Tecnica 144-164 Service manual
cod. 988637
TECNICA 144-164
TECNICA 140.1 - 142
inverter
TROUBLESHOOTING
TROUBLESHOOTING
TROUBLESHOOTING
TROUBLESHOOTING
AND REPAIR MANUAL
AND
AND REPAIR MANUAL
AND
CONTENTS PAGE
OPERATION AND WIRING DIAGRAMS................ 2
Block diagram 2
Analysis of the block diagram 3
Illustrations 5
Wiring diagrams 6
REPAIR GUIDE...................................................... 9
Equipment required 9
General repair instructions 10
Troubleshooting and remedies 10
Testing the machine 13
Illustrations 15
REPAIR MANUAL
REPAIR MANUAL
SPARE PARTS LIST...............................................18
REPAIR SHEET......................................................20
“reparation no problem !”
TECNICA 144 - 164
OPERATION AND WIRING DIAGRAMSOPERATION AND WIRING DIAGRAMS
OPERATION AND WIRING DIAGRAMSOPERATION AND WIRING DIAGRAMS
BLOCK DIAGRAM
OUTPUT
EMC FILTER II°
INDUCTANCE
SECONDARY
DIODES
POWER
TRANSFORMER
CURRENT
TRANSFORMER
CHOPPER
10
MAXIMUM
9
8
8
7
6
5
CURRENT ADJUST.
ALARM LED
PRIMARY CURRENT
READER AND LIMITER
DRIVER
CURRENT
23
21
17
14
POTENTIOMETER
ALARM CLOCK
ADDER
DUTY CYCLE
MAKER
SEPARATOR
TRANSFORMER
22
20
19
18
15
TRANSFORMER
PILOT
16
FILTER
RECTIFIER BRIDGE
PRE-CHARGE
PRIMARY
EMC FILTER
INPUT
4
3
2
1
AUXILIARY POWER
SUPPLYTRIGGER
VOLTAGE
RECTIFIER
OVERVOLATGE
SEFEGUARD
OVERVOLTAGE
PROTECTION
12
11
t
27
t
26
AUXILIARY POWER
ALIMENTATORE
POWER SUPPLY
FAN
SUPPLY
FLY-BACK
LED
11
13
28
THERMOSTATS
GALVANIC
SEPARATOR
25
29
POWER
TRANSFORMER
THERMOSTAT
24
-2-
TECNICA 144 - 164
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, T4,C8, C15.
Prevents noise from the machine from being transmitted along
the main power lineand viceversa.
Block 2
Pre-charge
Consisting of: PD1, R4.
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 PD1 is deenergised, capacitors C21, C22, C27 are then charged by R4.
When the capacitors arecharged therelay is energised.
Block 3
Rectifier bridge
Consisting of: PD1.
Converts the mains alternating voltage into continuous pulsed
voltage.
Block 4
Filter
Consisting of: C21, C22,C27.
Converts the pulsed voltage from the rectifier bridge into
continuous voltage.
Block 9
Inductance
Consisting of: L1.
Levels the secondary board diodes’ output current making it
practically continuous.
Block 10
Secondary EMC Filter
Consisting of: C28, C33.
Prevents noise from the power source from being transmitted
through the welding cablesand viceversa.
Block 11
Voltage rectifier
Consisting of: D11,C18.
Rectifies and filters the voltage from the tertiary winding of the
power transformer (block 7).
Block 12
Auxiliary power supply trigger
Consisting of: R18, R35,C20.
Via the resistors, the power source supplies the necessary
voltage to power block13 (powersupply).
Block 13
Auxiliary power supply
Consisting of: U3, C17.
Stabilises the voltage at 12Vdc for the power arriving from
block 12 (auxiliary power supply trigger) and from block 11
(voltage rectifier).
Block 5
Chopper
Consisting of: Q5, Q8.
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 17 (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: D32, D33,D34 .
D34 converts the current circulating in the transformer to a
single direction, preventing saturationof thenucleus.
D32, D33 recirculate the inductance output current (block 9)
when the IGBT's are not conducting, bypassing the power
transformer (block 7).
Block 14
Driver
Consisting of: Q6, D19,D23, Q7,D27, D26
Picks up the signal arriving from block 15 (separator
transformer) and under the control of block 17 (transformer
pilot) adjusts it tosuit pilotingof block 5 (chopper).
Block 15
Separator transformer
Consisting of: T1.
Supplies two signals, which are separated galvanically from
one another, that will besent to power block 14 (driver).
Block 16
TransformerPilot
Consisting of: Q4, D20,D22, D24.
Amplifies the signal arriving from block 18 (duty cycle maker),
needed to pilot block15 (separatortransformer).
Block 17
Primary current reader andlimiter
Consisting of: D2, R25.
Reads the signal from block 6 (current transformer) and scales
it down so it can be processed and compared in blocks 18 and
19.
Block 18
Duty cycle maker
Consisting of: U1.
Processes the information from block 19 (adder) and block 17
(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.
-3-
TECNICA 144 - 164
Block 19
Adder
Consisting of: U2C.
Gathers all the information from block 17 (primary current
reader and limiter), from block 20 (alarms) and from block 22
(current potentiometer), and produces a signal with a suitable
voltage for processing byblock 18(duty cycle maker).
Block 20
Alarm Block
Consisting of: Q3, R43,R44, R38,R36
When an alarm is detected the power source output current is
drastically reduced by making direct adjustments to block 18
(duty cycle maker) and directly changing the reference signal
obtained from block 22(current potentiometer).
Block 21
Alarm LED
Consisting of: D12.
It is switched onby block20 (alarms) in the eventof:
1) Triggering of thermostatic capsule/thermostat on power
transformer.
2)
Triggering due toundervoltage.
3) Triggering due to overvoltage.
4) Short circuit at output (electrode holder clamp and earth
cable connected to one another or electrode stuck to piece
being welded).
Block 27
Undervoltage safeguard
Consisting of: R39, R64, U2B .
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 28
Power supply LED
Consisting of: D10.
Indicates when the power source is correctly powered and
ready for use.
Block 29
Fan
Consisting of: V1.
Powered directly by block 13 (flyback transformer) and cools
the power components.
Block 22
Current potentiometer
Consisting of: R23.
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 23
Maximum current adjustment
Consisting of: JP1, JP2,JP3.
Used to adjust the maximum cutting current to be supplied by
the power source.
Block 24
Power transformer thermostat
Consisting of: ST1.
When the temperature of the power transformer is too high,
this safeguard is triggered. It is reset automatically after the
alarm condition hasceased.
Block 25
Galvanic separation
Consisting of: ISO1.
The signal arriving from blocks 24 (power transformer
thermostat) is separated galvanically and sent to block 20
(alarms) for detection ofa possiblealarm event.
Block 26
Overvoltage safeguard
Consisting of: R1, R5,R14, R19,R24, R29, U2A.
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).
-4-
ILLUSTRATIONS
PRIMARY EMC
FILTRE
(1)
(3)
RECTIFIER
BRIDGE
TECNICA 144 - 164
(18)
DUTY CYCLE
MAKER
(12)
AUXILIARY POWER
SUPPLY TRIGGER
(2)
PRE-CHARGE
AUXILIARY POWER
Power boad
(13)
SUPPLY
(19)
ADDER
(4)
FILTER
(5)
CHOPPER
(15)
TRANSFORMER
SEPARATOR
(22)
CURRENT
POTENTIOM.
(28)
POWER
SUPPLY
LED
(21)
ALARM
LED
(6)
POWER
TRANSFORMER
(9)
INDUCTANCE
(10)
SECONDARY
FILTER EMC
(14)
DRIVER
(5)
CHOPPER
(7)
POWER
TRANSFORMER
(8)
SECONDARY
DIODES
-5-
WIRING DIAGRAMS
General wiring diagram
TECNICA 144 - 164
POWER PCB
OUT+OUT+
OUT-OUT-
J3J3
J2J2
J7J7
PE
PE
J1J1
54
54
S1
S1
ON/OFF
12
12
N (L2)
N (L2)
ON/OFF
L1
L1
J4+J4+
-6-
J4-J4-
V1
Fan
TECNICA 144 - 164
Wiring diagram power board – power supply
-7-
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