Tecnica 150, 152, 170, 168GE Service manual
cod. 988666
TECNICA 150-152-170-168
GE
TECNICA 140.1 - 142
inverter
TROUBLESHOOTING
TROUBLESHOOTING
TROUBLESHOOTING
TROUBLESHOOTING
AND REPAIR MANUAL
AND
AND REPAIR MANUAL
AND REPAIR MANUAL
CONTENTS PAGE
OPERATION AND WIRING DIAGRAMS................ 2
Block diagram 2
Analysis of the block diagram 3
Illustrations 5
Wiring diagrams 6
REPAIR GUIDE.......................................................10
Equipment required 10
General repair instructions 11
Troubleshooting and remedies 11
Testing the machine 14
Illustrations 17
REPAIR MANUAL
SPARE PARTS LIST...............................................18
REPAIR SHEET......................................................20
“reparation no problem !”
TECNICA 150-152-170-168GE
OPERATION AND WIRING DIAGRAMSOPERATION AND WIRING DIAGRAMS
OPERATION AND WIRING DIAGRAMSOPERATION AND WIRING DIAGRAMS
BLOCK DIAGRAM
OUTPUT
EMC FILTER II°
INDUCTANCE
DIODES
SECONDARY
POWER
TRANSFORMER
CURRENT
TRANSFORMER
CHOPPER
10
MAXIMUM
9
8
7
CURRENT ADJUST.
ALARM LED
19
17
CURRENT
POTENTIOMETER
ALARM BLOCK
ADDER
18
16
15
CONTROLLO
DUTY CYCLE
6
5
PRIMARY CURRENT
READER AND LIMITER
DRIVER
13
12
MAKER
14
FILTER
RECTIFIER BRIDGE
PRE-CHARGE
PRIMARY
EMC FILTER
INPUT
4
3
2
1
FLY-BACKPOWER
POWER SUPPLY
POWER SUPPLY
SUPPLY
LED
IDENTIFICATION
115/230V
+ |
11
25
24
CHANGE
VOLTAGE
UNDERVOLTAGE
SAFEGUARD
FAN
26
OVERVOLATGE
SEFEGUARD
23
GALVANIC
SEPARATOR
POWER
TRANSFORMER
THERMOSTAT
22
21
20
(only for Tecnica 152)
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TECNICA 150-152-170-168GE
ANALYSIS OF THE BLOCK DIAGRAM
NOTE: Unless indicated otherwise, it should be assumed that
the components are assembledon thepower board.
Block 1
EMC Filter
Consisting of: C1, C2,C3, L1.
Prevents noise from the machinefrom beingtransmitted along
the main power lineand viceversa.
Block 2
Pre-charge
Consisting of: K1, R1.
Prevents the formation of high transitory currents that could
damage the main power switch, the rectifier bridge and the
electrolytic capacitors.
When the power source is switched on the relay K1 is deenergised, capacitors C4, C5, C6, C7, C8 are then charged
by R1. When the capacitors are charged the relay is
energised.
Block 3
Rectifier bridge
Consisting of: D1.
Converts the mains alternating voltage into continuous pulsed
voltage.
Block 4
Filter
Consisting of: C4, C5,C6, C7.
Converts the pulsed voltage from the rectifier bridge into
continuous voltage .
(C7 fitted on Tecnica 152 only)
Block 5
Chopper
Consisting of: Q1, Q2,Q3, Q4.
Converts the continuous voltage from the filter into a high
frequency square wave capable of piloting the power
transformer.
Regulates the power according to the required welding
current/voltage.
Block 6
Current transformer
Consisting of: T2.
The C.T. is used to measure the current circulating in the
power transformer primary and transmit the information to
block 14 (primary currentreader andlimiter).
Block 7
Power transformer
Consisting of: T3.
Adjusts the voltage and current to values required for the
welding procedure. Also forms galvanic separation of the
primary from the secondary (welding circuit from the power
supply line).
Block 8
Secondary diodes
Consisting of: D20, D21,D22, D23.
D20, D21 converts the current circulating in the transformer to
a single direction, preventingsaturation ofthe nucleus.
D22, D23 recirculate the inductance output current (block 9)
when the IGBT's are not conducting, bypassing the power
transformer (block 7).
Block 9
Inductance
Consisting of: L2.
Levels the secondary board diodes’ output current making it
practically continuous.
Block 10
Secondary EMC Filter
Consisting of: C21, C22.
Prevents noise from the power source from being transmitted
through the welding cablesand viceversa.
Block 11
Flyback power supply
Consisting of: T1, U2.
Uses switching methods to transform and stabilise the voltage
obtained from block 4 (filter) and supplies auxiliary voltage to
power block 12 (driver)and thecontrol board correctly.
Block 12
Driver
Consisting of: ISO2, ISO3.
Takes the signal from block 11 (flyback power supply) and,
controlled by block 14 (duty cycle maker), makes the signal
suitable for piloting block6 (chopper).
Block 13
Primary current reader andlimiter
Consisting of: R63, R64, R65 and partof thecontrol section.
Reads the signal from block 6 (current transformer) and scales
it down so it can be processed and compared in blocks 14 and
15.
Block 14
Duty cycle maker
Consisting of: U2 (controlboard).
Processes the information from block 15 (adder) and block 13
(primary current reader and limiter) and produces a square
wave with variable duty cycle limiting the primary current to a
maximum pre-set value underall circumstances.
Block 15
Adder
Consisting of: U1C (controlboard).
Gathers all the information from block 13 (primary current
reader and limiter), from block 16 (alarms) and from block 18
(current potentiometer), and produces a signal with a suitable
voltage for processing byblock 14(duty cycle maker).
Block 16
Alarm Block
Consisting of: U1A, U1B(control board).
When an alarm is detected the power source output current is
drastically reduced by making direct adjustments to block 14
(duty cycle maker) and directly changing the reference signal
obtained from block 18(current potentiometer).
Block 17
Alarm LED
Consisting of: D14.
It is switched onby block16 (alarms) in the eventof:
1) Triggering of thermostatic capsule/thermostat on power
transformer.
2) Triggering dueto undervoltage.
3) Triggering dueto overvoltage.
4) Short circuit at output (electrode holder clamp and earth
cable connected to one another or electrode stuck to piece
being welded).
-3-
TECNICA 150-152-170-168GE
Block 18
Current potentiometer
Consisting of: R52.
This is used to set the reference voltage needed to adjust the
output current: when the potentiometer knob is turned the
cursor voltage varies, thus varying the current from the
minimum to the maximumvalue.
Block 19
Maximum current adjustment
Consisting of: R56, R57,R58.
Used to adjust the maximum cutting current to be supplied by
the power source.
Block 20
Power transformer thermostat
Consisting of: ST1.
When the temperature of the power transformer is too high,
the thermostat transmit the information to block 21 (galvanic
separation). It is reset automatically after the alarm condition
has ceased.
Block 21
Galvanic separator
Consisting of: ISO1.
The signal arriving from blocks 20 and 21 (power transformer
thermostat and secondary diodes) is separated galvanically
and sent to block 16 (alarms) for detection of a possible alarm
event.
Block 26
Fan
Consisting of: V1.
Powered directly by block 13 (power supply) and cools the
power components.
Block 22
Overvoltage safeguard
Consisting of: R71, R73and partof the control section.
If the main supply voltage exceeds the maximum value this
safeguard triggers (a tolerance of approx. ±15% of the power
supply voltage is allowed: outside this range the safeguard
triggers).
Block 23
Undervoltage safeguard
Consisting of: R72, R70and partof control board.
If the main supply voltage falls below the minimum allowed
value this safeguard triggers (a tolerance of approx. ±15% of
the power supply voltage is allowed: outside this range the
safeguard triggers).
Block 24
Power supply identification 115/230V
Consisting of: U1A, Q2,Q1 (voltagechange board).
This is only present on machines with the automatic
identification function.
Identifies the power supply voltage level (115V or 230V) and
compares the values with a reference signal. The comparison
causes enabling of block 5 (filter) for operation in standard
mode (230V) or as voltage duplicator (115V). This block also
adjusts for the correct maximum current in relation to the
different operatingmodes.
Block 25
Power supply LED
Consisting of: D12 (D13for Tecnica 152).
Indicates when the power source is correctly powered and
ready for use.
On machines operating exclusively at 230V it is green. On
machines with automatic voltage identification (Tecnica 152) it
is green for operation at 230V and orange for operation at
115V.
-4-
ILLUSTRATIONS
TECNICA 150-152-170-168GE
Power board
(5)
CHOPPER
(12)
DRIVER
(1)
PRIMARY EMC
FILTRE
(3)
RECTIFIER
BRIDGE
PRE-CHARGE
(2)
(4)
FILTER
(11)
FLY-BACK
POWER SUPPLY
CONTROL
BOARD
(18)
CURRENT
POTENTIOMETER
(25)
POWER
SUPPLY
LED
(17)
ALARM
LED
(10)
SECONDARY
FILTER EMC
(5)
CHOPPER
(7)
POWER
TRANSFORMER
-5-
(8)
SECONDARY
DIODES
(9)
INDUCTANCE
(6)
CURRENT
TRANSFORMER
TECNICA 150-152-170-168GE
WIRING DIAGRAMS
Wiring diagram
general -TECNICA 150 - 170 - 168GE
Wiring diagramgeneral TECNICA 152-
-6-
TECNICA 150-152-170-168GE
Wiring diagram power board - power supply / control
-7-
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