SUPERIOR 240 CE
sends it to block 15 (duty cycle maker).
(control board).
If one of the three input phases is lost this alarm cuts in.
Block 17
Alarm Block
Block 25
Consisting of: Q1, D12, D13, R80, Q12 (control board)
Shunt Amplifier
When an alarm is detected, the output current is cut off by
Consisting of: U4 (control board)
operating directly on block 15 (duty cycle maker) in the
Amplifies the signal from block 10 (inductance shunt) and
event of:
makes it appropriate for block 26 (maximum current
1) Triggering of thermostatic capsule on secondary board
limiter).
dissipator diodes.
2) Triggering of thermostatic capsule on power
Block 26
transformer.
Maximum current limiter
3) Triggering due to undervoltage
.
Consisting of: R62 (control board)
4) Triggering due to overvoltage
.
Processes the information from block 25 (shunt amplifier)
5) Phase loss at input.
and, using R62, regulates the maximum welding current to
6) Short circuit at output (electrode holder clamp and earth
be supplied by the power source.
cable connected to each other or electrode stuck to
This signal is scaled down so that it can be processed and
piece being welded).
compared in l block 16 (adder).
Block 18
Block 27
Potentiometer
Function selector
Consisting of: R72 (control board)
Consisting of: S1
Used to set the reference voltage needed to adjust the
Uses the switch to select the type of welding process:
MMA
output current: changes the current from the minimum to
OR TIG-LIFT.
the maximum value.
Block 28
Block 19
Short circuit detector
Yellow LED alarm light
Consisting of: U3B (control board)
Consisting of: D35 (control board)
If the welding voltage P is lower than 10V this circuit causes
It is switched on by block 17 (Alarm Block) if an alarm
block 30 to trigger (arc force)
occurs.
Block 29
Block 20
Hot Start
Overvoltage safeguard
Consisting of: U3D, Q3, C9, Q2 (control board)
Consisting of: U5A, R38, R40
When welding starts this block generates a temporary
If the main supply voltage exceeds the maximum value this
overcurrent, which can be adjusted by R72 and is used to
safeguard triggers (a tolerance of approx. ±15% of the
pre-heat the electrode in MMA.
power supply voltage is allowed: outside this range the
safeguard triggers).
Block 30
Arc Force
Block 21
Consisting of: Q7, C14, Q6 (control board)
Undervoltage safeguard
If the arc voltage falls below 10V, this block produces a
Consisting of: U5B, R30, R32
temporary increase in output current, which is used to
If the main supply voltage falls below the minimum allowed
detach the electrode from the piece after sticking has
value this safeguard triggers (a tolerance of approx. ±15%
occurred.
of the power supply voltage is allowed: outside this range
the safeguard triggers).
Block 31
Short circuit delay
Block 22
Consisting of: U3A (control board)
Secondary diodes thermostat
If output shorting persists, this block switches off the power
Consisting of: thermostatic capsule ST1
source by means of block 17 (alarm block).
When the temperature of the secondary board dissipator
reaches 70
°
C (approx.) this safeguard triggers. Reset is
Block 32
automatic when the cause for alarm is removed.
Hot-Start/Arc-Force Potentiometer
Consisting of: R77 (control board)
Block 23
Used to set the reference voltage required to adjust the
Power transformer thermostat
strike current percentage (0-100%) (Hot-Start) and the
Consisting of: thermostatic capsule ST2
antistick overcurrent (Arc-Force).
When the temperature of the power transformer
is too high
this safeguard triggers. Reset is automatic when the cause
Block 33
for alarm is removed.
Auxiliary Power Supply
Consisting of: R111, R45, D15 (control board)
Block 24
This block reserves a voltage (about 11Vdc) for the
Phase loss
shorting detection circuit so as to detect the shorting at
Consisting of: ISO2, ISO3 opto insulators board, U5C
output, if the power is disabled.
4