MRF-M Milk-cooling regulator Installation and operating instructions
Contents
1. automatic afterstirring It has separate relay contacts for the compressor contactor and the stirrer The measured milk temperature is shown constantly on the display Two freely adjustable target temperatures may be selected by push buttons Should the milk temperature exceed the chosen target tempe rature T1 or T2 by the hysteresis value the compressor and stirrer are automatically switched on Once the target temperature is reached the compressor contactor switches off The stirrer continues for the pro grammed period During refrigeration pauses the stirrer automatically switches on again according to the programmed intervals to ensure an even temperature throughout the milk Independently of this short or long intermediate stirring can be selec ted by pressing a button Software can also be used to programme the MRF M for permanent stirring i e the agitator is switched on and off by pressing a button Cooling mode Press the button cooling the compressor and agitator operate automati cally In between cooling periods agitator and compressor LEDs off intermediate stirring can be activated If the start delay is activated parameter c80 gt 0 the start of cooling mode is delayed Pressing the button twice causes cooling to start immediately Stirring mode If cooling mode is active temperature ist shown on display e Short intermediate stirring Briefly press the Agitator button sho appears in the dis2. failure or Parameter P6 Function K2 in event of sensor failure function K2 a 9 Oayv 1 TN The switching status of the relay contacts can be K2 Ki Hysteresis am d set for the event of a sensor failure Em e Osv 1 made form A 0 OFF in the event of failure v Y Hysteresis E 1 ONin the eventoffailure mode for T2 Oav LOIS Limit for target Be Parameter P10 Hyst mode for target temperature T1 Pe AV 1 m downw zao Parameter P11 Hyst mode for target temperature T2 imit for target or ee m ek Qn v o with reference to the compressor relay c A 0 symmetrical one side symetrical Limit for target or H temp T2 did Oav 1 1 one sided Hysteresis Hysteresis Limit for target a The hysteresis determines the Jaroet v temp T2upw GEE OQ v 10 value by which the temperature tens EU imi A of the medium may deviate from Limit for Hyst 1 or donans amp Q v u the corresponding target tempe Ee A rature before the relay contact is Limit for Hyst 1 or quies n Q v 15 activated See diagram imi A If the contact in question is for cooling the hysteresis is Limit for Hyst 2 rf MEE SEE 9 OAV 0 aways upwards In the case of heating contacts it is below e A the target temperature cooling or heating contact is set at Limit for Hyst 2 er arde G Q v 15 configuration level in action ti A In the trical hyst i de th lected i Min action time or n the symmetrical hysteresis mode the value s
3. may be exposed Degree of Environment Test voltage Test voltage severity class Power supply Signal control line 1 well protected 0 5 kV 0 25 kV environment 2 protected 1 0 kV 0 5 kV environment 3 typical industrial 2 0 kV 1 0 kV environment 4 Industrial environ 4 0 kV 2 0 kV ment with very high interference level Asthe values given in the table are maximum values operational values should remain well below them However in practice this is possible only with difficulty as even a normal contactor without interference suppres sion produces interference pulses of up to 3 0 kV For this reason we recommend that the following principles be taken into account during installation a Try to eliminate all sources of interference by carrying out interference suppression and minimising the interference level Radio interference suppression is required under VDE 0875 and confirmed by VDE 0874 In principle interference must be eliminated at source The nearer the interference suppresser is to the source of interference the greater its effect Interference spreads through wires or by electromagnetic radiation It is usually the former which interferes most seriously with regulation systems Possible interference sources to name but a few include e bouncing contacts when switching loads e switching off inductive loads contactors motors solenoid valves etc unsatisfactory routing of wires too small cross sectio
4. 100994 by WELBA 28 08 08 Milk cooling regulator MRF M Installation and operating instructions for plant engineering companies WELBA GmbH Phone 49 0 2638 9320 0 Electronic Control Engineering Fax 49 0 2638 9320 20 Gewerbepark Siebenmorgen 6 E mail info welba de D 53547 Breitscheid Net www welba de Content MRF M 28 08 08 giri u siaii e aera TC Page 3 Intended USS nues Wis vie de oen Ss eee e Be Rae ed Page 4 srl ete adie fees Page 4 Installation Cm Page 5 Electrical connection uuu asper Roe Se x o o Rr ues Page 6 Technical data regulator i caesa kb Rs Page 7 Sensor dimensions and technical data Page 7 o oana vende ae MEI Shee kee vem Pale whee des Page 8 Operation overview zs rae ex dos E be ewe node ede Page 8 Parameter settings in general 0000 0000s Page 9 Working level operation lsllseselesseleesss Page 10 Programming level operation 0 600002 0 ees Page 11 Configuration level operation 0 00000005 Page 12 Intermediate stirring options during cooling Page 14 Function permanent stirring 2 2 06 cile Page 14 Setting the actual value correction 04 Page 15 Fault indication on the display llle Page 15 General measures when using electronic control systems Page 16 Page 2 Function MRF M 28 08 08 The MRF M is a microprocessor regulated milk cooling regulator with
5. 28 08 08 Page 8 Parameter settings in To adjust a parameter proceed as follows general e Select parameter e Holdthe button 1 down during the adjustment operation e Use the up arrow 4 or down arrow 3 to set the required value Note Holding the arrow down longer changes the value more quickly e Release the button 1 To store the changed parameter in the memory first release the arrow andthen the SET button Switching back to working level possible from any parameter e Press up arrow and down arrow simultaneously for approx 5 seconds The current actual value appears in the display If at programming or configuration level no buttons are pressed for approx 1 minute the regulator switches back to working level automati cally MRF M 28 08 08 Page 9 Working level operation Operating overview for working level present ACTUAL VALUE displayed continuously The LED changes Ti A m Bu jm aw ji T2 from T1 to T2 or emperature 0 f from T2 to T1 SHORT interm stirring Co 1 Duration corresponds to until Sho appears sec programmed value c50 1 irri Duration corresponds to LONG interm stirring 69 until Lon appears AV sece programmed value c51 Display Altering Factory setting selting setting Press Press button 1 button and or if simultaneously or Target temperature T1 AV 4 when LED T1 lit Target temperature T2 i 4 when LED T2 lit Ay Changing the targ
6. 50 and c51 Parameter P81 is set to 2 On request the MRF M can be set for continuous stirring i e the agitator can be switched on and off by pressing a button When the agitator is switched on or off the display briefly indicates ON or OFF In OFF mode continuous stirring can be selected by pressing the agitator button and switched off again by pressing the 1 button During continuous stirring the agitator LED lights up and a rotating bar is shown in the display Page 14 Setting the actual A correction can be made to the value as measured by the sensor which value correction applies cumulatively over the entire measuring range This is necessary when the length of the sensor cable is changed or a faulty sensor is replaced giving rise to an incorrect reading In order to adjust the actual value correction a reference thermometer e g WELBATHM 2000 is needed Proceed as follows e Install sensor e Measure the milk temperature using the reference thermometer e Switch on the regulator and set parameter c91 in the programming level to 0 e Switch back to working level and read the measured temperature onthe display e Calculate the difference between the reference thermometer temperature and the display reading e Store the difference pay attention to plus or minus in the working level under parameter c91 Fault indication on the display Faults in the regulator are indicat
7. arget temperatures is only possible for everyday operation when in programming level the parameter button lock c99 is setto 0 i Programming level Programming This is the level at which the regulatory parameters are set level Setting is more complex and possible only using specific combinations of buttons so as to prevent accidental chan for setting the regulatory parameters ges to settings l Configuration level This is the level at which the basic functions of the regulator Configuration are set level As subsequent interventions by the end user after the para for setting the basic functions meters have been set can result in dangerous changes to functions which might not be immediately obvious access to the configuration level is even more complex Operation overview e The milk is cooled to the selected target temperature T1 or T2 The stirrer runs constantly atthis stage e Once the target temperature has been reached the Target compressor switches off temperature T1 bd e The stirrer switches off after the programmed afterstir EH ring time Target e During refrigeration pauses the stirrer switches on for Hyst inde temperature T2 um the duration of the afterstirring time to ensure an even temperature throughout the milk e Should the milk temperature exceed the selected target temperature T1 or T2 by the hysteresis value the compressor and stirrer are automatically switched on again MRF M
8. ed by a flashing display as follows LED Display Fault F1 Sensor short circuit The sensor or sensor cable is faulty and must be replaced or repaired Parameter c91 Actual value correction must then be adjusted at programming level F2 Broken sensor The sensor or sensor cable is faulty and must be replaced or repaired Parameter c91 Actual value correction must then be adjusted at programming level FFF Measurement range exceeded The maximum measurement range of the sensor has been exceeded MRF M 28 08 08 Page 15 General measures when So that even complicated regulatory tasks can be presented to the user using electronic control in a manner which is clear and simple and ensures high measurement systems accuracy today s electronic control systems make increasing use of microprocessors However the benefits of these systems are countered by the disadvantage that increased measurement accuracy is accom panied by sensitivity to interference In order to minimise the effect which interference may have on the regulator the user also must take account of a number of points when installing a new regulator Assistance here is provided by standard DIN VDE 0843 on the electro magnetic compatibility EMC of measurement control and regulatory devices in industrial process technology The following table shows for example the maximum interference levels to which according to the standard an appliance
9. elected is Compr K1 Q v distributed on both sides of the target temperature A Min pause time d NE K1 BE Oav o Parameter P20 Limit for target temp T1 downwards Suirehih A 7 Parameter P21 Limit for target temp T1 upwards Ti to T2 1 ME o Oav 1 Parameter P22 Limitfortargettemp T2 downwards Parameter P23 Limitfortarget temp T2 upwards Q v 1 Setting of input limits for target temperatures at working and programming levels A Mode intermitt Stirring Pai To switch back to the working level o Press for 5 seconds simultaneously Range 10 99 C Switches back automatically after 30 seconds MRF M 28 08 08 Page 12 MRF M 28 08 08 Parameter P30 Limit for hysteresis T1 downwards Parameter P31 Limit for hysteresis T1 upwards Parameter P32 Limit for hysteresis T2 downwards Parameter P33 Limit for hysteresis T2 upwards Setting of input limits for hysteresis at programming level Range 0 99K Parameter P70 Minimum action time for compressor K1 Setting of minimum action time for compressor relay contacts K1 in orderto prevent repeated switching on and off Range 0 0 999 seconds Parameter P71 Minimum pause time for compressor K1 Setting of minimum pause time for compressor relay contacts K1 in orderto prevent repeated switching on and off Range 0 0 999 seconds Parameter P80 Switch from target temperatur T1 to T2 Setting of funktion switching target temperature 0 2 not pos
10. et temperature is possible only when the button lock in the programming level c99 is set to 0 MRF M 28 08 08 The working level is for day to day milk cooling operation When the regulator is switched on the display continuously shows the current milk temperature Button Function Button 1 only in OFF mode start cooling Button 1 only in cooling mode Target temperature T1 or T2 displayed Adjust target temperature T1 or T2 upwards or downwards by simultaneously pressing button 1 with button 2 or 4 in cooling mode Button 2 OFF regulator in STAND BY mode Button 3 in cooling mode switch target temperature from T1 to T2 or from T2 to T1 if T2 is active Press T1 T2 button together with button 1 to adjust the current target temperature downwards LED Button 4 in cooling mode press for appr 1 sec SHORT intermediate stirring press for appr 3 sec LONG intermediate stirring See also the section describing the intermediate stirring options page 14 Button 4 in OFF mode continuous stirring Press the agitator button together with button 1 to adjust the current target temperature upwards Function LED 5 Agitator in cooling mode if permanent lid shows if agitator is switched on if flashing shows that mode continuous stirring is active LED 6 Compressor if permanent lid shows if compressor relay is switched on
11. ge switches is also recommended The suggestions made represent only a few of the possible ways of protecting a microprocessor controlled regulator system from interfe rence The suggested measures have the advantage that they will increase the lifetime of the devices as lower induction voltages redu ced spark formation will also reduce contact burn Page 18
12. gressive atmospheres ammonia or sulphur fumes Risk of oxidation e operation in the immediate vicinity of radio transmitters with increased levels of spurious radiation Installation of housing Forfixing the case please follow the instruction e While putting in the seal 1 please note that the seal does not turn around and that it is carefully fixed in the seal groove e Put the regulator from the front through the switchboard opening 87 x 56 mm e Push the holding device frame 2 from the back above the regulator and fix it with the attached screws 3 Switchboard opening e Carry out the electr wiring and sensor connec 87 x 56 mm tion as mentioned in the following description e Spritzschutzabdeckung 4 montieren optional MERE MEM RE LIII Sensores Lih nr niacoaInaeonenaran ernaeoeniunuisaiuliadueccanmniolinino same cable conduit not even within the switchbox Changing the sensor cable length If itis necessary to shorten or lengthen the sensor cable on installation or if a sensor other than the one supplied is to be fitted the actual value correction parameter must be adjusted accordingly See the section Setting the actual value correction on page 15 MRF M 28 08 08 Page 5 Electrical connection Before connecting ensure that the mains voltage is the same as indicated on the device s type plate Incorrect electrical connection can cause damage to the regulator and to the equipment The main
13. has been done as this might result in damage to the plant and the item to be cooled or heated The device is fitted with a resistance temperature sensor The output ports are designed as potential free relay ports atmospheres The microprocessor controlled regulator type MRF M fulfils the EC requirements for electromagnetic compatibility EMC and the Low Voltage Directive LVD The safety components meetthe VDE regulations CC The device must not be installed in potentially explosive Safet y These operating instructions contain important technical and safety information Please read them carefully before installation and before working on or with the regulator The microprocessor regulator must be installed by an authorised specialist observing local safety regulations Access to the environment when connected must be restricted to specialised personnel The microprocessor regulator contains live components and must not be opened up It must not be used if the housing or connection terminals are damaged No fluids must penetrate the housing The microprocessor regulator may not be exported to the USA without the manufacturer s express permission MRF M 28 08 08 Page 4 Installation It is essential not to install the device under the following conditions e severe jolting or vibration permanent contact with water relative humidity of more than 9096 sharply fluctuating temperatures condensation ag
14. he sensor reading can be provided with a corrector which works cumulatively over the entire measurement range See also the section on sensor installation page 14 Parameter c98 Installed software version Parameter c99 Button lock Alteration of the target temperatures in the working level can be blocked by setting the button lock 0 z lock off 1 lockon Page 11 Configuration level This level is for configuring the regulator s basic functions operation To prevent interference by the end user access is made even more complex Switching to configuration level e Press button Arrow UP 4 and Arrow DOWN 3 simultaneously for approx 5 seconds The first parameter c1 appears in the display e Press button Arrow UP repeatedly until the last parameter c99 at working level is reached e Press button Arrow UP again and hold down until Pb appears in the display e When Pb appears hold down button Arrow UP and simultaneously press button Arrow DOWN for z z approx 3 seconds t f f t level SperationoveriiewTorcontiguration deve e The display then shows the first parameter r5 in the Switching to configuration level see description configuration level Display Altering Factory setting setting setting Press Press button 1 button and or A Meaning of parameters 1 simultaneously Sensor failure or function K1 e Oav i Parameter P5 Function K1 in event of sensor failure Sensor
15. if flashing start delay is active LED 7 T1 zeigt an shows that target temperature setting T1 is active LED 8 T2 zeigt an shows that target temperature setting T2 is active Page 10 Programming level operation Target temperature T 1 Target temperature T2 Operating overview for programming level To change to programming level Press for 5 seconds Display setting Hysteresis a 2i Hysteresis or T2 simultaneously until parameter C1 lit Altering setting Factory setting Press Press button 1 button and or ji simultaneously Target temperat Av for Ti ald Target temperat d 25 for T2 Oav 2 Hysteresis for xd target temp 1 cig amp Q v 08k A Hysteresis for or targettemp 2 Gall OAV osk A Duration of or afterstirring coo 8 Q v 120sek Duration FEE 9 O v soni pause X Duration of short or intermittent o A V 2min stirring uration of long or i intermittent col Q v 30min stirring A Delayed Start Q v Onin Sensor E g correction AY or Software version Oav A or Button lock Oav 0 To switch back to the working level MRF M 28 08 08 Press for 5 seconds simultaneously Switches back automatically after 30 seconds The programming level is for setting the regulatory parameters Access to this level is more complex in order to avoid accidental resetting ofthe values by the end u
16. ns loose contacts rhythmically changing power stages power converters power breakers high frequency generators MRF M 28 08 08 Page 16 Regulator contact Coil Diode AC o Regulator contact Coil RC Filter HK l MRF M 28 08 08 If specific interference sources cannot be avoided they should at least be kept ata distance from the regulator system Capacitive and inductive couplings can cause crosstalk between high voltage lines and parallel low voltage and sensor lines This distorts measured values and signals and can disrupt the entire regulatory process Itis therefore recommended that all sensors and signal lines be placed separately from the control and mains voltage lines If possible a separate mains line should be provided to feed the regula tor system This helps reduce any interference penetrating the regulator via the mains supply line Voltage surges resulting from switching substantial loads will also then be less of a problem In the case of contactors solenoid valves and other inductive consu mers the induction voltage occurring during switching has to be redu ced by appropriate protection methods The choice of methods depends on whether the consumer runs on DC or AC voltage e DC voltage In the case of d c voltage systems the induction voltage occurring can for example be limited by using self induction diodes varistors or suppresser diodes The diagram on the left show
17. play and the agitator starts to operate e Long intermediate stirring Press and hold down the Agitator button for 5 seconds lon appears in the display and the agitator starts to operate e Continuous stirring only if set at parameter level Press the Agitator button On appears in the display The agitator operates continuously until the Agitator button is pressed again If OFF mode is active OFF ist shown on display e Continuous stirring while cooling is switched off Press the Agitator button Actual temperature is shown in the display and the agitator LED is flashing Off mode The regulator can be switched off using the OFF button OFF appe ars in the display Both the output relays for the agitator and compressor are deactivated CAUTION Theregulatoris live even when switched off T1 T2 Switch between target temperatures when cooling mode is active only Page 3 Intended use These operating instructions contain important technical and safety information Please read carefully before installation and before any work on or with the regulator The microprocessor controlled regulator type MRF M is used to control heating and cooling systerns alarm devices fans etc Any other use of the device is permitted only with prior written permission from the manufacturer The microprocessor regulator is ready for use once the parameters have been set It should not be used bef re this
18. s one possibility using a self induction diode e AC voltage In the case of a c voltage interference suppression as described above is not possible Instead an RC combination must be used An RC filter must be connected as directly as possible to the inductance in order to ensure a short line In addition the component ratings of the RC combination must be geared to the inductance Too low ratings lead to excessive voltage and too high ratings cause significant losses in the interference suppresser component Another point to note here is that only capacitors which meet VDE 0656 may be used They must be suited to the mains voltage and designed for very high switching voltages The diagram on the left shows inductance interference suppression using an RC filter An RC filter should not be fitted directly to the regulator s switching contact as shown on the left as an idle current will flow through the RC combination even when the switching contact is open This current may be enough to mean that a downstream contactor is not de energised and aclosed protective contact does not reopen Page 17 MRF M 28 08 08 Semiconductor switches such as thyristors or triacs also produce interference voltages They occur as a result of non linear characteris tics and finite ignition voltages These components must be protected against excessive voltages for which mainly varistors RC combina tions or choke coils are used The use of zero volta
19. s voltage should not be switched on until all components including the sensor are connected When connecting appliances or loading the relay con tacts with currents of 210A AC1 it is essential to fit con tactors Downstream contactors must be fitted with an RC protecti on circuit see also page 17 You will find the correct circuit diagram for your regulator on the back ofthe housing above the connection terminals Sensor As soon as power is connected to the regulator the stirrer will run for the duration of the programmed afterstirring time c20 Compressor The cooling compressor switches on as a function of the milk tempe rature e Electrical connections must be as shown in the diagram below e Use cable bushes e Make sure that cables cannot chafe Operating voltage MRF M 28 08 08 Page 6 Housing dimensions and technical data regulator Sensor dimensions and technical data li 3 mammt 7 31 FHI 33 gt 2 33 MRF M 28 08 08 Operating voltage Relay contacts max switching current max switching voltage Display 230 V AC 50 60 Hz depending on model 2 make contacts 16AAC 1 each 250 V 13 mm LED Display 3 digits Display range Range 9 9 99 9 C 0 1 C other 1 0 C Control action two
20. ser Switching to programming level e Press up arrow 4 and down arrow 3 simultaneously for approx 5 seconds The first parameter c1 appears in the display e Press up arrow or down arrow until you reach the parameter you want to adjust Meaning of parameters Parameter c1 Targettemperature for T1 Parameter c2 Targettemperature for T2 The target temperature is the temperature at which the corre sponding relay contact is to be activated Parameter c10 Hysteresis for target temp 1 Parameter c11 Hysteresis for target temp 2 The hysteresis determines how much the milk temperature may deviate from the target temperature before the cooling com pressor is switched on Parameter c20 Duration of afterstirring Duration sec for which the stirrer runs after the compressor has switched off Parameter c21 Duration of pause Duration min until the stirrer is switched back on after being turned off Parameter c50 Duration of SHORT intermittent stirring Duration min of stirring after short pressing ofthe intermittent stirring button Parameter c51 Duration of LONG intermittent stirring Duration min of stirring after longer pressing of the intermit tent stirring button Parameter c80 Delayed start After the cooling mode button is pressed cooling does not start until the period of timeset using this facility has elapsed During this period the LED stirrer blinks Parameter c91 Sensor correction T
21. sible target temperature T 1 is active 1 7 with button standard activate with button T1 T2 Parameter P81 Function intermittend stirring Setting of funktion start manual intermittend stirring See section Intermediate stirring options during cooling page 14 0 2 not possible intermittend stirring not possible 1 2 with button standard activate with button Agitator 2 permanent stirring ON OFF Page 13 Intermediate stirring options during cooling co Continuous stirring in OFF mode MRF M 28 08 08 The microprocessor regulator type MRF M has a function allowing the agitator to be switched on manually This can be done is different ways Regardless of the option chosen the corresponding LED always indicates when the agitator is operating The function is set at configuration level using parameter P81 Parameter P8 1 is set to 0 Intermediate stirring is not possible Parameter P81 is setto 1 Intermediate stirring SHORT or LONG can be switched on via the regulator s foil keyboard In this case e Intermediate stirring SHORT Press agitator button for approx 1 sec until Sho appears in the display Release the button immediately otherwise Intermediate stirring LONG will be activated e Intermediate stirring LONG Press agitator button for approx 3 secs until Lon appears in the display The duration of SHORT or LONG stirring is fixed at settings level using parameters c
22. step controller Measurement range 10 to 80 C Hysteresis 0 1 to 99 9 K free adjustable Standard adjusting 0 8 K Control mode Protection housing front cooling IP 65 Connection Environment specifications storage temperatur operation temperatur max humidity Screw terminals 20 to 70 C 0 to 50 C 75 no dew Technical facts with reservation Sensor element KTY sensor Bush material 1 4301 V2A Bush length 40 mm Bush diameter 6 0 mm 0 1 Cable material PVC Measurement range 10 70 C Cable lenght Standard 2 metres Protection type IP 65 Sensors other than our standard type are available on request different bush from or cable length Some of the options are shown here Page 7 Operation The regulator is operated at three levels Working level for everyday operation by the end user When cooling mode is active the milk temperature a s currently measured is permanently displayed The working level also contains the functions e start cooling mode e Intermitted stirring during cooling mode duration depen ding on pre setting See section Intermediate stirring options during cooling on Page 14 e Start permanent stirring l e Switch of e Switch over target temperatures T1 T2 when activ Working e Display and change of target temperatures T1 T2 level Note The changing of t
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