Download - LHF 630 & 800 file 0740 800 028

0740 800 028 Valid from machine no. 701--xxx--xxx9208--1

LHF 630/800

Service manual

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LIST OF CONTENTS PageRATING PLATE 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DESCRIPTION OF OPERATION OF LHF 630/800 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .BLOCK DIAGRAM, LHF 630/800 7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .COMPONENT DESCRIPTION, CIRCUIT DIAGRAM 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CIRCUIT DIAGRAM, LHF 630/800 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .DESCRIPTION OF OPERATION, CIRCUIT BOARD K70 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .CIRCUIT DIAGRAM, CIRCUIT BOARD K70 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .COMPONENT POSITIONS, CIRCUIT BOARD K70 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .REPLACEMENT OF THYRISTORS 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Note that only the English part of the instruction manual has been included.

INSTRUCTION MANUAL 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .PRESENTATION 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .INSTALLATION 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .TECHNICAL DESCRIPTION 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .TECHNICAL DATA 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .MAINTENANCE 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .STATIC CHARACTERISTICS 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .EFFICIENCY ç AND POWER FACTOR ë 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .SPARE PARTS LIST 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

This service manual is valid from machine no 701--XXX--XXX.

The date on the front page is followed by a one (9208 --1), this means that the layout has beenaltered, the contents are still the same as in 9208 though.

Rights reserved to alter specifications without notice.

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RATING PLATE

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1. The symbols indicate that the LHF 630 incorporates a transformer and a rectifier.

2. Current/voltage characteristic for MMA welding.

3. Indicates that the unit is intended for connection to a 3--phase supply at 50 or 60 Hz.

4. The machine’s serial number, consisting of three groups of figures (xxx yyy vzzz).

The first group (xxx) indicates the version. The numerals indicate the year and week ofapproval of the design version.

The second group (yyy) indicates the year and week of the machine’s final testing:e.g. 203 indicates 1992, week 3.

The final (vzzz) group consists of three or four numerals and is a consecutive serialnumber from 0001 to 9999.

5. These letter and numeral combinations indicate that ESAB complies with existing nation-al and international standards.

6. X = Intermittance factor: indicates for how long welding can be carried out at thespecified welding data, expressed as a percentage of a 5--minute period.

I2 = Current at the respective intermittance factor.U2= Arc voltage.Uo= No--load (open--circuit) voltage.

7. Supply voltages and primary current at various intermittance factors.

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DESCRIPTION OF OPERATION OF LHF 630/800

GENERAL DESCRIPTION

The LHF 630/800 are thyristor--controlled welding power sources incorporating mainsvoltage compensation and intended for MMA welding, TIG welding and air--arc gouging.The mains voltage compensation ensures that the arc voltage and welding current remainstable even though supply voltage may vary. Electronic control ensures that the weldingcurrent maintains its set value at all times. A single knob regulates the welding current overits entire range.

The following description refers to the block diagram on page 7.

1 Reference potentiometer K57 for adjusting the welding current. The current settingis as defined by the ISO line.

2 Reference potentiometer, connected to remote control socket K24, for remoteadjustment of the welding current.

3,4,5 Galvanically isolated remote control device.The remote control circuit employs a double--winding transformer (K52),associated rectifier and voltage stabilisation circuit, A/D converter, optocouplerand D/A converter.A pulsed voltage transfers the reference voltage from the remote control terminalsocket via the optocoupler to the D/A converter, the output of which is an analogreference voltage.

6 Selector switch K33 selects local or remote control of the reference voltage.The actual switching of the voltage reference signals is effected by analogswitches: the block diagram shows the switching only schematically.

7 Current reference boost in response to short circuits.

8 Reference voltage input from the local and external potentiometers respectively.

9 This circuit boosts the welding current in the event of an arc short circuit, thuspreventing the electrode from burning on to the work during welding. The currentreference signal is increased electronically via 7) and 20).

10 Assists striking of the arc by means of an elevated current reference signal duringstarting. See 14), ’Hot start’.

11 Reduces the welding current in the event of a long--duration short circuit, i.e. if theelectrode has burnt on to the workpiece. See 13), ’Foldback’.

12 Input for current signal from elevated shunt voltage.

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13 Foldback.This is a timer circuit that starts when the arc is short--circuited. It reduces thewelding current via 11) if the short circuit persists, i.e. if the electrode has burnt onto the workpiece. This helps to protect the thyristors against abnormally highand/or long--duration short circuits.The foldback feature operates only in the MMA welding mode.

14 Elevated starting current (starting boost, hot start)The starting current circuit briefly increases the welding current when starting toweld. The peak value of the starting pulse is about twice the set value of weldingcurrent, and gives the power source good starting characteristics during MMAwelding.Switch K79 (see 22), below) disconnects the feature during TIG welding.

15 Power supply unit for the electronic equipment, supplying stabilised DC at ±15 V.The neutral of the electronic circuitry is connected to the positive of the weldingvoltage (+ on K13).The power supply unit receives a three--phase alternating voltage from thesynchronising windings K1s3.

16 Control comparator/amplifier, which compares the voltage signals from 8--12) andthen amplifies the summing voltage to provide a suitable control voltage signal tothe trigger unit 17). The good dynamic welding performance of the LHF 630/800is partly due to the characteristics of the amplifier.The no--load detector 21) reduces the amplifier output signal when there is no arc.

17 Trigger unitThe trigger unit consists of three identical circuits (one for each phase). Eachcircuit provides trigger pulses for its thyristors, with phase angles in proportion tothe output voltage from the control amplifier. Auxiliary windings on the maintransformer provide synchronising signals.

18 Thermal overload cutout, which interrupts the pulses to the thyristors in the eventof high temperature of the thyristor cooling fins.

19 Shunt amplifier, amplifying the signal from the current shunt to a suitable level forinput to 12).

20 Short--circuit detector, sensing short circuits of the arc. See also 13).

21 No--load detector, senses no--load (open--circuit) voltage. See also 14) and 16).

22 Switch K79 (MMA/TIG), switching the control characteristics between MMA andTIG. When the switch is in the TIG position, the elevated starting current andfoldback circuits are disconnected: if this were not done, there would beconsiderable risk of burning through the workpiece.Switching is effected electronically: the block diagram shows only a schematicrepresentation.

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23 Control amplifier for air--arc gouging, producing a DC voltage that is proportionalto the reference voltage signal from 6), to give a constant--voltage characteristic.

The shunt signal from 19) is used to provide a current limit that protects variousparts of the system, including the thyristor rectifier 26).

24 Changeover switch for air--arc gouging, in the form of a three--position switch onthe front panel, which also controls selection of MMA and TIG welding.(See 22).)

25 Main transformer (three--phase).

26 Thyristor rectifier.

27 Basic current resistor, 8.6 τ ±5%.

28 Basic current rectifier.

29 Freewheel diode.

30 Shunt for measurement of welding current.

31 Inductor for smoothing welding current.

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BLOCK DIAGRAM, LHF 630/800

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COMPONENT DESCRIPTION, CIRCUIT DIAGRAM

K1 Main transformer

K2.1 Main thyristors

K2.2 Main diodes

K2.3 Basic current diodes

K2.4 Freewheel diode

K6 Mains switch

K11 Mains terminal block

K12 Inductor

K13 Welding current terminals

K14 Basic current resistor, 8.6 τ ±5%.

K18 Shunt -- 120 mV at 630 A (LHF 630) and at 800 A (LHF 800).

K24 Remote control socket

K27.1 Transient protection

K27.3 Capacitor 0.1←F

K27.4 Capacitor 5←F

K28 Fan

K31 Thermal overload cutout: breaks at 68˚C, resets at 59˚C, tolerance ±3˚C.

K33 LOCAL/REMOTE control selector switch

K38 Indicating lamp, 28 V.

K45.1 Contact, 15--way, male

K45.2 Contact, 15--way, female


K45.4 Contact, 12--way, female


K45.6 Terminal block

K47 Starting capacitor for cooling fan, 3←F 400 V.

K50 Terminal block

K52 Control power supply transformer, supplied at 35 V from K1s3. The secondarywinding supplies 19 V AC to circuit board K70.

K57 Potentiometer (2 kτ) for controlling the welding current. Fine--resolution type,fitted with planetary reduction gear.

K70 Main control circuit board

K79 Selector switch, TIG/MMA/Air--arc gouging.

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CIRCUIT DIAGRAM, LHF 630/800

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DESCRIPTION OF OPERATION, CIRCUIT BOARD K70

This description refers to the circuit diagram on page 14. The same reference numbers thatwere used in the block diagram on page 7 are also used in the description of the circuitboard.

1 Reference input.Reference potentiometer K57 (2kτ ±10% 2W, linear) is supplied at +15V andconnected to A2, A4 and A5.The reference voltage is limited to 0--10V by potential divider R3/R4, and connectedto analog switch IC1.

2 Remote control device.The remote control device, which can be a potentiometer or a pulse generator, isconnected to circuit board terminals A10, A11 and A12 via remote control input K24.

It is supplied at 15 V via pins F and H in input K24. The reference voltage from theremote control device is connected to pin G.0 V between G and H results in minimum current, and 15 V gives maximum current.

3 A/D converter.The A/D converter and the voltage reference unit (see 4), below) are galvanicallyisolated from the rest of the control circuitry by optocoupler IC12 (see 5), below).The A/D converter converts the reference signal to a pulse train, in which themark/space ratio represents the magnitude of the reference signal.

Optocoupler IC12 transfers the pulse train to the D/A converter, thus ensuringcomplete galvanic isolation between the voltage signal from the remote control inputand the other electronic equipment.

If selector switch K33 is in the REMOTE position, but no remote control device isconnected, the power source will give low welding current, as R112, in the A/Dconverter 3), produces a low value of current reference signal.

4 Galvanically isolated voltage reference.The secondary output voltage from winding K1s3 on the main transformer supplies 35V to control power supply transformer K52. The secondary voltage from K52supplies 19 V to remote control output voltage regulator VR1 via terminals B6 and B7and diode bridge BR1.

The output voltage from VR1 is 16.2 V, which is reduced to 15.6 V after diode D12.The regulator is current--limited to 120 mA by resistors R104--107, transistor Q19 anddiode D12, making the remote control connection short circuit--proof.

5 The D/A converter, which recreates the mean value of the reference signal from thepulse train from 3). The input signal is first amplified and filtered: trimmingpotentiometer R87 adjusts the output signal from IC4:1 to 0 V when the remotecontrol potentiometer is at its minimum position and to +11.5 V when thepotentiometer is at its maximum position. The signal is then passed to analog switchIC1, which is controlled by the LOCAL/REMOTE selector switch.

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6 LOCAL/REMOTE selector switch.Three analog switches (IC1) control signal switching for selection of local (internal)or remote (external) control of the welding current.These switches are, in turn, controlled by selector switch K33. The control voltage,which can be measured at terminal A3, is either 0 V ((K33 closed = internalreference) or about +27 V (K33 open = remote reference).

IC1 contains four identical analog switches, of which three are used for local/remotechangeover switching. The fourth switch is used for selection of the Hot Startfunction. The switches conduct with a control voltage of +15 V on pins 6, 12 and 13,and are open--circuit with a control voltage of 0 V.

15 Control power supply.The control power supply is obtained from winding K1s3 on the main transformer,which is connected in star. The voltage between the star point and the respectivephase terminals is about 19 V, and the star point is connected to B5, which is theneutral in the electronic circuitry.The phase voltages are connected to B10, B11 and B12: capacitors C51, C52 and C53decouple any HF interference.

Resistors R125--127 are film resistors that protect the synchronising winding againstany short circuits on the circuit board. Together with capacitors C54--C58, they alsofilter out transient peaks in the 19 V supply caused by the thyristors firing.

Voltage regulator VR2 produces a +15 V stabilised voltage: trimming potentiometerR129 provides fine adjustment. Resistors R128 and R130 restrict the range overwhich the voltage can be adjusted to a maximum voltage of +18 V, which is themaximum permissible supply voltage for the CMOS circuits.

D21 stabilises the negative voltage to --15 V. The power rating of R131 is such as toallow the circuit to supply a load current of 30 mA.

17 The trigger unit converts the DC signal from the control amplifier 16) to ignitionpulses that fire the thyristors at the correct point in the cycle.

The unit consists of three identical sections, one for each thyristor. A synchronisingwinding K1s2, connected to terminals B13--15, provides synchronising informationfor correct firing. The voltage between B13/B14/B15 is approximately 35 V.

The ignition pulses are connected to each thyristor. The gate connections are twistedtogether with the associated neutral connections in order to minimise the risk ofinterference in the gate circuit.

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18 The thermal overload switch interrupts the power supply to output transistors Q9, Q12and Q15 in the trigger unit in the event of excessive thyristor temperature. The switchinterrupts the circuit at a temperature of 68 ˚C, and resets automatically when thetemperature has fallen to 59˚C.

Operation of the thermal overload switch prevents the thyristors from receiving anytrigger pulses. The current flowing in the main welding circuit is then limited to thebasic current of 8 A.

19 The shunt amplifier amplifies the voltage signal from the shunt. Trimmingpotentiometer R132 adjusts the output voltage from the amplifier to --20 mV when nowelding current is flowing.The shunt provides an output voltage signal of 120 mV for 630 A welding current inLHF 630 and 120 mV for 800 A welding current in LHF 800.

22 The MMA/TIG selector switch.Changeover between MMA and TIG welding modes is controlled by transistor Q16,which is controlled by switch K79.In the MMA welding mode, the control voltage at A1 is about --25 V (switch K79open), while in the TIG welding mode it is 0 V (K79 closed).

24 Air--arc gouging/MMA changeover.A contact on switch K79 links contacts A9--A12 in the galvanically isolated remotecontrol circuit to change the operating mode to air--arc gouging. (Switch K79 alsoselects MMA or TIG welding modes.)Optocoupler IC11 is activated in the air--arc gouging mode, and in turn activates theair--arc gouging control circuits.

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CIRCUIT DIAGRAM, CIRCUIT BOARD K70

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COMPONENT POSITIONS, CIRCUIT BOARD K70

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REPLACEMENT OF THYRISTORS

When fitting replacement thyristors, it is extremely important that they are correctly secured,i.e. with a clamping force of 4500 N (450 kp) ±10% for LHF 630 and 5490--5530 N forLHF 800.

Clean the flat surfaces of the thyristors and heat sinks carefully, and remove any burrs ortraces of grease or oil. Apply a very thin film of silicone grease to the contact surfaces of theheat sink, and position the thyristor between the surfaces with the symbol on the thyristorfacing in the direction as shown in the diagram below. Centre the thyristor by locating thepin projecting from the pressure cap in the depression in the thyristor body.

Start by finger--tightening the nuts enough to remove play between the nuts and washers.Then, using a dial gauge or depth gauge, measure the distance from the plate to the spring asshown in the diagram below.Tighten the nuts alternately with a spanner until the distance has decreased by 0.9 ±0.05 mmfor LHF 630 and 1.0 ±0.05 mm for LHF 800.

FITTING OF THYRISTORS

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INSTRUCTION MANUAL

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WARNING

READ AND UNDERSTAND THE INSTRUCTION MANUAL BEFORE INSTALLING OR OPERATING.

ARCWELDING AND CUTTING CAN BE INJURIOUS TO YOURSELF AND OTHERS. TAKE PRECAU-TIONS WHENWELDING. ASK FOR YOUR EMPLOYER’S SAFETY PRACTICES WHICH SHOULD BEBASED ON MANUFACTURERS’ HAZARD DATA.ELECTRIC SHOCK -- Can killS Install and earth the welding unit in accordance with applicable standards.S Do not touch live electrical parts or electrodes with bare skin, wet gloves or wet clothing.S Insulate yourself from earth and the workpiece.S Ensure your working stance is safe.FUMES AND GASES -- Can be dangerous to healthS Keep your head out of the fumes.S Use ventilation, extraction at the arc, or both, to keep fumes and gases from your breathing zone and the general area.ARC RAYS -- Can injure eyes and burn skin.S Protect your eyes and body. Use the correct welding screen and filter lens and wear protective clothing.S Protect bystanders with suitable screens or curtains.FIRE HAZARDS Sparks (spatter) can cause fire. Make sure therefore that there are no inflammable materials nearby.MALFUNCTION -- Call for expert assistance in the event of malfunction.

PROTECT YOURSELF AND OTHERS!

LHF 630 and LHF 800 -- two thyristor controlled welding rectifiers with mains voltagecompensation designed for hand welding, TIG welding and arc--air gouging. The mains voltagecompensation ensures constant welding current and arc voltage regardless of mains voltagevariations. The electronic control circuitry maintains pre--set welding current value. A singlesetting knob takes care of the entire welding current range. All LHF rectifiers are provided withtwo sturdy lifting eyelets facilitating transport by crane, shop traveller or lifttruck.

Hand weldingLHF 630 and 800 have excellent striking and welding properties. The open circuit voltage anda well balanced current boost, i.e. a start surge, facilitate striking and restriking of the electrode.The LHF ”anti--stick” action greatly reduces the risk of the electrode sticking to the workpiece,the welding current is quickly reduced to 8A (the basic current level), which makes it easy toseparate the electrode from the workpiece. This function primary facilitates the welding of rootruns and saves electrodes. The dynamic characteristics of the LHF produce a quiet andspatter--free arc and an easily controlled molten pool. LHF accepts all hand welding electrodes,including basic electrodes.

TIG weldingLHF 630 and LHF 800 are designed with optimal TIG welding characteristics. When TIGwelding thin plate, low min. current is required. LHF’s min. current of only 8A definitelymeets this demand. When TIG welding, the ”start surge” and the ”antistick” action isdisconnected by the switch located on the front panel. Suitable, optimal accessory TIGequipment includes: auxiliary transformer, SEIRION DC or TIG--Aid, gas bottle, gas regulator,TIG--torch, etc.

Arc-air gougingThe LHF 630/800 have been optimized for hand welding and arc--air gouging. Arc--air gougingis not only a way of removing welding defects, it can also be used for the preparation of rootruns and for other forms of weld preparation. It is also an efficient and profitable method ofcleaning up and removing faults from castings as well as cutting off steel reinforcements inconcrete castings. The LHF can be used with carbon rods with diameters of up to 10 and 13 mm,respectively. Compressed air and a torch are needed together with the LHF when arc--air gouging.

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THE ADAPTABILITY OF LHF TO YOUR WORKSITE

LHF is available with spacer bars, solid rubber wheels, pneumatic tyres and a four--wheelchassis -- all according to your particular requirement. With the spacer bars the rectifier canbe used as a stationary unit. The LHF also becomes ”stackable” when provided with spacerbars, i.e. one machine can be placed on top of the other. The pneumatic tyres facilitatetransport on uneven or soft surfaces and the four--wheel chassis can often eliminate the use ofa lifting device. To feed TIG add--on units such as the ESAB TIG--aid, the LHF rectifier canbe fitted with a 24V, 150V A auxiliary transformer. ESAB driers can also be connected to thistransformer. If you want to change your LHF to fit e.g. a new work--site, the above mentionedequipment can be ordered in component sets. In addition, remote control units, hot--start,long--pulse units and connection cables are available upon request.

Remote control unit PHB 1

A light--weight and easy to use one--hand unit, featuring a planetary gear for accurate setting.

Remote control unit PHB 2

Heavy--duty design, featuring steplessly course and fine setting for accurate adjustment.Heavy--duty design, featuring stepless coarse and fine welding current setting from minimum.By limiting the maximum current the fine setting becomes more sensitive.

Remote control unit PHC 2

Robust design with the working range of the machine divided into 10 sectors (in 10 steps).Fine adjustment gives extremely accurate settings within each sector.

Pulse unit PHA 5

When a pulsating current for TIG welding is required, or when welding stainless steel, aPHA 5 can be connected to the LHF rectifier. The current pulse can be set between 0.3 and 2or 4 seconds duration. The pulse current is continually variable between the LHF rectifier’sminimum and maximum current settings.A switch giving continuous current enables the PHA 5 to be used as a remote control unit.Long pulse unit PHA 4 can not be used with LHF rectifiers.

Hot--start unit PHA 2

When combining the LHF rectifier with a PHA 2, the operator can choose between twoentirely independent current levels. The selector for these two levels is mounted on theelectrode holder. This is used, for example after switching electrodes in one--side weldingwith a backing piece. The higher current is then selected, which melts down welding faults(pipes and cratercracks, etc.) which often occur when welding is interrupted. The two currentlevels can be set independently.

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OPERATION

All LHF controls are located on the front panel. These include ON and OFF switch, indicatorlight, toggle switch for TIG or hand welding and arc--air gouging, setting knob for weldingcurrent, switch for with or with--out remote control unit, and a socket for the remote controlunit. The sockets for connection of welding cable and ground return cable connectors arelocated below the front panel and the grille.

Starting instructions

1. Turn the switch to the ”I” position. The indicator lamp will light up and the fan will start.

2. Make sure that the air inlet is not blocked.

3. Set the toggle switch for TIG welding, hand welding or arc--air gouging in correct posi-tion.

INSTALLATION

The LHF rectifiers are reconnectable for220/380/415/500 V 50 Hz -- 220/440/550 V 60 Hz.

1. Make sure that the rectifier is correctly wired for the mains voltage available. You cancheck this by comparing connection block K11 with the connection drawings on the cir-cuit diagram.

2. Mains cable area and fuse size, see table on next page.

3. The mains cable is connected to terminals R, S and T on the connection block K11.Phase sequence is of no importance. Cable lead--in and stress--relieving clamp are locatedat the very bottom left on the back of the rectifier.

4. Ground. The rectifier must be grounded in accordance with relevant regulations.

Ground to be connected to bolt marked next to the connection blocks above themain transformer.

5. Welding and ground return cables.The conduit area (Cu) of the LHF 630 should be 70 mm2 and 120 mm2 for LHF 800.When welding with exceptionally long cables, it may be necessary to use cables of largerdimensions in order to limit voltage drop and maintain stable arc voltage. Make sure thecables are properly connected to the cable connectors, electrode holder, and groundclamp.

6. Connection of auxiliary transformer for TIG add--on unit, or electrode drier. Remove theplastic plugs at the very bottom right of the back plate. The auxiliary transformer isplugged in by connecting the wires to connection block K50 (see circuit diagram en-closed with the auxiliary transformer).

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TECHNICAL DESCRIPTION

The LHF rectifiers consist of one power unit and one control unit. The fan--cooled power unitcomprises the main transformer, a rectifier bridge, an inductor, a basic current circuit, acooling fan, terminal blocks for voltage change--over, mains connection and the mainsconnection switch. The control circuit constitutes an enclosed dust-- proof area located at thefront of the power source, which is screened off from the ventilated power unit. The controlunit includes a potentiometer for current adjustment, a socket for the remote control unitincluding switch, electronic control circuitry, indicator light and a transformer, feeding thephysically separated remote control unit.

Overload protection

The welding rectifier is provided with a thermal cut--out, which protects the equipmentagainst overheating caused by overloading or insufficient cooling. The thermal cut--out is dustand moisture proof.The thermal cut--out is located on the heat sink close to the semi-- conductors and isautomatically re--set when the power unit has cooled down sufficiently.

Control unit

The control unit is dust--proof. The front plate, on which the controls are located, is easilyremoved by means of four snapcatches with quarterturn locking action. The control unitincludes the current setting potentiometer with planetary gear. This gear has built--in safetyclutch, which provides improved welding current adjustment and eliminates the risk ofmechanical potentiometer damage. The control unit comprises a single, printed electroniccircuit card with gate connection wires provided with flat pin--plugs and two unmistakableplug--in couplings. The entire circuit card has been dipped twice in a special, protectivepolyurethane type lacquer. When using a remote control unit, a physical separation betweenthe remote control potentiometer signals and the control amplifier is made. This willeliminate problems, such as creeping current in humid weather, break--down due to pinchedcontrol cable, and it will also prevent external interference from penetrating the electroniccircuitry.

TECHNICAL DATA

LHF 630 LHF 800

Permitted loadat 35% duty factorat 60% duty factorat 100% duty factor

630A/44V500A/40V400A/36

800A/44V630A/44V500A/40V

Setting range 8A/20V -- 630A/44V 8A/20V -- 800A/44V

Open--circuit voltage 65 -- 72V 69 -- 76V

No--load rating (kW) 0,6 0,65

Power factor (↔)at 150A/ at max A 0.56 / 0,87 0,52 / 0,82

Weight, approx. 235 kg 275 kg

Efficiency (♣) 0,71

Temperature class H (180C)

Design criteria IP 23 AF

Class of use K

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Mains connection LHF 630 50/60 Hz 50 Hz 50 Hz 60Hz 50 Hz 60 Hz

Voltage (V) 3x220 3x380 3x415 3x440 3x500 3x550

Current (A) 70 40 37 37 31 31

Fuse, slow (A) 80 50 50 50 35 35

Cable area (mm2) 4x25 4x10 4x10 4x10 4x6 4x6

Fuse, fast (A) 100 63 63 63 63 63


Mains connection LHF 800 50/60 Hz 50 Hz 50 Hz 60Hz 50 Hz 60 Hz

Voltage (V) 3x220 3x380 3x415 3x440 3x500 3x550

Current (A) 92 53 49 49 40 40

Fuse, slow (A) 100 63 63 63 50 50


Fuse, fast (A) 125 80 80 80 63 63


Note! Primary currents refer to a 100 Β duty cycle.Cable areas according to Swedish regulations.

Mains voltage -a mains voltage variation of 10Β gives a compensation welding currentvariation of only0.2Β.

Standards comply with: VDE 0542, ISO R700, SEN 8301, NF A 85--011

MAINTENANCE

LHF 630 and LHF 800 require a minimum of maintenance and service. Under normaloperating conditions, the machine should be blown clean with compressed air at reducedpressure once a year. When used in dusty or dirty areas, the machine must be blown cleanmore often.

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STATIC CHARACTERISTICS

Arc-air gouging

LHF 630 LHF 800

= standardized load voltage as per ISO R 700, VDE 0542

EFFICIENCY ç AND POWER FACTOR ë

LHF 630 LHF 800

U2 = standardized load voltage

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DIMENSION DRAWING

Stationary type

With solid rubber wheels

-- 27 --sparefram

SPARE PARTS LIST LHF 630/800

Spare parts list - Reservdelsförteckning - Ersatzteilverzeichnis - Liste de pièces détachées

Spare parts are to be ordered through the nearest ESAB agency as per the list on the back of thecover. Kindly indicate type of unit, serial number, denominations and ordering numbers according tothe spare parts list.

Reservdelar beställs genom närmaste ESAB--representant, se sista sidan. Vid beställning var vänliguppge typ och tillverkningsnummer samt benämningar och beställningsnummer enligtreservdelsförteckningen.

Die Ersatzteile können bei der nächsten ESAB--Vertretung bestellt werden, siehe letzte Seite.Bitte geben Sie Typenbezeichnung und Herstellungsnummer sowie Bezeichnungen undBestellnummern laut Ersatzteilverzeichnis an.

Au dos de la brochure, vous trouverez l’adresse du représentant ESAB le plus proche. Prière de luiadresser votre commande, après avoir pris le soin de mentionner le type et le numéro de série del’unité ainsi que le numéro de commande et la désignation conformément á la liste de piècesdétachées.

Reservdelsförteckning -- Spare parts list -- Ersatzteilverzeichnis -- Liste de pècees détachèes

-- 28 --cmja0se1

630 = LHF 630 (220 V -- 550 V) 800 = LHF 800 (220 V -- 550 V)

ItemQty630

Qty800 Ordering no. Denomination Remarks

Componentdesignationin the circuitdiagram

101 1 1 2188 106--02 Indicator (K57)

102 1--

--1

466 937--001466 940--001

Front panelFront panel

103 11

--1

147 866--001193 219--001

SwitchSwitch Offshore

K33K33

104 1 1 321 497--001 Top cover

105 2 2 321 001--001 Ring

106 -- 1 467 230--002 Side panel LHF 800

107 1 -- 467 229--002 Side panel LHF 630

108 1 1 320 939--001 Holder

109 2 2 365 038--001 Wheel

110 1 1 365 046--001 Axle

111 6 6 2157 010--19 Circlip

112 2 2 320 023--001 Support beam

113 2 2 319 738--001 Foot

114 2 2 319 455--002 Rubber damper

115 3--

--3

160 362--881160 362--882

Welding receptacleWelding receptacle

K13K13

116 2--

--2

160 360--882160 360--883

Cable connectorCable connector

117 1 1 367 972--005 Sleeve in socket K24

118 1 1 368 544--003 Remote socket

119 -- 1 467 230--001 Side panel LHF 800

120 1 -- 467 229--001 Side panel LHF 630

121 1 1 320 939--002 Holder

122 2 2 321 000--001 Handle

123 2 2 2188 012--01 Rubber grip

124 1 1 318 113--004 Control knob (K6)

125 11

--1

147 866--002193 219--002

SwitchSwitch Offshore

K79K79

126 1 1 192 576--003 Indicator lamp K38

127 1 1 368 120--001 Connection diagram

128 1 1 2188 107--84 Knob (K57)


-- 29 --cmja0se1


-- 30 --cmja0se1

630 = LHF 630 (220 V -- 550 V) 800 = LHF 800 (220 V -- 550 V)

ItemQty630


Component des-ignation in the cir-cuit diagram

201 11

11

319 876--880319 876--881

Printed circuitSubstitute printed circuit *)

K70+K45.1 + K45.4K70+K45.1 + K45.4

202 1 1 192 784--016 Socket 15 pole K45.2

203 22 22 192 784--101 Pins for plugs K45.1, andK45.3

204 1 1 192 784--014 Socket 12 pole K45.4

205 1 1 192 784--013 Plug 12 pole K45.3

206 22 22 192 784--102 Insert for sockets K45.2and K45.4

207 1 1 319 828--001 Control transformer K52

208 1 1 320 131--880 Grille

209 4 4 2121 086--49 Locking screw M6x12

210 4 4 365 958--001 Anti--locking washer

211 1 1 192 724--007 Potentiometer K57

212 1 1 317 942--001 Planetary gear (K57)

213 1 1 192 753--006 Connection block 6 pole K45.5

214 1 1 192 784--015 Plug 15 pole K45.1

215 2 2 365 745--001 Holder, Peb

*) To obtain this circuit card the old card must be returned.


-- 31 --cmja0se1


-- 32 --cmja0se1

630 = LHF 630 (220 V -- 550 V) 800 = LHF 800 (220 V -- 550 V)

ItemQty630


Componentdesignationin the circuitdiagram

301 1--

--1

191 085--103191 085--106

CapacitorCapacitor

K47K47

302 1 1 5231 041--02 Connection block 3-pole K50

303 1 1 0407 055--01 Connection block K14

304 3 3 192 716--004 Silicon diode K2.3

305 1 1 5231 041--05 Connection block 12- pole K45.6

306 1 1 319 837--004 Rear panel

307 1 1 319 838--001 Fan casing

308 1--

--1

162 430--001162 430--002

FanFan

K28K28

309 1 1 162 548--005 Series resistor K14

310 2 2 317 660--001 Element rod K14

311 1--

--1

319 944--880319 944--881

InductorInductor

K12K12

312 3--

--3

319 928--880319 928--881

CoilCoil

(K12)(K12)

313 2 2 0408 940--01 Main connection block K11

314 11--

----1

319 947--892319 947--894319 947--895

Main transformerMain transformerMain transformer

OffshoreOffshore

K1K1K1

315 1--

--1

319 973--881319 968--880

Coil, main transf.Coil, main transf.

(K1)(K1)

316 1 1 192 884--002 Capacitor K27.4

317 1 1 320 745--003 Circuit switch K6

318 1--

--1

319 690--882319 932--880

Thyristor bridgeThyristor bridge

K2.1K2.1

319 2 2 192 883--003 Capacitor K27.3

320 1 2 4906 006--06 Diode K2.4

321 3 6 4906 006--26 Silicon diode (K2.2)

322 1--

--1

319 904--880319 923--880

Diode bridgeDiode bridge

K2.2K2.2

323 1--

--1

319 911--880319 911--881

ShuntShunt

K18K18

324 1 1 319 999--001 Thermostat K31

325 3--

--3

319 690--883319 932--881

Tensioning deviceTensioning device

326 3 3 0410 516--06 Transient protector K27.1

327 3--

--3

320 028--001318 726--001

ThyristorThyristor

(K2.1)(K2.1)

328 1 1 191 309--112 Cable clamp

329 1 1 192 041--139 Cable grommet


-- 33 --cmja0se1

ESAB Welding Equipment ABSE--695 81 LAXÅSWEDENPhone +46 584 81 000Fax +46 584 123 08

www.esab.com

001004

ESAB subsidiaries and representative offices

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