HM Medical Clinic

 

Mi-262gb_120403.vp

Operating and Installation manual
Oxygen (O2) transmitter with monitoring
Mi-262gb / 2012-04-03 mi-262gb_120403.vp] O -transmitter MG-4000-R2
USE
MG-4000-R2 is designed to measure the O2-con-
The O2-transmitter consists of two parts: the probe tent in flue gases from oil burners, gas burners and the central unit. The probe houses a sensor of and biomass-fired boilers. MG-4000-R2 can, to- zirconium dioxide (ZrO2), heating element, signal gether with a controller, optimize the air/fuel ratio.
amplifier and generator for the ion pump. The cen- The result is the highest possible firing efficiency tral unit houses the electronics for measuring the can be obtained and sustained over time indepen- sensor signal, analogue outputs, relay contacts for dent of changes in the fuel and combustion air.
the alarm outputs, control panel and the powersupply. All functions in the central unit are mana- The probe (MG-4000-R2/S) is installed in the flue ged and monitored by a microprocessor.
gas duct directly after the boiler. The tip of the pro-be is easy to adjust so that it is positioned in the Current measurement values, error indications centre of the flue gas zone. No special gas is re- and set parameters are all presented on the inte- quired for calibration, this is done directly in the grated display.
surrounding air. Installation and use are as easy 8 LEDs provide a quick indication of the operating as using a standard temperature sensor.
TABLE OF CONTENTS
MEASUREMENT PRINCIPLE . . . . . 3 Relationship between O2-content in dry and High O2-content . . . . . . . 15 Low O2-content. . . . . . . . 15 Galvanic isolation . . . . . . . 5 Measurement values. . . . . . . 15 PROBE CALIBRATION . . . . . . . 16 OXYGENE SENSOR CROSS SENSITIVITY . 6 Combustible Gases . . . . . . . 6 Halogen and Sulphur Compounds . . . 6Reducing Atmospheres . . . . . . 6 TROUBLE SHOOTING . . . . . . . 18 No text displayed . . . . . . . 18The Out of range LED flashes . . . . 18 ELECTRICAL CONNECTION . . . . . 7 The Out of range LED is lit. . . . . 18 The High O2-content LED is lit . . . . 18 The Low O2-content LED is lit . . . . 18 MG-4000-R2 shows incorrect O2-content . 18 Connection diagram for Central unit and MG-4000-R2 cannot be calibrated. . . 18 Ground currents . . . . . . . 18 Translation chart MG-4000 // MG-4000-R2 . 9 Error indications . . . . . . . 18 Measurement values. . . . . . . 10 Central unit MG-4000-R2 . . . . . 19 Measuring probe MG-4000-R2/S . . . 19 LIST OF PARAMETERS . . . . . . 20 INITIALIZE OPERATION . . . . . . 11 LCD display . . . . . . . . . 12Keypad . . . . . . . . . . 12Start menu . . . . . . . . . 12The indication of parameters . . . . 12Programming a parameter . . . . . 12 Programme menu . . . . . . . 12Parameter selection . . . . . . 12Programming a value . . . . . . 13Cancelling programming mode . . . 13 The function menu . . . . . . . 13Default settings . . . . . . . . 14 Communication. . . . . . . . 14 Default settings . . . . . . . . 14 MEASUREMENT PRINCIPLE
At higher temperatures (>500 °C) stabilised zirco-
The time of a pump cycle (tp) becomes directly nium dioxide (ZrO2) is a solid electrolyte for oxy- proportional to the surrounding partial pressure gen. This can be used in two ways: from the oxygen (P1). An increase in the surroun-ding oxygen content increases the partial pressure 1. To transport oxygen through a ZrO2-disc (ion (P1) and tp increases. With a decreasing oxygen pump) according to Faraday's first law.
content tp falls. At 0 % O2 tp is approximately 0.5seconds and in fresh air (20.7 % O2) tp is approxi- 2. To measure the ratio of partial pressure from mately 7 seconds.
oxygen on each side of a ZrO2-disc according The sensor is enclosed by a heating element to to Nernst's equation.
maintain the temperature of the ZrO2-discs at 700°C. This makes the sensor insensitive to changes Most modern oxygen meters available on the mar- in the flue gas temperature and the flow rate.
ket use one of the aforementioned principles. Toavoid disadvantages such as relatively large pro-bes, linearization of measurement signals, refe-rence air, etc. both principles can be combined into a dynamic oxygen sensor.
mi-262gb_120403.vp] Principle construction for a dynamic O2-sensor. The sensor consists of two identical ZrO2-discs with platinum electrodes and a platinum ring which Cross-section view of the sensor element. creates a small chamber between the discs. Onedisc is used as a reversible ion pump according to Faraday. The other disc generates a measurement Based on this principle the sensor is very small voltage proportional to the ratio of the oxygen par- and with that the probe can be made small. tial pressure in the chamber (P2) and surroundings q No reference air is required and the Nernst (P1) according to Nernst.
voltage does not need to be linearized. When measuring, the reversible ion pump will al-ternately pressurise and evacuate the chamber.
Reversing takes place at two preset voltage levelsV1 and V2 on the Nernst voltage VN.
Measuring signal from the O2-sensor. Relationship between O
O -content flue gases 2-content in
dry and wet flue gases
MG-4000-R2, which has its probe mounted in the
flue gas duct, measure the O2-content in wet fluegases. Portable O2-measurement instruments ex- tract a gas sample from the duct and measure the content in dry gases.
Fuel - Oil
Following approximate relation between wet anddry flue gas is valid when excess air does not ex-ceed 50%.
O2-content (wet gas) = 0.9 x O2-content (dry gas) Fuel - Bio mass
See graph to the right
Note! If the measuring probe is exposed for redu-
ced atmospherers, e.g. high content of CO (car- bon oxide), the life-span of the probe is reduced.
Therefore, it is of great importance the the O2- control is operating properly.
Relationship between O2-content mi-262gb_120403.vp] in dry and wet flue gases. Central unit
When choosing the position for installation, re- MG-4000-R2 should be located fully visible and member the following: easily accessible. It is important to remember the ambient temperature, max. 45 °C when positioning 1. The central unit must not be subjected to an the unit. The case is fitted with hinges on the ambient temperature higher than 45 °C. Prefe- left-hand side of the cover for easy opening. Make rably the ambient temperature should be sure the cover can be opened fully.
below 30 °C.
Outside dimensions: 2. The signal cable between the probe and the central unit must be a shielded 10 conductor Hole pattern for wall mounting: cable e.g. FKAR-G 10 x 0.5 mm2. The area ofeach conductor should be at least 0.5 mm2.
The correct cable, which is a prerequisite for reliable operations, is enclosed. The cable shi- eld must only be connected in the central unit.
3. The length of the signal cable between the probe and the central unit should be as shortas is practically possible, maximum 10 m.
4. The signal cable between the probe and the central unit must not be routed together withcables used for low or high voltages.
The minimum permitted distance to low
and high voltage cables is 30 cm. Cables
must cross at right angles.
5. Avoid placement where the central unit is sub- jected to vibration.
6. The central unit should be positioned so that the control panel is approximately at eye level.
seperate the probe galvanically from protective When installing the probe it is important to select cor- earth (ground) in the boiler/flue-gas duct which rect placement. It should be easy to remove the pro- could interfere with the measuring. Check that no be from the flue gas duct and easy to connect the electrical connection is between the probe and signal cable between the probe and the central unit.
boiler/duct by measuring the resistance betweenthem both.
1. Fit a 3/4" union on the flue duct after the boiler.
Make sure the union extends outside of the in- sulation to facilitate installation of the probe. It The cable between the probe and the central unit should be installed at a 15° angle to the hori- must NOT be extended. Leave an "eye" on the zontal plane, so that the tip of the probe points cable by the probe so that the probe can be easily slightly downward (see figure 5), alt. top moun- removed from the flue gas duct for calibration and ted (see figure 6). This is to protect the probe duct sweeping.
from condensation water.
The cable between the probe and the central unitand cables to analogue output signals and data 2. Always install the supplied radiation protection communications must be shielded for the best me- (see figure 7) on the probe's insertion tube to asurement result. The shield must only be connec- prevent the sensor's electronics from overhea- ted to the ground rail in the central unit.
ting. Sole use of the radiation protection is notrecommended, the flue gas duct should also be insulated.
The probe must be operational (voltage fed) andalways maintain the operating temperature if it is 3. The probe should be inserted so far that at le- installed in the flue gas duct, irrespective of whet- ast 10 cm of the tube hangs free inside the her the boiler is operational or not. When the pro- duct. This is so the tip of the probe is not coo- be is not in use it should be kept in the surroun- led via the union.
ding air. Wipe the probe dry if it is moist before in- 4. The supplied warning sign concerning precau- tions that should be taken when the boiler is swept must be set up where it is fully visible.
The O2-probe should always be mounted usingthe attached compression fitting which is fitted witha isolation socket made of PTFE (TEFLON â) to Warning against dry-firing!
When "dry-firing" a biomass-fired boiler, the probe must not
be placed in the flue gas duct.
Radiation shield for connection box NOTE! The measuring probe connection box should not be exposed to tempertures above 60 °C and must therefore be protec-
ted against the radiation heat caused by the flue gas duct or the boiler. Good insulation of the flue gas duct and enough space
between the insulation and the probes connection box is important. Always use the attached radiation protection shield.
Union 3/4" inner thread Side mounting of the probe Top mounting of the probe OXYGENE SENSOR CROSS SENSITIVITY
Cross sensitivity with other gases:
The oxygen sensor measures partial oxygen pressure. Gases or chemicals that will have an influence onthe life of the sensor or on the measuring results are: Small amounts of combustible gases will be bur- Long time exposure to reducing atmospheres may ned at the hot Pt-electrode surfaces or Al2O3 filters in time impair the catalytic effect of the Pt-electro- of the sensor.
des and has to be avoided.
In general combustion will be stoichiometric as long as enough oxygen is available, the sensor willmeasure the residual oxygen pressure. Investiga- q Vapours (organic silicone compounds) of RTV (Room Temperature Vulcanised) rub-bers are well known pollutants of zirconia q H2 (Hydrogen) up to 2%; stoichiometric based oxygen sensors. The organic part of the compound will be burned at hot sensor q CO (Carbon Monoxide) up to 2%; stoichio- parts, leaving behind a very fine divided metric combustion SiO2 (Silicone Dioxide/Silica). This SiO2completely blocks the pores and active q CH4 (Methane) up to 2.5%; stoichiometric parts of the electrodes. If RTV rubbers are used we advise to use high quality, well 3 (Ammonia) up to 1500 ppm; stoichio- metric combustion Dust. Fine dust (Carbon parts/soot) might cause clogging of the porous stainless ste- Heavy Metals
el filter and might have an effect on the re- Vapours of metals like Zn (Zinc), Cd (Cadmium), sponse speed of the sensor. Pb (Lead), Bi (Bismuth) will have an effect on the Heavy Shocks or Vibrations might alter catalytic properties of the Pt– electrodes. Exposu- res to these metal vapours has to be avoided.
q Water vapour. Condensing water vapour Halogen and Sulphur Compounds
might cause clogging of filters or internal Small amounts (< 100ppm) of Halogens and/or corrosion of sensor parts. We advise to Sulphur compounds have no effect on the perfor- keep the sensor at operating temperature mance of the oxygen sensor. Higher amounts of or standby temperature when exposed to these gases will in time cause readout problems exhaust gases. Direct exposure to water or, especially in condensing environments, corro- droplets has to be avoided. sion of sensor parts. Investigated gases are: q Halogens, F 2 (Flourine), Cl2 (Chlorine) HCL (Hydrogen Chloride), HF (Hydrogen q SO2 (Sulphur Dioxide)q H2S (Hydrogen Sulphide)q Freonsq CS2 (Carbon Disulfide) Signals to the probe
MG-4000-R2 is fed with 230 VAC, 50 Hz on termi- Positive supply to the +7 Volt DC, 2.5 mA.
nals 1 (neutral) and 3 (phase). The supply should incorporate a circuit-breaker to facilitate servicing.
Feedback signal from ± 50 mVolt, square heating element in wave 1 kHz at 700 °C.
On terminals 5-7 and 8-10, are two potential free Control signal to the ion +6 / -4 Volt, square switching relay contacts. The relay contact func- pump for evacuation.
tion can be programmed on MG-4000-R2, e.g.
Supply to the heating 1.7 A, approx. 4.2 Volt alarm with low O2-content and probe error. The re- DC on probe.
lay contacts are low voltage, 230 VAC.
Measurement zero from the electronics.
Neutral wire to the heating element.
Terminals 11-19 are connected to the probe's ter- Control signal to the ion +6 / -4 Volt, square pump for pressurising.
Measurement signal from the zirconium 0.4 Volt DC.
MG-4000-R2 has two analogue output signals for dioxide sensor.
the current O2-content, a mA-signal (0/4.20 mA) Negative supply to the -5 Volt DC, 2.5 mA.
on terminals 21 (+) and 22 (-) and a Volt-signal probe's electronic.
(0/2.10 V) on terminals 23 (+) and 24 (-).
mi-262gb_120403.vp] NOTE! Common neutral (-). The output signals
are not galvanically isolated from each other.
The probe has low voltage signals, 50 mV. Any ground currents may influence the measurement and it's important that the probe is galvanically iso- MG-4000-R2 has 2 interfaces, RS-232 and lated from ground. This can easy be checked by RS-485. Only one interface at a time can be used.
measuring the resistance between terminal 15 and RS-232 is connected to a modular jack (RJ45) and the ground rail in the central unit.
is designed for Micatrone's Programming adapter, The result of the measuring should be a resistance part no. 60-0972-2.
over 1 MW (Megaohm), break is prefered.
RS-485 is connected to terminals 25 (A) and 26 If the resistance is under 1 MW, the installation of (B) and requires MG-4000-R2 to be equipped with the probe need to be checked. Also check that the Micatrone's Communication module, part no.
output signal don't shorting between terminal 15 and ground. You might need a transmitter with gal- If both RS-232 and RS-485 are connected simulta- vanic separation to the output signal.
neously RS-232 is given priority for communica- tions. Also see the operating description for com- munications on page 11.

Connection diagram for Central unit and Probe
Output signal 2 0/2.10 Volt Ri min 50 kohm O: Produkter MG-4000-R2 CDR Output signal 1 0/4.20 mA RL max 500 ohm

Translation chart MG-4000 // MG-4000-R2
I: MG-4000-R2 CDR Relays
MG-4000-R2 has two potential free switching con-
tacts that can be used to monitor the O2-content or MG-4000-R2 measures the O2-content in flue gas the function of the probe.
using a zirconium dioxide sensor. The measure-ment range of the output signal can be selected between 0.5%, 0.10%, 0.20% or 0.100% O2.
If the measured O2-content is outside of the selec- ted measurement range an orange LED is lit on the control panel.
MG-4000-R2 has visual alarms (red LEDs on the control panel) for specific high and low O The limits are stated in % O 20 Norm.pos.
mi-262gb_120403.vp] The probe must first be calibrated to provide accu- rate measurements. Calibration is performed in fresh air, see page 16. The current barometric pressure can be programmed during calibration on 27 Norm.pos.
MG-4000-R2 to give the best possible accuracy.
The value is stated in mBar.
The function is activated in parameter 14/21 by se- lecting whether the high or low signal is to be mo- Indicates the measurement signal from the probe.
nitored. Select a source (input signal) in parameter Nernst will vary between 0 and 4 Volts during nor- 15/22. If error indication is chosen the function mal measurements.
(parameter 14/21) needs to be programmed to Current & Voltage
Indicates the present current and voltage to the
When monitoring the O2-content a level is pro- probe's heating element.
grammed (parameter 16/23) and a hysteresis (pa- rameter 17/24). The level and the hysteresis are stated in % O2-content. These two parameters are Indicates the present temperature of the probe's not used when monitoring error indication.
zirconium dioxide sensor.
Switching on and off can be delayed by the cho-sen number of seconds in parameters 18/25 and 19/26. In parameter 20/27 the position of the swit- MG-4000-R2 produces two output signals (one for mA ching contact is selected when the monitoring sta- and one for Volt). The output signals state the current te is in normal mode. A yellow LED on the control O2-content for the selected measurement range.
panel comes on when the relay contact is active.
Output signal 1 can be selected between 0.20mA or 4.20 mA and output signal 2 can be selec-ted between 0.10 Volt or 2.10 Volt.
INITIALIZE OPERATION
NOTE! The probe must be operational (voltage
fed) and always maintain operating temperature if A communications module (accessory) can be fit- fitted in the flue gas duct, irrespective of whether ted in MG-4000-R2 to provide data communica- the boiler is operational or shutdown. If the probe tions using RS-485 (2-wire current loop) as the is not operational it should be stored in the sur- rounding air.
There is also an adapter for RS-232 (serial port) NOTE! If the probe is subjected to reducing at-
available as an accessory. The adapter is intended mospheres, e.g. high content of CO (carbon mo- for temporary use, for example, during installation noxide), this will reduce the service life of the pro- and trimming and does NOT require a communi- be. It is important that the O2-control works cor- cations module to be installed. Only one interface (RS-485 or RS-232) can be used at any time.
Check that all connections between the probe and The protocol used is Comli. Parameters and mea- the central unit are correct before MG-4000-R2 is surement values are read with message type 2 connected to the mains supply, 230 VAC.
and new values for parameters are transferred When the power is switched on MG-4000-R2 will with message type 0. The Comli number is the start to heat the probe. This takes approx. 120 se- same as the parameter number. Data communica- conds and during this period the "Out of range" tions can be limited so that only reading is LED will flash.
possible. (parameter 36).
Should an error be discovered, e.g. a faulty con- nection on the signal cable between the probe and the central unit, the "Error" LED lights and the fault is presented in plain text on the display. For a description of how to rectify the error, refer to page If it is the first time that MG-4000-R2 has been started the settings for the selected measurement range and output signals should be checked.
MG-4000-R2 also needs to be calibrated in fresh air to match the central unit with the probe, see The indication of parameters
MG-4000-R2 has a two-row alphanumeric LCD One press of the PGM key when default start display with back light and can show 16 characters menu is showing will activate an automatic scroll on each row. Normally the display indicates pre- and list all parameters for about two seconds. The sent operating values but it is also used to indicate top row indicating the parameter group and bottom measurement values and programmed parameter row the parameter and its value. The listing will end when all parameters has been showed, or ifthe ESC key is pressed.
Keypad
MG-4000-R2 has a keypad with four keys, mar-
Programming a parameter
ked, 6 5, PGM and ESC.
q The arrow keys, 6 5, are used to scroll The program menu includes all parameters and between different parameter groups, para- measuring values that are accessible. All parame- meters and functions and increase or de- ters are divided into different parameter groups crease the value of programmed parame- where each function has its own group.
To activate the program menu, continuously press The PGM key is used for programming and the PGM key until following display is shown. Re- mi-262gb_120403.vp] indicating of set parameters. lease the key.
q By pressing the ESC key ongoing program- ming can be aborted. The ESC key is also used when returning to the start menu. Start menu
The second parameter group is shown on the top The start menu is the entry point for indication and programming of parameters along with special functions such as default programming and calib- By using the arrow keys, 6 5, different groups of If the start menu is not showed on the display, parameters can be selected. If the last group is press repeatedly on the ESC button. The start shown and the arrow key, 6, is pressed, the first menu is by default replaced to indicate operating menu is shown and vice versa.
values. One press of the ESC button shows thestart menu for a short while and returns automati- cally to indicate operating values. Use the arrow keys, 6 5, to scroll between different display alter-natives as follows.
Bottom row
When the desired group is shown, it can be selec- ted by pressing the PGM key once. The first para-meter inside the selected group is shown on the bottom row of the display.
Status Relay 1, Function Status Relay 2, Function With the arrow keys, 6 5, all parameters inside Cancelling programming mode
the group can be selected. If the last parameter in Ongoing programming can be cancelled by pres- the selected group is shown and the arrow key,6, sing the ESC key. The parameter value will stop is pressed, the first parameter is shown and vice flashing and the original value remains the same.
To select another group of parameters when a pa- The function menu
rameters is shown on the bottom row, press the To activate the function menu, press both PGM ESC key. The programming mode is cancelled and ESC key simontaneously and keep the keys when the ESC key is pressed repeatedly until the pressed until the following display is shown. Rele- default start menu is shown.
ase the buttons.
Programming a value
Parameters with a numeric value (integers and de- The first function is shown in the display.
own in the display it can be selected for program-ming by pressing the PGM key once. The first digit will flash to indicate that it can be changed using the arrow keys, 6 5.
Selecting a function: With the arrow keys, 6 5, different functions can be selected, for instance, default programming mi-262gb_120403.vp] and calibration. If the last function is shown and If the digit flashing is "9" and the arrow key, 5, is the arrow key, 6, is pressed, the first function will pressed, the counter will start from "0" and count shown again and vice versa.
forwards (-9 for parameters that accept negative values) without changing any other of the digits in the value. The counter will continue in the opposite Calibration of probe way if the digit is flashing "0" and the arrow key, 6, is pressed. Continue to the next digit by pres- Default settings, Communication sing the PGM key again.
Default settings, Factory When the last digit is set and the PGM key is pres- Calibration analogue inputs *) sed the actual change of the parameter value is af- Calibration analogue outputs *) fected. The entire bottom row in the display willflash to confirm that the programming was suc-cessful.
When the desired function is displayed it can beselected by pressing the PGM key.
Parameters with preset alternatives The functions menu can be aborted by pressing When the selected parameter is shown in the dis- the ESC key.
play it can be selected for programming by pres- *) Calibration of analogue inputs and outputs sing the PGM key once. The entire text will flash to require use of special equipment. All ana- indicate that it can be changed to the preset alter- logue signals are factory calibrated and natives using the arrow keys, 6 5.
should not during normal circumstanceshave to be calibrated again.
The same procedure as with digits will occur if anarrow key, 6 5, is pressed when the last, re- spectively the first, parameter alternative is shown.
By pressing the PGM key, when the desired para-meter alternative is shown, will execute the pro-gramming and change the parameter. The entirebottom row in the display will flash to confirm thatthe programming was successful.
20 Norm.pos.
27 Norm.pos.
0.20mA 4.20mA4.20mA 1200 b2400 b4800 b9600 b Different operating values are shown on displays The following measurement values can be read on in the start menu, see page 12. Use the arrow- the display from the program menu, see page 12.
keys, 6 or 5, to scroll through the different dis-plays with operating values.
Bottom row
100 O2-cont.
Status Relay 1, Function Status Relay 2, Function 90 Cal. Temp.
The LEDs on the control panel indicate the follo-wing: mi-262gb_120403.vp] The following status values can be read on the Flashes green for each new measurement pe- display from the program menu, see page 12.
riod/pump cycle (tp) from the probe, see page 3.
Out of range
Lit orange when the measured O 110 R1 Func.
2-content is outsi- de of the measurement range selected in parame- 112 R2 Func.
Lit orange while calibration of the probe is in pro- 114 Counting.
Lit yellow when the relay contact for terminals 5-7 115 Ionpump.
Lit yellow when the relay contact for terminals 8-10is active.
Key to status texts
R1 Func. and R2 Func.
High O2-content
Lit red when the measured O2-content exceeds
The relay function is shutoff = not used.
the value set in parameter 2.
Waiting for operation = the measurement valuehas passed the limit, but the time for operation has not elapsed.
Lit red when the measured O2-content is below the The measurement value has passed the limit, but value set in parameter 3.
the time for operation has elapsed.
Waiting for release = the measurement value ison the normal side of the limit + connection diffe- Lit red in the event of a probe error. The error is rence, but the time for release has not elapsed.
shown in plain text on the display, see page 18.
The measurement value is on the normal side ofthe limit + connection difference, but the time forrelease has elapsed.
The central unit and probe must be calibrated to- The following text is now shown: gether for MG-4000-R2 to measure the correctO 2-content. If any of the units are replaced a new calibration must be made. Calibration takes about 10 minutes to complete.
The probe is calibrated in fresh air. Remove the Make sure MG-4000-R2 is connected to the mains probe from the flue gas duct and place/hang the supply and the probe. Start calibration at the earli- probe so that at least 10 cm of the tip of the pro-
est 10 minutes after MG-4000-R2 has been star- be is hanging freely in the air.
ted, i.e. that both the mains supply and probe have Remember that the tip is extremely hot. A risk of
been connected. If no error is indicated it is assu- burns exists! Press PGM to continue.
med that the probe has reached its working tem-perature, approx 700 °C.
If calibration is started less than 10 minutes afterthe Calibration is performed from the function menu, MG-4000-R2 the unit will wait until the time remai- see page 16. When the following is displayed: ning has elapsed before continuing with thecalibration.
Calibration ofprobe press PGM to start calibration.
mi-262gb_120403.vp] The following text is now shown: When the counter reaches zero calibration conti- nues with the next step.
The Calibration LED now comes on and the cen- tral unit makes 9 readings from the probe.
You can cancel calibration at any time by pressing The measurement value and temperature from theprobe are shown for each reading.
The function menu is displayed again. No calibra-tion has been performed and the previous calibra- tion value still applies.
Press PGM to continue the calibration. The pro- grammed barometric pressure in mBar is now dis- Five dashes are shown if the measurement value is not approved. If more than 2 measurements failthe probe cannot be calibrated.
Press PGM if the value is OK, otherwise you mustcancel (press ESC) and program the barometric Cancel calibration and check the probe, see page 18.
pressure in question via the program menu, seepage 12.
NOTE! The probe must be operational (voltage
The Calibration LED goes out when calibration is fed) and always maintain operating temperature if complete and the following text is displayed.
fitted in the flue gas duct, irrespective of whetherthe boiler is operational or shutdown. If the probe is not operational it should be stored in thesurrounding air.
NOTE! If the probe is subjected to reducing at-
The 2 numbers are values from the most recent mospheres, e.g. high content of CO (carbon mo- calibration and do not need to be the values noxide), this will reduce the service life of the pro- shown in the example above. Calibration is be. It is important that the O2-control works Press PGM to continue. You will now be asked A design without moving parts means the probe is whether the new calibration should be saved and fairly insensitive to external influences; resulting in used from now on.
a long service life.
However, you should remove the probe from the flue gas duct maybe once after each firing season to check that the tip of the probe is not clogged bysoot or deposits. These deposits can affect the Press PGM to save or ESC to cancel.
probe's time constant, i.e. the reaction time will in-crease with the increase in deposits.
If the tip of the probe is dirty it can be carefully cle- aned using a cloth dampened with, e.g. methyla- ted spirit or petroleum spirits. Make sure that the tip has had time to cool to room temperature.
MG-4000-R2 should be recalibrated for the first Reinsert the probe in the flue gas duct.
time after about 2 months, then roughly once perfiring season.
Fuses
MG-4000-R2 contains 4 fine-wire fuses. These are
Press PGM to complete calibration.
positioned to the right of the transformer and arenumbered FH3, FH2, FH1 and FH4 from the top.
Also see the figure on the terminal diagram.
FH3, 400 mA slow-burn.
Press ESC to close the function menu.
Fuse for the control panel and processor card.
FH2, 400 mA slow-burn.
Double check the calibration, i.e. measure the Fuse for the galvanically isolated supply for data 2-content with the probe in the flue gas duct and read the measurement value on the central unit.
FH1, 400 mA slow-burn.
Estimate whether the measurement value is rea- Fuse for the relay coils and supply to the probe's sonable or make a reference measurement using another O2-transmitter. Change the air or fuel sup-ply and check that the O2-content changes.
FH4, 2 A slow-burn.
Fuse for the probe's heating element.
TROUBLE SHOOTING
No text displayed
Check that MG-4000-R2 is voltage fed, 230 VAC Should MG-4000-R2 discover an internal fault, for on terminals 1 and 3.
example on the probe, this is indicated by a redLED on the control panel and text on the display.
Check the 3 fuses to the right of the uppermosttransformer on the left-hand side of the PCB. They In the event of an error the O2-content will indicate should be 400 mAT, 5x20 mm glass-tube fuses.
0.0 % O2 and the output signals will drop to a mini-mum. This is to guarantee an excess of air for The Out of range LED flashes
MG-4000-R2 has just been started and the probe Relay 1 and Relay 2 can be programmed to send is warming up.
out a signal when an error occurs, see page 10.
The Out of range LED is lit
The error texts that can appear on the display are MG-4000-R2 is measuring O presented below.
2-content that is outsi- de of the selected measurement range. This is Nernst, Signal too high/low
normal when the boiler has stopped and the fluegas duct contains fresh air. If this occurs when the The measurement signal from the probe has been boiler is operational a larger measurement range outside of its working range 0.4 Volt for some should be selected in parameter 1.
time. Restart MG-4000-R2 to try to reset the error.
Check the connections between the central unit The High O
and the probe. Try another probe.
2-content LED is lit
MG-4000-R2 is measuring O2-content in excess of Current, Signal too high.
the value in parameter 2.
Too much current, > 2.5 A, is fed from the central unit to the heating element in the probe. Try anot- 2-content LED is lit
MG-4000-R2 is measuring O2-content below thevalue in parameter 3.
Current, Signal too low.
Too little current, < 0.5 A, is fed from the central MG-4000-R2 shows incorrect O
unit to the heating element in the probe. Check Calibrate, see page 16.
fuse FH4 in the central unit. Check the connec- tions between the central unit and the probe. Try MG-4000-R2 cannot be calibrated
another probe.
Check the connections between the central unitand the probe.
Voltage, Signal too high.
Read the Counter measurement value via the pro- Too high voltage, > 8.0 Volt, is fed from the central gram menu. The value should be between 30000 unit to the heating element in the probe. Check the and 50000 when the probe is warm and is in fresh connections between the central unit and the pro- air at normal barometric pressure.
be. Try another probe.
Voltage, Signal too low.
Too low voltage, < 2.0 Volt, is being fed from the The probe has low voltage signals, 50 mV. Any central unit to the heating element in the probe.
ground currents may influence the measurement Check fuse FH in the central unit. Check the con- and it's important that the probe is galvanically nections between the central unit and the probe.
isolated from ground. This can easy be checked Try another probe.
by measuring the resistance between terminal 15and the ground rail in the central unit.
Temperature, Signal too high/low
The result of the measuring should be a resistance The probe does not maintain the right working over 1 MW (Megaohm), break is prefered.
temperature. Restart MG-4000-R2 to try to resetthe error. Check the connections between the cen- If the resistance is under 1 MW, the installation of tral unit and the probe. Try another probe.
the probe need to be checked. Also check that theoutput signal don't shorting between terminal 15 No measurement period, Defective probe
and ground. You might need a transmitter with gal- Restart MG-4000-R2 to try to reset the error.
vanic separation to the output signal.
Check the connections between the central unitand the probe. Try another probe.
TECHNICAL DATA
Central unit MG-4000-R2
Measuring probe MG-4000-R2/S
230 VAC, 50/60 Hz Temperature range for Power consumption: Ambient temperature: Flue gas velocity: recommended < 30 °C Ambient temperature for Max. temperature at the 12 holes ø 20 mm compression fitting: Degree of protection: 1.5 mm2/term.
Dimensions: h x w x d 360 x 300 x 140 mm Cable to central unit: FKAR-G 10x0,5 mm2 Degree of protection: Material insertion tube: Material connections max 5 % of rangemax 0,2 %-units of theO2-content mi-262gb_120403.vp] Relay outputs
Max. load:
VoltSignal range: RS-485 or. RS-232 Dimensions measuring probe MG-4000-R2/S LIST OF PARAMETERS
90 Cal. Temp.
110 R1 Func.
20 Norm.pos.
112 R2 Func.
114 Counting.
115 Ionpump.
27 Norm.pos.
1200 b2400 b4800 b9600 b AB MICATRONE
Telephone: +46 8-470 25 00
+46 8-470 25 99
SE-171 48 SOLNA

Source: http://www.micatrone.se/download/docs/mima_gb/mi-262gb_120403.pdf