Spot Welding; Aluminium Welding; Preparation For Welding - Helvi MONOMIG 186 Manuel D'instructions

Main ON/Off switch
1.
This green led lights up when the machine is switched on. If this switch is yellow, it won't light
up when you switch on the welder. In this case the switch functions also as overtemperature pilot
lamp; it will light up if the thermostatic protection will cut off the machine and will automatically
extinguish after the machine has cooled sufficiently.
Voltage selector switch / commutator
2.
It can be a 6 or 8 position rotary switch. With this switch you can adjust the welding voltage ac-
cording to the wire feed speed and wire diameter. The 3 position rotary switch is completed by a
Min/Max switch. Through the different combinations you can obtain 6 voltage levels.
3. Wire speed
To increase the wire speed, turn the potentiometer clockwise; to decrease the wire speed, turn it
counter-clockwise.
Timer for spot welding (0,2-3s) (only on some models)
4.
This potentiometer permits the adjustment of the spot welding time;
B.B.T. (Burn Back Time)
5.
When releasing the torch trigger the machine will work for a very short time. This function allows
avoiding the burning of the wire and the consequent sticking of this to the contact tip. By turning
the B.B.T. potentiometer clockwise/counter-clockwise, the wire which is exiting from the torch at
the end of the welding will become shorter or longer.
Over temperature pilot lamp
6.
This pilot lamp will light if the over temperature thermostat operates. During an over temperature
condition, the output of the power source will be disabled, but the fan should continue to operate
to cool the machine. The pilot lamp will automatically extinguish after the machine has cooled
sufficiently. For some models the main Switch (1) functions as over temperature pilot lamp.
fuse: This fuse protects the 230Vac auxiliary circuit
7.
This fuse is rated at 1A, 250Vac. Never replace it with a fuse of lower voltage rating as this could
cause serious damage to the equipment.
Torch connection
8.
8.0
Only for models fitted with timer for spot welding.
It is possible to spot weld two sheets of up to 0,8mm thickness mild steel by replacing the torch gas nozzle
with a spot welding nozzle (not supplied). Select the spot welding function by adjusting the timer . Place two
sheets one upon another; place the nozzle on the upper sheet and then press the torch trigger ensuring
that the sheets are in contact. Press the trigger to spot weld the first sheet to the second one. The spot
welding will automatically stop when the adjusted time has passed. For spot welding, the machine must
be set at maximum current and maximum wire speed. It is advisable to use 0,8mm ø wire.
9.0
The machine will be set up as for mild steel except for the following changes:
• 100% ARGON as welding protective gas.
• Ensure that your torch is set up for aluminium welding:
1. The lenght of the torch cable should not exceed 3m (it is advisable not to use longer torches).
2. Install a teflon wire liner (follow the instructions for the renewing of the wire liner at paragraph 6).
3. Ensure that drive rolls are suitable for aluminium wire.
• Use contact tips that are suitable for aluminium wire and make sure that the diameter of the con-
tact tip hole corresponds to the wire diameter that is going to be used.
10.0
WARN ING: make sure the polarity is correctly set. for GAS welding the torch must be
connected to the positive terminal (+), while the ground cable must be connected to the
negative terminal (-).
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spot Welding

aluminium Welding

preparation For Welding

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