Operating instruction
Contents
1. sor switches on as a function of the milk tempera ture e Carry out the electrical connection process as follows e Use cable bushes m Agitator e Make sure that cables cannot chafe contactor Sensor Operating voltage external switch external Li N target temperature push button T1 T2 switch over Intermittent stirring e Connection to external operating controls Operation of the buttons Intermediate stirring and Change target temperature can be transferred to external switches The terminal strip has separate connections for this purpose see connection diagram The operating controls needed in such cases are a button for the Inter mediate stirring function and a selection switch for the function Chan ge target temperature If an external button or selection switch is connected parameter P80 or P81 must be set as appropriate at configuration level Caution do not connect external voltage to the S S or T T terminals Buttons or selection switches used must be designed as potential free make contacts MPR M 26 08 08 Page 5 Housing dimensions and technical data thermostat oooo000000000000 Sensor dimensions and technical data mm E J mms z B Moe MPR M 26 08 08 Operating voltage Relay contact 230 V AC 50 60 Hz 2 make contacts max switching current 16AAC 1 max switching voltage Display 250 V 13 mm LED2. Display 3 digits Display range Range 9 9 99 9 C other Control action 0 1 C 1 0 C two step controller Measurement range look at techn data Sensor Hysteresis 0 1 to 99 9 K free adjustable Standard adjusting 0 7 K Control mode cooling Housing Norm panel housing front panel cut out 90 x 42 mm insertion depht 88 mm Protection housing front IP 64 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 PTC sensor KTY 81 210 Bush material 1 4301 V2A Bush length 40 mm Bush diameter 6 0 mm 0 1 Cable material PVC standard Measurement range KTY 81 210 Cable PVC Cable Silikon Cable lenght Protection type Silicon special model 30 70 C 50 150 C standard 2 metres IP 65 Page 6 Operation V Working level for everyday operation l Programming level for setting the regulatory parameters Configuration level for setting the basic functions Operation overview Target temperature T1 Target temperature T2 MPR M 26 08 08 Hysteresis for T1 Hysteresis for T2 The regulator is operated at three levels Working level for everyday operat
3. or Si temp T2 upw G 7 OOM 2 1 one aed i ol 5 The hysteresis determines the one side symetrical Limit for Hyst 1 f value by which the temperature Hysteresis Hysteresis P30 SET A 0 1 f downwards ea Oav of the medium may deviate from Limit for Hyst 1 gagy mm Y the corresponding target tempe Target Target A i upwards OW 2 rature before the relay contactis 122 temp Limit for Hyst 2 gg am or activated See diagram B bk aV 01 downwards a If the contact in question is for Limit for Hyst 2 g 7 cooling the hysteresis is always Ps a SET A 2 upwards oaov upwards In the case of heating Min action time F Yr contacts it is below the target temperature cooling or Compr K1 OW 0 heating contact is set at configuration level Min pause time py fo f In the symmetrical hysteresis mode the value selected is HED ET A 0 Compr K1 P Oav distributed on both sides of the target temperature Switchin a T toT2 OOV 0 Mode intermitt cs a Parameter P20 Limit for target temp T1 downwards stirring EB s OWM 1 Parameter P21 Limit fortarget temp T1 upwards 1 i es Be Parameter P22 Limit for target temp T2 downwards r e gB m eam o Parameter P23 Limit for target temp T2 upwards E E EE Setting of npu limits for target temperatures at working and Press for 5 seconds simultaneously programming levels Switches back automatically after 30 seconds Range 10 99 C MPR M 26 08 08 Page 10 MPR M 26 08
4. 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 K2 Setting of minimum action time for compressor relay contacts K2 in order to prevent repeated switching on and off Range 0 0 999 seconds Parameter P71 Minimum pause time for compressor K2 Setting of minimum pause time for compressor relay contacts K2 in order to 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 not possible target temperature T1 is active 1 with button standard activate with button T1 T2 2 with external switch external switch open targettemperature T1 is active external switch close targettemperature T2 is active Parameter P81 Function intermittend stirring Setting of funktion start manual intermittend stirring See section Intermediate stirring options during cooling page 12 0 not possible intermittend stirring not possible 1 with button standard activate with button Agitator 2 with external push button 3 permanent stirring ON OFF Parameter P99 temperature scale To switch the display between degrees Fahrenheit and d
5. 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 Fault indication on the display In order to adjust the actual value correction a reference thermometer e g WELBATHM 2000 is needed Proceed as follows Install sensor Measure the milk temperature using the reference thermometer Switch on the thermostat and set parameter C91 in the programming level to 0 Switch back to working level and read the measured temperature on the display Calculate the difference between the reference thermometer temperature and the display reading Store the difference pay attention to plus or minus in the working level under parameter C91 Faults in the regulator are indicated 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 F3 Memory fault Faulty regulator Remove the regulator and send it for repair FFF Measurement range exceeded The maximum measure
6. 101927 by WELBA 26 03 09 Microprocessor regulator type MPR 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 Contents Function MPR M 26 08 08 PUNCIOM i eta a eta ea eoi ira hed ed ee ee E ie aed Page 2 Intended USE ia ia cobb ivtawe ident bew ke eed ieee nae Page 3 MEIC ea ors kirra aa eda a Ete a A a AEE Ma EA E Page 3 lnstallatiom soie neei pinan ena paa E oe Page 4 Housing dimensions and technical data thermostat Page 6 Sensor dimensions and technical data Page 6 MS OD an aeaaea ee Bs gene Mage tena atten eee Ee ste edd S Page 7 Operation overview 2 Page 7 Parameter settings in general 200002 e eee Page 8 Working level operation 20 0 ce eee Page 8 Programming level operation 6 500506 c eee ee eee Page 9 Configuration level operation 0000000 05 Page 10 Intermediate stirring options during cooling Page 12 Setting the actual value correction Page 13 Fault indication on the display 2 20005 Page 13 General measures when using electronic control systems Page 14 The MPR M is a microprocessor regulated milk cooling thermostat with automatic afterstirring It has separate relay contacts f
7. 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 Operation overview for configuration level simultaneously press button Arrow DOWN for approx 3 seconds Switching to configuration level see description e The display then shows the first parameter P5 in the Display Altering Factory confi gura tion level setting setting setting Press Press button button and 4 SET simultanously Meaning of parameters Sensor failure Yt function K1 4 z Ea Sensor failure or Param P5 Function K1 in event of sensor failure function K2 Ta OWM Param P6 Function K2 in event of sensor failure Hysteresis r The switching status of the relay contacts P1G SET A 1 f mode for T1 F oov can be set for the event of a sensor failure Hysteresis EEA Go 0 OFFinth tof fail gB Obv 1 in the event of failure mode for T2 FE H 1 ON in the event of failure Limit for target gy temp T1 pe e A v 0 imi or Parameter P10 Hyst mode for target temperature T1 Limit for target temp T1 upw Fe OOV 10 Parameter P11 Hyst mode for target temperature T2 E l Limit for target eo or with reference to the compressor relay temp T2 downw BET OM 0 js symmetrical it ob Limit for target
8. allel low voltage and sensor lines This distorts measured values and signals and can disrupt the entire regulatory process It is 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 orAC 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 shows 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 in
9. aneously until parameter C7 lit Display Altering Factory setting setting setting Press Press SET and SET or simul button taneously V Target temperat or z for T1 OOV 8 A Target temperat or for T2 SET 5 V 4 Hysteresis for target temp 1 cio or AV 07K o m 4 5 A 5 B Oo O O O O O O O A Hysteresis for or target temp 2 AV 07K A Duration of cea a afterstirring A V 120 sec Duration of op pause A V 20 mins Duration of short ay intermittent c50 2 mins stirring A Duration of long _ me intermittent cSt A V 10 mins stirring AJ Sensor correction cai aa AY v A or Button lock s OHV 0 To switch back to the working level Press for 5 seconds simultaneously Switches back automatically after 30 seconds MPR M 26 08 08 The programming level is for setting the regulatory parameters Access to this level is more complex in order to avoid accidental resetting of the values by the end user Switching to programming level e Press up arrow and down arrow 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 Target temperatur for T1 Parameter C2 Target temperatur for T2 The target temperature is the temperature at which the corre sponding relay contac
10. ce 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 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 sections loose contacts rhythmically changing power stages power converters power breakers high frequency generators Page 14 U O Regulator contact Coil Diode U O Regulator contact AC Coil RC Filter O m l MPR M 26 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 par
11. e compressor and stirrer are automatically switched on again Page 7 Parameter settings in general To adjust a parameter proceed as follows e Select parameter e Hold the SET button down during the adjustment operation e Use the up arrow or down arrow to set the required value NB Holding the arrow down longer changes the value more quickly e Release the SET button To store the changed parameter in the memory first release the arrow and then 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 Working level operation No Function 1 e Sal do c 2 Be ETE AH 1 LED Agitator 3 gs 15 Ba shows if agitator is switched on SET T1 T2 4 F 7 2 LED Compressor 5 shows if compressor relay is switched on 3 LED T1 shows that target temperature T1 is active Operating overview for working level 4 LED T2 shows that target temperature T2 is active present ACTUAL VALUE displayed continuously mel Eae 5 Press button SET Switch from target mum Tl tom T to 12 or Target temperature T1 or T2 displayed temperature T1 to T2 T2 fom T2 to T1 SHORT int
12. egrees Celsius 0 Celsius 1 Fahrenheit Page 11 Intermediate stirring options during cooling MPR M 26 08 08 The microprocessor regulator type MPR 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 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 C50 and C51 Parameter P81 is setto 2 Intermediate stirring SHORT or LONG is switched on via an external switch The same button functions apply as in the case of option a Parameter P81 is set to 3 On request the MPR 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 Page 12 Setting the actual Acorrection can be made to the value
13. erm stirring A 7 Duration corresponds to Adjust target temperature T1 or T2 upwards or until Sho appears sec programmed value C50 downwards by simultaneously pressing button 6 or 7 LONG interm stirrin 3 Duration corresponds to until Lon appears i sec programmed value C51 6 Button Arrow UP Agitator press for appr 1 sec SHORT intermediate stirring Display Altering Factory press for appr 3 sec LONG intermediate stirring sng z w 5 setting See also the section describing the intermediate stirring SET aa options page 12 button taneously or Press button together with button SET hang a ai i BENT 8 adjust the current target temperature upwards Target temperature T2 ma 4e 7 Button Arrow DOWN T1 T2 when LED T28 it ou Switch target temperature from T1 to T2 or from T2 to T1 Changing the targettemperatureis fe nk ee possible only when the button lock Press button together with button SET pes oo level C99 is adjust the current target temperature downwards MPR M 26 03 09 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 Page 8 Programming level operation D A 15 6 V Target temperature T1 Hysteresis for T1 Hysteresis for T2 Target temperature T2 Operating overview for programming level To change to programming level Press for 5 seconds simult
14. ion by the end user The present milk temperature as measured is permanently displayed Further funktions of working level e Switching over the target temperature T1 T2 e Display and changing of the target temperature T1 T2 NB The target temperature can be adjusted here only if the programming level button lock C99 is set to o e Intermittent stirring operated by push button as pro grammed Programming level This is the level at which the regulatory parameters are set Setting is more complex and possible only using specific combinations of buttons so as to prevent accidental chan ges to settings Configuration level This is the level at which the basic functions of the regulator are set As subsequent interventions by the end user after the parameters have been set can result in dangerous chan ges to functions which might not be immediately obvious access to the configuration level is even more complex e The milk is cooled to the selected target temperature T1 or T2 The stirrer runs constantly at this stage e Once the target temperature has been reached the compressor switches off e The stirrer switches off after the programmed afterstir ring time e During refrigeration pauses the stirrer switches on for 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 th
15. le only with the manufacturer s written consent The device is fitted with a resistance temperature sensor The output ports are designed as relay ports The electronic milk cooling thermostat type MPR M fulfils EC requirements for electromagnetic compatibility EMC The safety components meet VDE regulations Safet y The milk cooling thermostat may only be installed by an authorised specialist observing all local safety require ments Only specialists must be allowed to access the environ ment when connected The thermostat contains live components and must not be opened The device must not be used if the housing or the connecti on terminals are damaged No liquids must penetrate the housing The thermostat may be exported to the USA with the per mission of the manufacturer only MPR M 26 08 08 Page 3 Installation a Itis essential not to install the device under the following conditions e severe jolting or vibration e permanent contact with water e relative humidity of more than 90 e sharply fluctuating temperatures condensation e operation in an aggressive atmosphere ammonia or sulphur fumes risk of oxidation e operation in the immediate vicinity of radio transmitters with high levels of spurious radiation b Housing installation The housing is secured by means of two screw attachments on the sides e Make the appropriate front panel cut out for the housing e Push the housing thro
16. ment range of the sensor has been exceeded MPR M 26 08 08 Page 13 General measures when using electronic control systems MPR M 26 08 08 So that even complicated regulatory tasks can be presented to the user in a manner which is clear and simple and ensures high measurement 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 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 As the values given in the table are maximum values operational values should remain well below them However in practi
17. or 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 a short or longer period of intermittent stirring can be set If required a MPR M model is also available with constant stirring where the stirrer is turned on or off by push button Operation of the buttons for intermittent stirring and select target temperature may also be transferred to external switches Separate connections for this purpose are located on the terminal block see connection diagram Page 2 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 electronic milk cooling thermostat type MPR M is used to control the stirrer motors and cooling compressors of milk cooling systems Any other use of the device is permissib
18. t 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 of the intermittent stirring button Parameter C51 Duration of LONG intermittent stirring Duration min of stirring after longer pressing of the intermit tent stirring button Parameter C91 Sensor correction The sensor reading can be provided with a corrector which works cumulatively over the entire measurement range See also the section on sensor installation Page 13 Parameter C99 Button lock Alteration of the target temperatures in the working level can be blocked by setting the button lock 0 lock off 1 lockon Page 9 Configuration level This level is for configuring the regulator s basic functions operation is made even more complex Switching to configuration level e Press button Arrow UP and Arrow DOWN simultaneously for approx 5 seconds The first parameter C1 appears in the display e
19. terference 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 15 MPR M 26 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 voltage 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 16
20. ugh the front panel cut out e Position the screw attachments e Tighten the screws c Fitting the sensor The regulator is pre adjusted to your choice of sensor in the factory When replacing a faulty sensor always use the same type The sensor cable must not be chafed or kinked There must be no strong mechanical pressure on the sensor tube Do not place the sensor and the high voltage cable in the same cable conduit not even within the switchbox Changing the sensor cable length ie mm 3 If it is necessary to shorten or lengthen the sensor cable on installation San EE E or if a sensor other than the one supplied is to be fitted the actual E F value correction parameter must be adjusted accordingly See the section Setting the actual value correction on page 16 Observe the permitted temperature range to which the sensor is suited Sensor cable temperature range C PVC standard 30 to 70 50 to 180 MPR M 26 08 08 Page 4 d Electrical Connection Before connecting ensure that the mains voltage is the same as indicated on the device s type plate A switching contactor for connection of the cooling com pressor is essential Notice technical Data Ph 4 8 Stirring LAL LL Hoe PABANUITANUN OT T T T T As soon as power is connected to the thermostat the stirrer will run for the duration of the program med afterstirring time C10 The cooling compres
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