify the alternating current available on the secondary
of transformer to direct current. It has large number of basic rectifier
pellets connected in between the secondary of transformer and the
output bus-bars. These pallets are clamped in specially designed
clamping system which ensures the correct amount of clamping pressure
and uniform contact. Suitable water cooling system designed into
these clamps ensures efficient cooling of rectifier elements.
CURRENT CONTROL BY TRANSFORMER TAPS :
Transformer primary coils provide with taps brought out to tap change
links for adjustment of current in steps from 55-100% Tap change
links enclosed inside the transformer cabinet.
HEAT INITIATION :
By means of operator's foot switch connected to low voltage safe
initiating switch, which operates the main Electro-magnetic contractor.
ELECTRODE CONTROL SYSTEM :
One of the two electrodes actuated via a quick follow up mechanism
by a heavy duty 2 way pneumatic cylinder, controlled by an electrically
operated solenoid air valve. Compressed air at 2-6 KSC acting on
the pneumatic cylinder provides the necessary electrode force.
Machine is provide with air filter, air lubricator, air pressure
regulating valve, pressure gauge, and all internal air connections.
ADJUSTMENT OF ELECTRODE FORCE :
By air pressure regulating valve provided on the machine.
ADJUSTMENT OF ELECTRODE STROKE :
By horizontal adjustment of the stationary electrode.
PLATENS :
Constructed from high quality copper alloy accurately machined having
T-slots to international / IS standards.
ELECTRODES :
Machine will be provided with custom designed one set of graphite
electrodes to suit one type of the job. Additional sets of electrodes
shall be supplied request at extra cost.
OPERATION :
Copper foils are wound over a mandrel and then one end pressed to
make the stracked assembly.
Copper foils these conditions are fed to the machine. The portion
to be forged (generally ends) is held on fixed electrode and clamp
foot switch is initiated. RHS moving electrode clamps the flexible
link under pressure with other end dipped in water-pump. Current
switch is initiated. The main magnetic contractor gets ON and transformer
is energised. Graphite electrodes start heating to cherry red colour
and heat gets conducted to the interior of links and raise temp.
of on-off current foot switch operation. These pulses provide a
constant heat flow from electrodes into the flexible link.
(NEVER ALLOW THE ELECTRODE TO GET BRIGHT-WHITE HOT OR ELSE ENDS
OF COPPER FOILS WILL MELT OFF).
During the operation whatever heat is conducted to other areas
of flexible link is drained off by continuous flow water in tank
by this allowing to avoid annealing of copper foils. When fully
forged force to continue till graphite electrode colour comes to
normal black. Release the clamp and link will fall in water-sump
permitting it to be cooled.
SAFETY PROVISION :
Thermoswitch on transformer.
COOLING SYSTEM :
Transformer, Platters, Electrode Holders are cooled, Internal water
cooling piping for each circuit is provided with machine. The work
piece also to be water cooled externally. A water tank (GI) is provided
with machine for external cooling of flexible link. All circuits
terminate into a sight tank provided. Customer to provide cooling
water supply of recommended flow rate free from residue forming
impurities and it temperature of less than 30.
ELECTRO-MAGNETIC CONTRACTOR :
Machine provide with electro-magnetic heavy duty contractor for
switching on/off of main transformer.
Service Requirements
MAIN SUPPLY :
415 Volts, 3 phase, 50 cycles, machine suitable for connecting to
3 lines of 3 phase supply.
MAIN SUPPLY CABLE & DISCONNECTING SWITCH
FUSE :
To be provided by the customer, size/rating as recommended. (Refer
technical data).
COMPRESSED AIR :
Customer to provide compressed air supply of recommended flow volume
at a minimum pressure of 5.68 ksc.
COOLING WATER :
Cooling water minimum at 3.1 kg/cm2 pressure and temperature below
30 at recommended flow rate to be provided by the customer.
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