ESAB Caddy Mig C200i User manual

0349 300 095 Valid for serial no. 932--xxx--xxxx101222
Caddy
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RR
R
Mig C200i
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-- 2 -- TOCe
READT ISFIRST 4.................................................................
INTRODUCTION 4...................................................................
TEC NICALDATA 5.................................................................
WIRINGDIAGRAM 6.................................................................
Componentdescription 6..........................................................
CaddyrMigC200i 7...............................................................
DESCRIPTIONOFOPERATION 8.....................................................
AP1:1.EMImainsfilter 10............................................................
AP1:2.Pre--chargecircuit 10.........................................................
AP1:3.Two--switchforwar converter 10...............................................
AP1:4.Currentsensetransformer 10..................................................
AP1:5.Highfrequencytransformer 10.................................................
AP1:6.Thermalprotectionsensors 11.................................................
AP2Analoguecontrolboard 13.....................................................
HighVoltageCircuits 13..............................................................
AP2:1H. Voltage supervision an PFC control 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP2:2H.Auxiliarypowersupply 14....................................................
AP2:3H. Thermal protection on the primary si e 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LowVoltageCircuits 16..............................................................
AP2:1L.Comman system 16........................................................
AP2:2L.Electromagneticvalve 18.....................................................
AP2:3L.Shortarccontrol 19..........................................................
AP2:4L. Wire fee er motor spee controller 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP2Componentslayout 23.........................................................
AP3MMCpanel 24.................................................................
AP3:1,2,3. Manual, igital an analog input circuits 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
AP3:4.Microprocessoran itscircuits 27...............................................
AP3:5.Powersupplies 28............................................................
AP3:6.Analogoutputs 29............................................................
AP3:7.Digitaloutputs 30.............................................................
AP3:8.LCD isplay 30..............................................................
AP3Componentslayout 31.........................................................
SERVICEINSTRUCTIONS 32..........................................................
WhatisESD? 32...................................................................
Beforetheservicework 32..........................................................
andlingofthecontrolPCB 33.....................................................
Insulationresistancemeasurement 33...............................................
Assemblyofthehousing 34........................................................
Faulttracing 35....................................................................
Generalfailureofthepowerblock 36................................................
INSTRUCTIONS 37...................................................................
SAFETY 37........................................................................
INSTALLATION 37....................................................................
Placing 38.........................................................................
Mainspowersupply 38.............................................................
OPERATION 39.......................................................................
Connectionandcontroldevices 39..................................................
Operation 40.......................................................................
Errorcodes 42.....................................................................
Settingthedynamics (Fe/SS) 42....................................................
Polaritychange 43.................................................................
Wirefeedpressure 44..............................................................
Replacingandinsertingwire 44.....................................................
Shieldinggas 45...................................................................
Overheatingprotection 45..........................................................

-- 3 -- TOCe
MAINTENANCE 46....................................................................
Inspectionandcleaning 46.........................................................
Changingthewireliner 46..........................................................
ORDERINGOFSPAREPARTS 47......................................................
NOTES 48...........................................................................

Edition 101222
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READ T IS FIRST
Maintenance an repair work shoul be performe by an experience person, an
electrical work only by a traine electrician. Use only recommen e replacement parts.
This service manual is inten e for use by technicians with electrical/electronic training for
help in connection with fault--tracing an repair.
Use the wiring iagram as a form of in ex for the escription of operation. The circuit
boar is ivi e into numbere blocks, which are escribe in ivi ually in more etail in
the escription of operation. All component names in the wiring iagram are liste in the
component escription.
This manual contains etails of all esign changes that have been ma e up to an
inclu ing December 2010.
The Caddyr
rr
rMig C200i is designed and tested in accordance with international and
European standard IEC/EN 60974--1/--5/--10 and EN 61000--3--12.
On completion of service or repair work, it is the responsibility of the person(s) etc.
performing the work to ensure that the product does not depart from the requirements
of the above standard.
INTRODUCTION
Caddy
R
RR
R
Mig C200i is an inverter base , portable semiautomatic wel er in a
compact esign, inten e for MIG/MAG wel ing.
The possibility of wel ing with homogeneous wire/shiel ing gas an wel ing with
gasless tubular wire is obtaine by switching the + an -- connections on the
switching terminal close to the wire fee unit.
The machine operates with wire iameters from ∅ 0,6 to ∅ 1,0 mm. As shiel ing gas
pure argon, mixe gas or pure CO
2
may be use .
The Ca y
R
Mig C200i raws current with near--unity power factor which pro uces
very low level harmonics in the mains.

Edition 101222
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TEC NICAL DATA
Voltage 230 V, 1∼50/60 z
Permissible load at
100% uty cycle 100 A
60 % uty cycle 120 A
25 % uty cycle 180 A
Setting range (DC) 30 -- 200 A
Open circuit voltage 60 V
Open circuit power 15 W
Efficiency 82%
Power factor 0.99
Wire feed speed 2 -- 12m/min
Wire diameter
Fe
CW
Ss
Al
∅0.6--1.0
∅0.8--1.0
∅0.8--1.0
∅1.0
Bobbin size ∅200 mm
Dimensions lxwxh 449x198x347
Weight 12 kg
Operating temperature --10 to +40
o
C
Enclosure class IP 23C
Application classification
Duty cycle
The uty cycle refers to the time as a percentage of a ten--minute perio that you can wel at a cer-
tain loa without overloa ing.
Enclosure class
The IP co e in icates the enclosure class, i. e. the egree of protection against penetration by soli
objects or water. Equipment marke IP23C is esigne for in oor an out oor use.
Application class
The symbol in icates that the power source is esigne for use in areas with increase
electrical hazar .

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WIRING DIAGRAM
Component description
WARNING !
STATIC ELECTRICITY can damage circuit
boards and electronic components.
S
SS
SObserve precautions for handling electrostatic
sensitive devices.
S
SS
SUse proper static--proof bags and boxes.
ESD
WARNING !
igh DC voltage may remain on the electrolytic capaci-
tors on the power board.
Check the voltage and discharge capacitors if needed.
AP1
Power boar
AP2
Control boar
AP3
MMC boar
K1
Gas valve
M1
Wire fee ing motor
M2
Fan
S1
Torch switch
Q1
Mains switch

Edition 101222
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Caddyr
rr
rMig C200i

Edition 101222
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DESCRIPTION OF OPERATION
Ca yrMig C200i is a set of following mo ules:
Spower PCB -- AP1
Scontrol PCB -- AP2
SMMC panel -- AP3
Sgas valve -- K1
Swire fee ing motor -- M1
Sfan -- M2
The power PCB contains all the track of energy conversion. It is supplie from the 230V
50/60Hz mains. There is the EMI filter on the input, then half--controlle thyristor bri ge.
Thyristor are not fire until DC bus capacitors are not charge via pre--charge circuit.
Between the rectifier an the DC bus capacitors the boost converter is place . It contains
the high frequency in uctor, the switch (MOSFET) an the io e. Control system of the
boost converter is place on the control PCB (AP2). The switch in boost converter control
provi es: a) sinusoi al shape of the input mains current, b) stabilise voltage on the DC
bus.
By the principle, the voltage is higher the amplitu e value of the AC input voltage. In the
Ca yMigs it is 390...400V. The boost converter’s frequency is 70 kHz. The converter that
provi es the power to wel ing has two switch forwar topology. The switching frequency is
70 kHz. By the principle, the maximum converter’s uty cycle is less then 50%. Transformer
ratio is 5,5:1, what means that peak voltage in secon ary win ing of the power transformer
is about 70V. The high frequency rectifier + in uctor are connecte to the transformer’s
secon ary win ing. The control circuits of the forwar converter are inclu e in the control
PCB.
Beyon the both converters control circuits the control PCB contains also the rest of nee e
circuits. On the primary si e it inclu es voltage supervisor, auxiliary power supply, primary
circuits overheating an overvoltage protection. On the secon ary si e there are: process
sequence an control, short arc control, overheating protection, wire fee spee regulator,
an gas valve controller.

Edition 101222
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Edition 101222
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s1Ca 200
AP1:1. EMI mains filter
The EMI mains filter contains capacitors an in uctors inten e for suppression of
the common--mo e interferences an the ifferential--mo e interferences. The EMI
filter contains following parts: L05, C1, L01, L02, C5, C8, C16. The resistors R30,
R31 provi es ischarge path for the filter’s capacitors.
AP1:2. Pre--charge circuit
The pre--charge circuit contains io es V01, V02 an PTC resistors B01, B02.
Internal io es MV3, MV4 of the power mo ule together with io es V01, V02
create the non--controlle rectifier. The filter capacitors C2, C21, C22 are charge
by this rectifier via non--linear resistor B01, B02 up to the amplitu e value of the
mains voltage. It is lower then the eventual DC bus voltage, nevertheless it protects
the supply mains an capacitors from the big inrush currents an makes easier
start of the PFC boost converter.
After charging of the capacitors, the auxiliary supply place on the control PCB,
starts to work, provi ing also firing pulses to thyristors. The main rectifier ma e of
thyristors MV1, MV2, an io es MV3, MV4 takes over the rectifying role.
The boost converter create by the in uctor L03, switch MV5 (an MV6), io es
MV7, MV8 (MV9, MV10) starts working, charging the DC bus capacitors to
390...400V.
AP1:3. Two--switch forward converter
The two--switch forwar converter is create on transistors MV11, MV18, an
io es MV14, MV15. Others io es an transistors if exists, are not activate .
There is the current sense resistor MR1 place on the (--) place before the PFC
converter. It’s purpose is to provi e information of the momentary current to the
PFC control system what is nee e for creation of the average current control loop
in the PFC control.
Drivers for the switches in the PFC an forwar converters are place on the power
PCB.
AP1:4. Current sense transformer
The current sense transformer T02 is place on the (--) line. It senses the pulse
current, which is nee e for creation of the peak current control loop in the
inverter’s control system.
AP1:5. igh frequency transformer
The high frequency transformer is mounte on the power PCB. Due to high power
sol ering an anticipate high reliability, replacement of the transformer is not
subject of service routines.

Edition 101222
Fixing of the
PTC thermal sensor
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s1Ca 200
Numbers of outlets of the power transformer.
AP1:6. Thermal protection sensors
The thermal protection sensors are place insi e the power mo ules (or mo ule)
an on the heatsink of the output rectifier. In the power mo ule there are (is) NTC
(negative temperature coefficient) non--linear sensor -- 22kΩ@ 25_C, while on the
output rectifier the PTC (positive temperature coefficient) 1,0 kΩ@ 25_C linear
sensor is installe .
The replacement of the sensor in the heatsink can be carrie out only along with
amaging the ol sensor. The new one shoul be installe by means of the
electrically non--con uctive an thermally con uctive silicon rubber.

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Edition 101222
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AP2 Analogue control board
The analogue control PCB contains circuits connecte to the input (high voltage,
primary) an circuits connecte to the output (low voltage, secon ary).
igh Voltage Circuits
High voltage circuits (primary si e) are place on the right part of the PCB an they
are connecte to the external circuits by means of the connector CN1. High voltage
circuits contains:
Svoltage supervision circuits
SPFC control circuits
Sauxiliary power supply
Stemperature sensors circuits
AP2:1 . Voltage supervision and PFC control
Voltage supervision circuits senses the DC bus voltage (inputs 19,20 CN1) an the
rectifie input voltage (input 15 CN1). As long as voltage are not within limits high
voltage enable line (HV_ENABLE) is groun e by means of transistor Q1.
Operation of the PFC an auxiliary power supply is isable . The reset IC4 is use
for the voltage control. Two of inputs are connecte to the rectifie input voltage,
one to the DC bus. Operation of the machine is isable as long as the a.c. voltage
is less then 188 Vrms or rops un er 177 Vrms (SENSE3), an DC bus voltage is
less then 259V or rops below 173V (SENSE1). Another sense input (SENSE2)
has very low time constant along with voltage limitation. It provi es fast isable
uring the machine switching off.

Edition 101222
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s1Ca 200
PFC control is built on the specialise integrate circuit IC3. PFC control senses
the DC bus voltage, input current (5,6 CN1) an input voltage, provi ing the
constant 390...400V on the DC bus along with sinusoi al form of the input current.
This goal is achieve by the control of the switch in the boost converter place on
the power PCB. Actually, the control circuit place on the control PCB pro uces the
rive signal for PFC switch.
Specialise PFC controller (IC3), use in the present solution, oes not provi e
overvoltage protection. Therefore, extra two comparators were applie to control
the DC bus voltage. There is a two--step overvoltage protection. First, on the lower
level simply cuts off the rive signal from the PFC control IC by means of the logic
AND gate.
Secon level is higher the first, an it resets the PFC control IC via it’s soft start
input.
The system of overvoltage protection is nee e especially for work with engine
riven generator, where the voltage surges occur at the en of the wel ing.
AP2:2 . Auxiliary power supply
The auxiliary power supply provi es power for primary an secon ary control
circuits. Basically it pro uces +15V supply for the primary circuits an galvanically
separate +24V supply for secon ary circuit. In a ition it provi es firing pulses to
the thyristor in the input rectifier.
The auxiliary power supply is switche off by means of the voltage control circuit
(HV_ENABLE). Therefore thyristor firing pulses are not elivere until DC bus
capacitors are charge to the peak input voltage.

Edition 101222
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The auxiliary power supply is built as flyback converter. Estimate maximum power
of it is 25W. The most loa e output is the +24V secon ary si e. It provi es the
power for all low voltage control circuits an also power for the fan an the gas
valve.
The wire fee er motor is supplie from the auxiliary win ing of the power
transformer. However it’s energy storage capacitor is pre--charge from the +24V,
to provi e power for uninterrupte start of the motor.

Edition 101222
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s1Ca 200
AP2:3 . Thermal protection on the primary side
As temperature sensors (sensor) are on the high voltage potential, the thermal
protection circuit (fig. ) is place on the high voltage si e, then the 0/1 signal is
transferre via the optocoupler IC2 with exten e isolation, to the secon ary
circuits.
Low Voltage Circuits
Low voltage circuits (secon ary si e) are place on the left part of the PCB an
they are connecte to the external circuits by means of the connector existe
connectors, except the CN1.
Low voltage circuits inclu e:
Scomman system of the semiautomatic wel er
Sshort arc control system
Swire fee er motor spee control circuit
Slow--energy control of the electromagnetic valve
AP2:1L. Command system
Comman system pro uces assume program control on iscrete inputs an
outputs. In particular it provi es logic epen encies an generates the sequence
control of parts of the semiautomatic wel er.

Edition 101222
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The start signal from the wel ing torch is the basic input of the comman system.
As shown on the fig. the start signal can be isable in several cases:
Sthermal protection from the primary si e (IC2),
Sthermal protection form the secon ary si e (CN4.5,6),
Storch switch is presse uring the power up (charging of the C342, hol by the
presse switch)
Slack of the +24V_ENABLE signal
As shown any of liste cases keeps the ENABLE line low. Note that even after
removal all liste error signals, the machine is kept in isable state, until the torch
switch is release . This is a itional protection of unintentional switching on.
The comman system is not shown entirely. The sequence of operation of the
subassemblies of the semiautomatic wel er is shown on the fig.
Note that there are no proportions on this rawings.

Edition 101222
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s1Ca 200
As shown, there is 0,2 gas pre--flow elay. The power source is kept on until the
motor is running.
AP2:2L. Electromagnetic valve
The electromagnetic valve control works in a specific mo e.
As shown on the iagram the first 0,2 s coil of the valve is supplie from 24 volts
.c. Then the generator starts running, provi ing 50%, 20kHz, 24V amplitu e
supply of the gas wel ing. In result the rawn power is re uce own to1/4 of the
rate power, but the valve ue to its relay--type characteristics is kept open.

Edition 101222
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AP2:3L. Short arc control
The voltage reference is proportional with ifferent coefficients to:
a. wire fee spee reference
b. voltage on the Umin input
c. voltage on the Upot input
In the previous solution the source a. was replace by the EMF -- voltage
proportional to the actual wire fee spee , i.e. the EMF voltage was 0, when the
motor was stoppe .
In one or either way, the voltage reference was in relation to the wire fee spee .
In the actual solution it is achieve by groun ing pin 18 of CN6. In previous
solution, the EMF signal was elivere to micro controlle an then subtracte from
the reference with a equate coefficient.

Edition 101222
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s1Ca 200
Voltage fee back is given on the CN4.1. Note that low voltage groun (GND_INV)
is connecte via CN4.2 to the power supply (+). It enables creation of the summing
point in system with unipolar supply. Nevertheless the voltage fee back inverting
amplifier gives the signal in opposite phase. This signal is elivere to the next
inverting amplifier, which is not shown on the rawing. This amplifier also a s the
fraction proportional to the ramp signal, create uring short circuit. In his way, a
current reference signal is elivere to the peak current mo e PWM integrate
circuit IC11.