Telwin PTE 18 Manuel D'instructions page 11

connections.
- Do not use the spot-welder in damp or wet environments or in the rain.
- When connecting the welding cables or carrying out any routine maintenance
operation on the arms and/or electrodes the spot-welder should be switched
off and disconnected from the power supply. Pneumatic cylinder-operated
spot-welders should be locked with the main switch in the "O" position and
the padlock closed.
The same procedure should be followed when making connections to the
water supply or to a closed circuit cooling unit (water-cooled spot-welders)
and whenever repairs are made (extraordinary maintenance).
- Do not weld on containers, receptacles or piping that contain or have
contained flammable liquid or gas products.
- Do not operate on materials cleaned with cholorinated solvents or near such
substances.
- Do not weld on pressurised containers.
- Remove all flammable substances from the work area (e.g. wood, paper, rags
etc.).
- Make sure there is sufficient ventilation or provide means for removing
welding fumes near the electrodes; a systematic approach is necessary to
evaluate limits of exposure to the welding fumes depending on their
composition and concentration and on the length of exposure.
- Always protect the eyes with suitable eye protectors.
- Wear protective gloves and clothing suitable for resistance welding work.
- Noise levels: If the personal daily exposure level (LEPd) is found to be greater
than 85db(A) due to particularly intensive welding operations, wearing
personal protection devices is compulsory.
- The strong magnetic fields generated by resistance welding processes (very
high currents) may damage or interfere with:
- CARDIAC STIMULATORS (PACE MAKERS)
- ELECTRONICALLY CONTROLLED IMPLANTED DEVICES
- METAL PROSTHESES
- Data transmission or local telephone networks
- Instrumentation
- Clocks and watches
- Magnetised cards
WEARERS OF VITAL ELECTRICAL OR ELECTRONIC DEVICES AND PEOPLE
WITH METAL PROSTHESES SHOULD NOT BE ALLOWED TO USE THE SPOT-
WELDER.
SUCH PERSONS SHOULD TAKE MEDICAL ADVICE BEFORE STOPPING IN
THE VICINITY OF SPOT -WELDERS AND/OR WELDING CABLES.
- This spot-welder complies with all requirements of the technical standard for
the product, which to be used only and exclusively in industrial environments
and for professional purposes.
Electromagnetic compatibility with a domestic environment cannot be
guaranteed.
RESIDUAL RISKS
- RISK OF UPPER LIMBS BEING CRUSHED
Both the operating method for the spot-welder and the variability in shape and
size of the piece being welded make it impossible to provide integrated
protection against the danger of the upper limbs being crushed: fingers,
hands, forearm.
The risk should be reduced by appropriate preventive measures:
- The operator should either be expert or trained in resistance welding
procedures using this type of appliance.
- There should be risk evaluation for every type of job to be done; equipment
and masking should be provided to support and guide the work-piece
(unless a portable spot-welder is used).
- Whenever the shape of the piece allows it, adjust the electrode distance so
that the stroke does not exceed 6 mm.
- Do not allow more than one person to work on the same spot-welder at the
same time.
- Unauthorised persons should not be allowed in the working area.
- Do not leave the spot-welder unattended: in such a case it should be
disconnected from the power supply; for pneumatic cylinder-operated spot
welders turn the main switch to "O" and lock it with the supplied padlock,
take out the key and leave it with the person in charge.
- RISK OF BURNS
Some parts of the spot-welder (electrodes arms and nearby areas) may
reach temperatures of over 65°C: suitable protective clothing must be worn.
- RISK OF TIPPING AND FALLING
- Place the spot-welder on a level horizontal surface that is able to support its
weight; confine the spot-welder to the support surface (when required in
the "INSTALLATION" section of this manual). Otherwise with inclined or
uneven floors or moveable supporting surfaces there is the danger of
tipping.
- Never lift the spot-welder unless explicitly required by the "INST ALLATION"
section of this handbook.
- IMPROPER USE
It is dangerous to use the spot-welder for any other purpose than that for
which it is designed (spot resistance welding).
The safeguards and moveable parts of the spot-welder casing should all be in
position before connection to the power supply.
WARNING: All manual operations on moveable accessible parts of the spot
welder, for example:
- Electrode replacement or maintenance
- Adjusting the position of the arms or electrodes
SHOULD BE CARRIED OUT WITH THE SPOT-WELDER SWITCHED OFF AND
DISCONNECTED FROM THE POWER SUPPLY (MAIN SWITCH LOCKED TO "O"
USING PADLOCK WITH KEY TAKEN OUT for PNEUMATIC CYLINDER-operated
models).
2. INTRODUCTION AND GENERAL DESCRIPTION
2.1 INTRODUCTION
Column spot welders with downward curvilinear electrode for resistance welding
(single spot).
Electronic power control (thyristors) integrated with timer and start current limiter.
Thermal safeguard with indicators (overload or cooling water failure).
Operation:
- "PTE" models: mechanical, equipped with pedal with adjustable lever length;
- "PCP" models: pneumatic, equipped with double effect cylinder controlled by a
pedal valve; operation shutdown due to power failure and/or compressed air failure.
2.2 OPTIONAL ACCESSORIES
- Arm pair, length 500mm, complete with electrode holders and standard electrodes.
- Arm pair, length 700mm, complete with electrode holders and standard electrodes.
- Curved electrodes.
- Closed circuit water cooling system (suitable for PTE or PCP 18 only).
3. TECHNICAL DATA
3.1 RATING PLATE (FIG.A)
The main data relating to use and performance of the spot-welder are summarised on
the rating plate and have the following meanings:
1- Number of phases and frequency of power supply.
2- Power supply voltage.
3- Rated mains power with 50% duty cycle.
4- Maximum mains power when spot-welding.
5- Maximum loadless voltage over electrodes.
6 - Maximum current when electrodes are shorted.
7- Gauge and length of arms (standard).
8- Minimum and maximum adjustable electrode force and corresponding
compressed air supply pressure.
9- Cooling water flow rate.
10- Safety symbols, the meanings of which are given in chapter 1 "General safety rules
for resistance welding".
Note: The rating plate shown is an example to show the meaning of the symbols and
numbers; the exact technical specifications of your spot-welder can be found on the
rating plate of the spot-welder itself.
3.2 OTHER TECHNICAL DATA (FIG.B)
4. DESCRIPTION OF THE SPOT-WELDER
4.1 SPOT-WELDER ASSEMBLY AND DIMENSIONS (FIG. C)
4.2 CONTROL AND ADJUSTMENT DEVICES
4.2.1 Control panel (FIG. D1)
1- General switch (in PCP models with emergency stop functions and possibility of
padlock in "O" position: padlock and keys supplied).
2- Indicator LED's:
a) (green) machine powered, control board "ON",
b) (green) welding "ON" (control and thyristor model activated),
c) (yellow) thermal safeguard triggered: welding disabled (in PCP models
arm operation is also disabled).
3- "POWER" : welding current adjustment potentiometer;
4- "TIMER" : welding time adjustment potentiometer;
5- start-up/reset push-button (PCP models);
/
6- pressure only (machine does not weld) / welding device selector (PCP
models only).
4.2.2 Compression nut (FIG. D2)
This can be reached by opening the gate on the rear of the spot-welder; it is used to
regulate the force exerted by the electrodes by adjusting the pre-load of the spring.
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