Telwin Practica 152 Manuel D'instructions page 6

2. INTRODUCTION AND GENERAL DESCRIPTION
This apparatus is a power source for arc welding, made specifically for
alternating current (AC) MMA welding with coated electrodes.
STANDARD ACCESSORIES:
- electrode holder clamp;
- return cable and earth clamp.
3. TECHNICAL DATA
DATA PLATE
The most important data regarding use and performance of the welding
machine are summarised on the rating plate and have the following
meaning:
1- Protection rating of the covering.
2- Symbol for power supply line:
1~: single phase alternating voltage.
3- Symbol for welding procedure provided.
4- Symbol for internal structure of the welding machine.
5- EUROPEAN standard of reference, for safety and construction of arc
welding machines.
6- Manufacturer's serial number for welding machine identification
(indispensable for technical assistance, requesting spare parts,
discovering product origin).
7- Symbol S: indicates that welding operations may be carried out in
environments with heightened risk of electric shock (e.g. very close
to large metallic volumes).
8- Performance of the welding circuit:
- U : maximum no-load voltage (open welding circuit).
0
- I /U : current and corresponding normalised voltage that the
2 2
welding machine can supply during welding.
- X : Duty cycle: indicates the time for which the welding machine
can supply the corresponding current (same column). It is
expressed as %, based on a 10 min. cycle (e.g. 60% = 6 minutes
working, 4 minutes pause, and so on).
If the usage factors (on the plate, referring to a 40°C environment)
are exceeded, the thermal safeguard will trigger (the welding
machine will remain in stand-by until its temperature returns
within the allowed limits).
- A/V-A/V : shows the range of adjustment for the welding current
(minimum-maximum) at the corresponding arc voltage.
9- Technical specifications for power supply line:
- U : Alternating voltage and power supply frequency of welding
1
machine (allowed limit ±10%):
- I : Maximum current absorbed by the line.
1 max
- I : effective current supplied.
1 eff
10- : Size of delayed action fuses to be used to protect the power
line.
11- Symbols referring to safety regulations, whose meaning is given in
chapter 1 "General safety considerations for arc welding".
Note: The data plate shown above is an example to give the meaning
of the symbols and numbers; the exact values of technical data for the
welding machine in your possession must be checked directly on the data
plate of the welding machine itself.
OTHER TECHNICAL DATA
- Performance of the welding circuit in function of the diameter of
the electrode (Fig. A-12):
- Ø : diameter of weldable electrodes.
- I : welding current at the corresponding arc voltage.
2
- tw : Average load time calculated between thermal switch reset and
interruption with welding machine at steady state.
- tr : Average reset time calculated between thermal switch
interruption and reset with welding machine at steady state.
- WELDING MACHINE: see table 1 (TAB.1)
The welding machine weight is shown in table 1 (TAB. 1).
4. DESCRIPTION OF THE WELDING MACHINE
CONTROL, ADJUSTMENT AND CONNECTION DEVICES
5. INSTALLATION
WARNING! CARRY OUT ALL INSTALLATION OPERATIONS
AND ELECTRICAL CONNECTIONS WITH THE WELDING MACHINE
COMPLETELY SWITCHED OFF AND DISCONNECTED FROM THE
Fig. A
Fig. B
POWER SUPPLY OUTLET.
THE ELECTRICAL CONNECTIONS MUST BE MADE ONLY AND
EXCLUSIVELY BY AUTHORISED OR QUALIFIED PERSONNEL.
Assembling the protective mask
POSITIONING THE WELDING MACHINE
Choose the place where the welding machine is to be installed so that
there are no obstructions to the cooling air inlets and outlets; at the same
time make sure that conductive dust, corrosive vapours, humidity etc.
cannot be drawn into the machine.
Leave at least 250 mm of free space all around the welding machine.
WARNING! Position the welding machine on a level surface
with sufficient load-bearing capacity, so that it cannot be tipped over
or shift dangerously.
CONNECTION TO THE MAIN POWER SUPPLY
- Before making any electrical connection, make sure the rating data of
the welding machine correspond to the mains voltage and frequency
available at the place of installation.
- The welding machine should only be connected to a power supply
system with the neutral conductor connected to earth.
- To ensure protection against indirect contact use residual current
devices of the following types:
- Type A ( ) for single phase machines;
- To comply with the requirements of the EN 61000-3-11 (Flicker)
standard we recommend connecting the welding machine to interface
points of the power supply that have an impedance of less than Zmax
=0.3 ohm.
- The welding machine falls within the requisites of IEC/EN 61000-3-12
standard.
Plug and outlet
Connect the power supply plug to a mains socket fitted with fuses or an
automatic circuit-breaker; the corresponding earth terminal should be
connected to the (yellow-green) earth conductor of the power supply.
Table 1 (TAB. 1) shows the recommended delayed fuse sizes, in amps, for
the main supply, which have been chosen according to the maximum
rated current output from the welding machine, and to the nominal
power supply voltage.
WARNING! Non-compliance with the above regulations
renders the manufacturer's safety system (class I) inefficient, with
resulting serious risks to people (e.g. electric shock) and things (e.g.
fire).
CONNECTION OF THE WELDING CABLES
WARNING! BEFORE
CONNECTIONS MAKE SURE THE WELDING MACHINE IS SWITCHED
OFF AND DISCONNECTED FROM THE POWER SUPPLY OUTLET.
Table 1 (TAB. 1) gives the recommended values for the welding cables
(in mm ) depending on the maximum current supplied by the welding
2
machine.
Connecting the electrode-holder clamp welding cable
On the end take a special terminal that is used to close the uncovered
part of the electrode.
For welding machines supplied with a terminal, this cable is connected to
the terminal with the symbol
Connecting the welding current return cable
This is connected to the piece being welded or to the metal bench
supporting it, as close as possible to the join being made. For welding
machines supplied with a terminal, the cable is connected to the terminal
with the symbol
Recommendations:
- Screw the welding cable connectors right down into the quick
couplings (if present), so as to ensure perfect electrical contact;
otherwise, the connectors will overheat, wear rapidly and become
inefficient.
- 6 -
Fig. C
MAKING THE
.
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FOLLOWING