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n6.2400 g-v n6.2900 g-v n7.3600 g-v n7.4500 g-v operating instructions for specialist installation engineers gas burners 2-25 en de fr 4200 1032 1400 it nl 4200 1032 1500 4200 1032 0000 10/2010 art nr 4200 1032 1300a

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overview contents contents 2 important information 2 burner description 3 operation gas start-up mode gas operating mode 4 general safety functions 4 equipment options 5 automatic furnace controller lfl 1 lgk 6 gas valve vgd with skp actuator 7 gas valve mbc-vef 7 assembly boiler lining for g-v burner burner assembly 8 gas connection 9 gas manifold pressure take-off pipes 10 checking assembling the combustion components11 gas connection electrical connection 12 checks before commissioning 12 commissioning working cycle test firing 13 safety unit settings and checks 13 actuator limit switch setting 14 flame sensor 15 gas pressure switch air pressure switch 16 gas valves and instruments group description 17 basic construction 17-19 gas valve leakage controller 20 servicing maintenance 21-22 exhaust gas test trouble shooting instructions 23-24 operating trouble 25 important information n6 and n7 g-v burners are designed for the low-polluant combustion of natural gas the design and function of the burners meet standard en 676 they are suitable for use with all heat generators complying with standard within their respective performance range any other type of application requires the approval of elco installation start-up and maintenance must only be carried out by authorised specialists and all applicable guidelines and regulations must be complied with burner description n6 and n7 g-v burners are modulating pneumatic fully automatic monoblock devices emissions values may differ depending on combustion chamber dimensions combustion chamber load and the firing system three-pass boilers boilers with reverse firing for specifying warranty values the conditions for the measuring equipment tolerances and humidity must be observed packaging the burner is supplied packaged in three boxes on a pallet burner body with integrated switch cabinet flange seal and securing screws operating instructions circuit diagram and spare parts list combustion head compact gas train with integrated or external filter the following standards should be observed in order to ensure safe environmentally sound and energy-efficient operation en 226 connection of fuel oil and forced-draught gas burners to a heat generator en 60335-1 -2-102 specification for safety of household and similar electrical appliances particular requirements for gas burning appliances gas lines when installing the gas lines and trains the general directives and guidelines as well as the following national regulations must be observed ch g1 instruction text from ssige ekas form no 1942 liquefied gas directive part 2 cantonal authority guidelines e.g directives for the pilot valve de dvgw-tvr/trgi installation location the burner must not be used in rooms with aggressive vapours e.g hair spray tetrachloroethylene carbon tetrachloride high levels of dust or high air humidity e.g laundry rooms if no connection to an air exhaust system is provided for the air supply there must be a supply air inlet measuring de up to 50 kw 150 cm 2 per additional kw 2.0 cm 2 ch qf [kw x 6 cm 2 but at least 200cm 2 variations may arise as a result of local regulations overview declaration of conformity for gas burners we elco burners gmbh herbertliebsch-straße 4a 01796 pirna germany declare under our sole responsibility that the products n6.2400 g-v n6.2900 g-v n7.3600 g-v n7.4500 g-v conform to the following standards en 50165 en 12953-7 en 12952-8 en 61000-6-2 en 61000-6-4 en 676 these products bear the ce mark in accordance with the stipulations of the following directives 2006/42 /ec machinery directive 2004/108/ec emc directive 2006/95/ec low voltage directive 2009/142/ec gas appliances directive 97/23/ec pressure equipment directive pirna 26th may 2010 d hoffmann we accept no responsibility for damage arising from inappropriate use incorrect installation and/or repair on the part of the buyer or any third party including the fitting of non-original parts final delivery and instructions for use the firing system fitter must supply the operator of the system with operating and maintenance instructions on or before final delivery these instructions should be displayed in a prominent location at the point of installation of the heat generator they should include the address and telephone number of the nearest customer service centre notes for the operator the system should be inspected by a specialist at least once a year depending on the type of installation shorter maintenance intervals may be necessary it is advisable to take out a maintenance contract to guarantee regular servicing 2 10/2010 art nr 4200 1032 1300a

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overview burner description 2 5 6 7 8 10 11 13 19 f6 m1 y10 pf power controller option housing gas inlet flange gas damper manual adjustment burner flame tube integrated electrical cabinet burner fixing flange air intake box hoisting eyes air pressure switch blower motor actuator for air damper furnace pressure take-off tube en 10/2010 art nr 4200 1032 1300a 3

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operation gas start-up mode gas operating mode general safety functions gas start-up mode as soon as the furnace system is required to supply heat the burner control circuit will close and the program flow started when the program has come to its end the burner will be turned on an automatic test is made for the tightness of the gas valves prior to each burner start the air damper is in its closed position when the burner is out of operation the electric actuator will open the closed air damper to its full-load position so that the burner will ventilate the furnace and the exhaust hoods with the specified air rate shortly after the pre-ventilation process has been started the lack-of-air cut-out must change over to operating position within a certain time i.e the minimum air pressure setting must be reached and maintained until the burner is turned off at the end of the specified pre-ventilation time the air damper will be moved into its partial-load position in a linked control concept with the gas damper the ignition transformer is activated after the pre-ignition time the main gas valves are open and the gas comes out from injectors where it is mixed in the combustion head with air coming from the fan the ignition of the gas air mixture is done directly by a high voltage spark on a gas injector during the safety time a stable flame is formed and is monitored by an ionisation sensor the ignition is stopped before the end of the safety time and the burner operates at its minimum power the start-up programme is completed gas operating mode after the flame has developed the load regulator will be enabled which brings the burner into its operating position the load regulator will now control the burner automatically between its partialload and full-load stages depending on the heat demand the electric actuator of the compound control system will be fed with the open or close command via the regulator and thus increase or decrease the gas and air flow rates this compound control system will vary the positions of the gas control valve and air damper and thus regulate the gas flow rate in a linked concept with the air flow rate the burner can either be controlled by a 2-stage sliding or if a respective controller is provided a stepless control concept the stepless control will allow the burner to be operated at any desired stage between its partial-load and fullload positions the air damper will be closed when the burner is out of operation and will thus prevent cold air flowing through the burner chamber heat exchanger and chimney the interior cooling losses will thus be greatly minimized attention if there are shut-off dampers in the flue gas tract they must be complete open otherwise there will be a high danger of low-speed detonation or explosion the open-position of the shut-off damper can be assured by the integration of the opening contact of the shut-off damper in the safety chain of the heat generator gas control 2-stage sliding full load operating position load regulator release partial load stepless full load operating position load regulator release start load partial load ignition/gas valves ignition/gas valves on off on off general safety functions in case a flame does not develop when starting the burner fuel release the burner controller will shut off at the end of the safety period shut-off on trouble a shut-off on trouble will also occur in the case of flame failure during operation air flow failure during the preventilation phase and pressure failure during the whole period of burner operation any failure of the flame signal at the end of the safety period and a flame signal during the pre-ventilation phase external light control will result in a shut-off on trouble with the automatic furnace controller being locked 4 the trouble is indicated by the trouble signal lamp lighting up the automatic furnace controller can be unlocked immediately after a shut-off on trouble by pressing the unlocking key the program unit will return to its starting position and proceed with the restart of the burner a voltage failure will result in a regular shut-off of the burner after voltage recovery the burner can be automatically restarted unless another interlock is active e.g one caused by the safety circuit in any case the fuel oil supply will be immediately stopped upon occurrence of a trouble 10/2010 art nr 4200 1032 1300a the control unit will stop at the same time causing also the trouble location indicator to stop the symbols will indicate the kind of trouble.

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operation equipment options please note the gas outlet pressure gas regulating pressure must always be less than the gas inlet pressure but higher than the total pressure loss of the system equipment option speed control the burners can be equipped with a speed controller as an option during long burner operating periods in the partial load range in particular the reduction in blower speed helps to conserve electrical energy and reduce noise emissions from the burner blower itself the speed of the blower is measured by a namur sensor and controlled to the programmed reference value for the current output level equipment option o2 control co control to improve the efficiency of the system the combustion manager can be equipped with residual oxygen or co control co control available only with the use of a lamtec burner controller the residual oxygen is measured in the flue gas of the heating system by an o2 measuring probe with zirconium oxide sensor and sent to the combustion manager as a correction factor thanks to o2 control it is possible to eliminate variations in ambient conditions e.g combustion air temperature and humidity calorific value fluctuations etc and significantly reduce the air surplus required for calibration reference value deviations are controlled by corrections to the blower speed or the air flap position with the use of co control only possible with gas operation the co content is measured in addition to the residual oxygen the air surplus is reduced to the co edge by a correction to the blower speed or the air flap position the correction factors are determined in a systemspecific learning process and stored temporarily in the combustion manager this makes it possible to maximise the system s heating efficiency across the entire output range and optimally manage the combustion process for further information please refer to the manufacturer s documentation for the electronic combustion manager en 10/2010 art nr 4200 1032 1300a 5

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o per i at on a ut atc f nace cont oler lfl 1 lg k om i ur r l the lfl 1 lgk type controller is designed to control and monitor burners working according to a stepwise or modulating principle a detailed functional description with technical data and project planning information with respect to the automatic combustion controllers can be found in the annex and in the documents lfl 1 7451/lgk functional diagram lfl 1 lgk a starting type interval a-b flame development interval b burner has reached operating position b-c burner operation heat generation c-d regular shut-off t1 pre-ventilating time t2 safety time t3 pre-ignition time t4 fuel valve enable t5 load regulator enable t6 post ventilation time t7 start delay interval for ventilation motor t11 open run time of air damper t12 close run time of air damper t13 permissible afterburn time r temperature or pressure controller m fan motor z ignition transformer bv fuel valves lr lk rv fs load regulator air damper steadily adjustable fuel valve signal of flame 6 10/2010 art nr 4200 1032 1300a

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o per i at on g as val vg dwih sk p act or ve t uat g as val m b c ve vef 1 2 3 4 5 6 7 8 gas ball valve option filter under the cover gas manometer with push button upstream option test burner with push button option actuator skp 15 actuator skp 75 gas main valve vgd gas manometer with push button downstream option en technical data input pressure 360 mbar max ambient temperature -15 to +50°c voltage 230 v 50 hz max protection rating ip 54 1 2 3 4 5 8 gas ball valve option filter under the cover gas manometer with push button upstream option test burner with push button option compact gas train safety valve main valve gas manometer with push button downstream option technical data input pressure 360 mbar max ambient temperature -15 to +50°c voltage 230 v 50 hz max absorbed output in operation 250 w max protection rating ip 54 10/2010 art nr 4200 1032 1300a 7

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assembly boiler lining for g-v burner burner assembly boiler lining the burner lining must be installed rightangled to the burner tube possible trimming work bevelling rounding as required for reverse boilers for example should done at a diameter not below 70 of the combustion chamber diameter the space between the flame pipe of the burner and the boiler lining should be lined with heat resistant material such as cerafelt this space is not allowed to be lined with brickwork d see dimensioned drawings d1 see dimensioned drawings df combustion chamber diameter t1 80 mm t depth of boiler lining option extensions see technical data note for reverse flow boilers for reverse flow boilers the dimension t1 is only a recommended value depending on type of boiler the burner head must stand at least 50 mm ahead the opening for flue gas turning back burner assembly · take the burner tube delivered in a separate box · fit it on burner body · remove cover · tighten the 2 fixing screws s1 · lift the burner using the 2 hoisting eyes 19 see page 3 and fasten to the boiler · tighten the 4 fixing screws s2 · place cover back on 8 10/2010 art nr 4200 1032 1300a

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assembly gas connection gas connection the gas lines and valves and instruments group should be installed and taken into operation in accordance with the applicable engineering standards and regulations the connection between the gas distribution network and the gas ramp must be done by authorised persons the section of the pipings must be calculated so that the loss of load doesn t exceed 5 of the distribution pressure a quarter turn manual valve not supplied must be provided for upstream of the gas ramp and the filter the filter must be installed on a horizontal nozzle with the cover in the vertical position to enable cleaning the threaded unions used must be in conformity with present standards tapered male thread straight female thread with sealing provided in the thread provide for sufficient space to access the gas pressure switch adjustment gas properties prior to any installation work make sure to obtain the following data from the gas supply company 1 type of gas 2 calorific value h un=kw/m³ kj/m³ 3 maximum co2 content of exhaust gas 4 gas connection pressure and rest pressure type of gas test prior to mounting the burner to the gas feed line check the available type of gas and burner type against the data given on the burner nameplate attached to burner be sure the description of the burner and the type of gas are the same as indicated on the nameplate gas connection pressure a minimum connection pressure must be available upstream of the burner gas valve to ensure the proper functioning of the burner for the installation of the valves and instruments group take care to observe the mounting instructions supplied by their manufacturers these are packed with the equipment the gas line installed to the burner must be dimensioned in accordance with the throughput rate and the available pressure for selecting the nominal bore dn of the gas valves and instruments group care should be taken to observe the flue resistance of the boiler and the gas pressure loss of the burner and valves and instruments group caution the absence of impurities and foreign bodies must be checked before installation and commissioning of the gas ramp the lever valves and unions gas valves and instruments group the gas valves and instruments group can be connected directly to the gas feed line take care to observe the correct order of installation and direction of flow arrow on housing check the valves and instruments and connection pieces for absence of dirt particles and foreign matter before installation and initial operation to provide effective conditions for startup make sure the distance between the burner and the gas stop valve is as short as possible leak test the gas line upstream of the burner gas valves and instruments group must be installed in accordance with the applicable regulations checked for absence of leaks vented and certified accordingly by the gas installation company the screwed unions and flanged joints must be checked for proper tightness by making a pressure test the leak test must be made under pressure using approved foaming agents which do not cause corrosion for steam boiler furnaces the result of the leak test must be duly certified venting caution prior to taking the burner into operation or after any repair work make sure to vent the complete gas feed line and the gas valves and instruments group into the open atmosphere e.g by means of a hose taking care to avoid any hazards in no case should the gas line be vented into the heating or furnace chambers make use of a test burner to check the gas-carrying spaces are free from an inflammable gas mixture support the valves and instruments group must be supported with a telescopic jacking member or similar during and after installation e.g on filter and valve joint it is recommended to provide an easytodisconnect joint with planar sealing faces to facilitate repair work on the boiler furnace and allow the boiler door to be swivelled out if required en 10/2010 art nr 4200 1032 1300a 9

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assembly gas manifold pressure take-off pipes gas train assembly · check the correct position of the o-ring in the gas connecting flange · secure the gas train on the burner head so that the gas train coils are in the upper vertical position · pay attention to the direction of circulation · connect the power cable to the gas train connecting pressure take-off pipes pf and pl · connect the furnace pressure take-off tube pl on the burner body and the union pl on the gas train using the tube pl blue shorten the tube depending on the assembly scenario · connect the furnace pressure take-off tube pf on the burner body and the union pf on the gas train using the tube pf shorten the tube depending on the assembly scenario · manually screw in the unions max 5nm and check tightness pbr pg gas pressure take-off tube pf furnace pressure take-off tube pl air pressure take-off tube d setting screw air surplus r setting screw ratio gas/air setting index of the ratio r setting index of the d value 10 10/2010 art nr 4200 1032 1300a

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assembly checking assembling the combustion components burner n6.2400 g-v n6.2900 g-v n7.3600 g-v n7.4500 g-v a 19 0 50 100 b 203 185 234,5 en assembling the combustion components · check that the o-ring j1 is in the correct position in the gas elbow · check the adjustment settings of the ignition electrode as per the diagrams · insert the combustion components into the head tighten the mounting screws s3 · connect the ignition cable zk on the combustion head · connect the ignition cable zk on the ignition transformator t1 important if there is a change to the type of gas used for example h or e natural gas g20 to l or ll gas g25 or vice versa the burner settings should be completely overhauled it is not necessary to modify the combustion head in any way 10/2010 art nr 4200 1032 1300a 11

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assembly gas connection electrical connection checks before commissioning general regulations applying to the gas connection · the gas train must only be connected to the gas mains by a recognised specialist · the cross-section of the gas line should be of a size designed to guarantee that the gas flow pressure does not drop below the specified level · a manual shut-off valve not supplied must be fitted upstream of the gas train · in germany a thermally triggered shut-off valve to be installed by the customer side must be fitted as all electrical installation and connection work must only be carried out by a suitably qualified electrician the applicable guidelines and directives must be observed as well as the electrical circuit diagram supplied with the burner electrical connection · check to ensure that the power supply is as specified 230v 50 hz single phase with neutral and earth boiler fuse 10 a specified by the draft combustion ordinance it is the responsibility of the fitter or his representative to obtain approval for the system at the same time as the burner is commissioned only the fitter or his representative can guarantee that the system meets applicable standards and regulations the fitter should be in possession of the corresponding official permit and should carry out the corresponding sealing tests and purge the system of air electrical connection it must be possible to disconnect the burner from the mains using an omnipolar shutdown device complying with the standards in force burner motor connection the burner is delivered for a power supply of 400v 50hz of triphase current with neutral and earth connect the burner motor cable to the terminals in the electrical cabinet check the direction of rotation of the ventilation motor manually with the burner contactor connecting the gas train connect the gas train to the plugs on the burner checks before commissioning the following must be checked before initial commissioning · that the burner is assembled in accordance with the instructions given here · that the burner is pre-set in accordance with the values in the adjustment table · setting the combustion components · the heat generator must be ready for operation and the operating regulations for the heat generator must be observed · all electrical connections must be correct · the heat generator and heating · · · · · system must be filled with water and the circulating pumps must be in operation the temperature regulator pressure regulator low water detectors and any other safety or limiting devices that might be fitted must be connected and operational the exhaust gas duct must be unobstructed and the secondary air system if available must be operational an adequate supply of fresh air must be guaranteed the heat request must be available sufficient gas pressure must be available · the fuel supply lines must be assembled correctly checked for leaks and bled · a standard-compliant measuring point must be available the exhaust gas duct up to the measuring point must be free of leaks to prevent anomalies in the measurement results 12 10/2010 art nr 4200 1032 1300a

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commissioning working cycle test firing safety unit settings and checks pre-ventilation return to ignition position ignition of electrodes valves open burner stops due to lack of gas pressure or control unit locks because flame is extinguished if unsure redo the above test the unit can only be fired once this very important operating sequence check has been performed firing warning the burner may be only fired when all the requirements listed in previous sections have been met · connect a microammeter scale 0 100 µa dc · open the quarter-turn hand-operated fuel valve · close the thermostatic circuit the leak tester is charged after running the test 30 s the control unit programme will relaunch after preventilation the burner comes on and operates at minimum power · check the following the combustion the overall leak tightness of the gas train using foam designed for this purpose no leaks should be detected · measure the gas flow shown on the counter · slowly increase the power to nominal output controlling the combustion throughout if necessary adjust the combustion by adjusting the pair:pgas pressure ratio screw r · adjust the servomotor control cam i nominal output to limit the maximum opening of the air flap to the position reached for nominal output · slowly reduce the power to the nominal output required checking the combustion values throughout if necessary at minimum power adjust the combustion via parallel shifting of the characteristic screw d · adjust servomotor control cam iii minimum output to limit the minimum opening of the air flap possible during operation to the position reached for minimum output · precautions on principle the nominal output must only be modified by adjusting the pair:pgas pressure ratio screw r and the minimum output must only be modified by offsetting in parallel to the characteristic e screw d · after any modification to the minimum output settings check the combustion at nominal output and adjust if necessary · after any modification to the nominal output settings check the combustion at minimum output and adjust if necessary 10/2010 art nr 4200 1032 1300a · to complete the adjustment process restart the burner and check the power and the combustion if necessary carry out adjustments as described above · check the leaktightness of the gas train · no leakage should be detected · check the safety devices · setting and checking the safety devices gas pressure switch · set it to the minimum distribution pressure · the burner operates at minimum output · slowly close the 90° manual shut-off valve · the burner must stop due to a lack of gas pressure · open the 90° manual shut-off valve · the burner restarts automatically · the pressure switch is set · fix and screw on the cover air pressure switch · see the paragraph entitled determining the differential preventilation pressure and setting the differential pressure switch page 16 leak testing device vps · open pa on the device · restart the burner after 30s the tester should enter safety mode red light on · reclose pa · o unlock the tester safety catch by pressing the red indicator the test cycle is relaunched the burner will be working · check the leaktightness · disconnect the measurement devices · re-close the pressure tap · reset the unit the burner will be working · check the seal between the flange and the boiler front the opening of the control circuit limiter and safety the current on the motor relay · check the combustion under actual working conditions doors closed cover in place etc and check all circuits for possible leaks · establish a measurement protocol · start-up automatic operation · provide all the data required for proper operation inform the boiler room operator · place the boiler plate in a visible location en important before firing to ensure the gas train operates correctly the position of the gas flap must be checked the table below shows the recommended setting depending on the burner burner setting ° 50 mbar 300 mbar n6.2400 g-v 90 45 n6.2900 g-v 90 45 n7.3600 g-v 45 45 n7.4500 g-v 45 45 · if a correction is necessary proceed as follows · loosen screw s · manually move lever h to the recommended position setting according to the table above · lock into position using screw s on the housing mounting bracket pre-setting the skp 75 according to the table below these values are given as a guide only burner n6.2400 g-v n6.2900 g-v n7.3600 g-v n7.4500 g-v gas shift from pressure pressure origin ratio [mbar screw d screw r 50 0,5 0,9 0,8 300 2,9 4,0 2,2 2,3 50 0,9 1,3 1,4 300 2,9 3,7 2,2 2,3 50 300 50 300 pre-setting the pressure switches on the burner and the gas train see the commissioning gas pressure switch/air pressure switch section checking the operating sequence · open the quarter-turn hand-operated fuel valve then immediately close it again · switch the burner on · select manual operation mode on the control cabinet · close the thermostatic circuit the vps 504 s02 leak tightness test device is switched on after 30 s if the test is validated the amber light will come on the control unit is now powered on the program should function in the following way air flap opens to the servomotor nominal output position 13

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c om m i oni ssi ng a ct or uat li i sw ich set imtt tng important once the pressure switches have been set they must be protected to prevent settings from being altered for example this can be done by placing a spot of varnish on at least one of the screws on the equipment s protective cover once the burner has started up its safety systems must be checked to ensure they are operating correctly likewise following start-up it is necessary to check that the boiler s safety chain is operating correctly in accordance with the regulations in force this check must be carried out with the user s agreement technical data sqm actuator voltage 230 v -15 50 60 hz 240 v +10 50 60 hz power input 9 va max contact load250 v 10 3 a mounting positionas required ambient temperature -20°c 50°c protection classification ip 54 din 40050 weight 1,7 kg sqm10/11 sqm20/21 running time at 130° turning 42 sec 66 sec angle torque 10 nm 20 nm description the sqm actuator is intended for use with two-stage sliding or modulating oil gas or dual-fuel burners the reversible actuator is fitted with a synchronous motor which drives a shaft via a gearbox the shaft end carries a coupling to drive the fuel and combustion air controlling element the sqm actuator has been designed for dual-wire control by controller or switching units with change-over contacts potentiometers can be installed for a range of applications on customer s request the 60 hz frequency will reduce the running times by approx 17 limit switch factory setting description i ii iii iv v 0° pre setting function max power air and gas closed flaps air and gas firing air flow not used cam v gives minimum regulation info must be set between values of cam i and vi set minimum air flowrate simultaneous switch-on of nominal flow indicator and hour counter only for operation hours below nominal flow rate set a few degrees below the regulation flow-rate value of cam i the limit and auxiliary switches are set by means of manually adjustable latching cam plates scales are fitted between the disks to facilitate the selection of the switching points the cam plates are provided with a small pointer for indicating the switching point of a scale between the setting ranges an additional scale fitted to the end of the cam roller serves to indicate the position of the actuator the drive unit may be disconnected from the controlling element by changing over a rocker arm mounted to the gearbox this will allow any desired position of the controller plate to be selected by hand drive and output will be coupled in the vertical position of the rocker arm vi vii positions 1 terminals 2 cam setting key 3 scales for switching point setting 4 rocker arm for uncoupling 5 scale for actuator position 6 actuator position indicator 7 shaft end to fit a return potentiometer 8 power supply cam vi controls minimum automatic flow-rate following ignition if not requested the flow remains unchanged the time-delay unit k6 in the control cabinet must be set at 15 s 14 10/2010 art nr 4200 1032 1300a

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c om m i oni ssi ng flame sensor ionisation monitoring detection of the flame using an ionisation device flame detection is achieved using the conductivity and the rectification effect of the hot flame gases an alternating voltage is applied to the sensor in refractory material which is dipped into the flame when a flame is present the current ionisation current circulates and forms the flame signal this signal is transmitted to the input of the flame signal amplifier the flame signal amplifier is designed to react only to the continuity of the flame signal this eliminates the possibility for confusion of a potential short-circuit between the sensor electrode and earth with a flame signal as an alternating current would be used in this scenario use a microammeter to measure the signal take into account the measurement range this device is placed between the control box and the ionisation electrode make sure the polarity of the device is observed see connection examples for the control box lfl 1 lgk during ionisation monitoring it is important that the signal is transmitted without wastage the connection cable must not lie adjacent to a multicore cable a soiled sensor electrode bracket or faulty ceramics encourage leakage currents which reduce the flame signal the burner as a counter electrode must be earthed in conformity with the directives if this is not the case an ionisation current cannot flow earthing of the boiler only is often inadequate the ionisation current must be monitored when the burner is set to ensure combustion hygiene i.e when switching from partial load to full load the ionisation current must not fall below the minimum monitoring current required a large drop in the ionisation current indicates either a lack or an excess of air these malfunctions must be corrected using appropriate methods a consistently high ionisation current indicates a stable flame and the correct combustion hygiene en sensor currents automatic controller lfl 1 lgk minimum required 6 µa maximum possible µa recommended instrument range 0 150 µa see technical data for automatic furnace controller lfl 1 lgk 10/2010 art nr 4200 1032 1300a 15

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