Merloni Elettrodomestici Technical Manual FULL NO FROST COMBINED UNIT (2003) All parts quoted in this document are the property of Merloni Elettrodomestici S.p.A. All rights reserved. This document and the information it contains are supplied without liability arising from possible errors or omissions.
Merloni Elettrodomestici Index PRODUCT RANGE 3 1.1 Full No Frost Combined Models 1.2 Control panels / User interface LEGENDS 3 4 5 LEGEND INDESIT NEW STYLING 2003 REFRIGERATORS / COMBINED MODELS 7 2 Double door Combined units FUNCTIONING LOGICS 7 8 9 3 CHARACTERISTICS OF THE APPLIANCE 11 4 No Frost with display No Frost Standard ANALYZING THE LOADS 11 35 12 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.
Merloni Elettrodomestici 1 PRODUCT RANGE 1.
Merloni Elettrodomestici 1.
Merloni Elettrodomestici LEGENDS * Class A/B Double Door 1 2 3 D 4 - Litres Single mechanical compressor Double mechanical compressor Single electronic compressor FIP Display Display like evolution 1 2 3 4 5 6 7 8 9 - White Stainless steel Bright silver Yellow Blue Teak Pearl Brown Pearl White Grey Blue NF No Frost V Air C Chiller * If the class is lower than B, the class is not written in the description (MT 4511 NF TK).
Merloni Elettrodomestici • 3rd NUMBER 1 2 3 4 D • 1 Compressor 2 Compressors 1 Compressor + Solenoid valve 1 Compressor + Solenoid valve + Display + Air Display 4th NUMBER 1 2 3 4 5 6 8 9 • White Stainless steel Bright silver Yellow Blue Teak White (French market only) S/steel (French market only) Other letters indicate performances C V E BS NF Chiller Air Ever Fresh (Vacuum Kit) Bacteria stop (Cell with Antimicrobic film) Full No-Frost EXAMPLE: 330 litres AIR MTA 332 V Double door MT A 33
Merloni Elettrodomestici LEGEND INDESIT NEW STYLING 2003 REFRIGERATORS / COMBINED MODELS Double door T Top freezer A / A+ Efficiency class A E Evolution 2 = 290 litres 1st number 3 = 340 litres 4 = 400 litres T = Teak B = Blue Colour Y = Yellow S = Silver X = S/steel Refrigerant gas I = Isobutane (FR) = France Intended markets (SP) = Spain Etc.
Merloni Elettrodomestici Combined units B Bottom freezer A / A+ Efficiency class A E Evolution 1 = 1 compressor 1st number 3 = 1 compressor + EV or 1 compressor + electronic control 2 = 330 litres 2nd number (3rd not compulsory) 3 = 380 litres 39 = 390 litres 4 = 400 litres Combined B 1 compressor E Evolution 1 380 litres 3 P S (FR) Playzone Silver France Exception FNF SP: Play Zone and Chiller are implied (therefore in the description, “PC” are not given).
Merloni Elettrodomestici 2 FUNCTIONING LOGICS The refrigeration system consists of a compressor, a condenser on the rear wall of the appliance and an evaporator coil located in the freezer compartment. The cold produced by the evaporator coil reaches the freezer compartment by means of the freezer fan, and reaches the refrigerator compartment by the delivery ducting and the refrigerator fan and is distributed in the various shelves through the multiflow.
Merloni Elettrodomestici Set temperature Freezer switching on temperature Freezer switching off temperature Set temperature Refrigerator switching on temperature Refrigerator switching off temperature -18 °C -18 °C -22 °C 8 14 °C 12 °C -18 °C -19 °C -22 °C 7 10 °C 8 °C -19 °C -22 °C -23 °C 6 8 °C 7.5 °C -20 °C -22 °C -25 °C 5 7 °C 6 °C -21 °C -23 °C -26 °C 4 5 °C 4 °C -22 °C -24 °C -27 °C 3 4 °C 3.
Merloni Elettrodomestici 3 CHARACTERISTICS OF THE APPLIANCE No Frost with display Standard No Frost On FR door: 6 Keys: (1) ON/OFF for switching the appliance on and off; (2) ECO for activation/deactivation of the ECO function; (3) RESET ALARM for resetting alarm conditions; (4) MODE, (5) ADJUST SELECT + and (6) ADJUST SELECT - for shifting on the display 1 Display: for adjusting the freezer (FZ) and fridge (FR), setting the various functions and signalling for the user 1 Buzzer: on electronic board hou
Merloni Elettrodomestici 4 ANALYZING THE LOADS 1. Compressor The compressor, managed by the electronic board, is normally on when at least one of the two compartments demands refrigeration, i.e., when the temperatures of the freezer and/or refrigerator air sensor are such as to activate at least one refrigeration demand. When both compartments no longer need refrigeration, the refrigeration demands are deactivated and the compressor is switched off.
Merloni Elettrodomestici 2. Defrost Heating Elements The purpose of the evaporator heating element is to melt any ice on the evaporating coil. The presence of ice is due to the condensation of moist air in the two compartments, when it comes into contact with the low temperatures on the evaporator. This ice compromises the heat exchange between the evaporator and the air, reducing the refrigeration properties in the two compartments of the appliance.
Merloni Elettrodomestici The elbow and chamber division heating elements allow the elimination of ice formed on those elements; such places are subjected to direct flows of cold air, that can produce ice which prevents correct air circulation. The four heating elements are connected in parallel and the electronic board controls them at the same time during the defrost phase.
Merloni Elettrodomestici The start and end of the defrost phase are controlled by the electronic board, taking into account: Start of defrost • total compressor On time from last defrost (on average11 hours). In any case the period between two defrosts will be: max. 30 hours, min. 8 hours. • duration of last defrost • number of door openings End of defrost • reaching the temperature of approx. 15 °C on the evaporator and in any case approx. 40 minutes after the start of defrost.
Merloni Elettrodomestici 3. Freezer fan The purpose of the freezer fan is to distribute the cold air, produced by the evaporator coil, inside the freezer compartment; the fan is located behind the evaporator coil. Particular situations • with Refrigerator Door open the freezer fan is not operated, even if the compressor is working, and is switched on again only when the refrigerator door is closed.
Merloni Elettrodomestici 4. Fridge fan The purpose of the fridge fan is to take the cold from freezer compartment to the inside of the refrigerator compartment. By means of special ducting it draws the cold air from the freezer and distributes it in the refrigerator compartment through openings on the multiflow. The fridge fan, located on the bottom of the compartment, is managed by the board.
Merloni Elettrodomestici 5. Fridge Lamps Inside the multiflow there are two lamps used to illuminate the refrigerator compartment. The lamps are connected in parallel, therefore the electronic board controls them at the same time. The lamps stay on when the refrigerator door is kept open in appliance On conditions, i.e.
Merloni Elettrodomestici 6. Thermal fuses Their function is to protect the combined unit from temperature increases caused by anomalous functioning of the heating elements, during the defrost phase. They are placed in contact with evaporator. If the temperature on the evaporator reaches 72 °C, the thermal fuses open, cutting off the feed to all the heating elements. They must be replaced in order to restore normal operation.
Merloni Elettrodomestici 7. Probes These are temperature sensors able to associate measurements in degrees centigrade with resistive values that are easily read and managed by the microprocessor on the board. • The Refrigerator Air Sensor, located inside the compartment, allows the temperature set by the user to be adjusted. It is managed by the electronic board and the user controls its adjustment.
Merloni Elettrodomestici • The Evaporator Sensor in contact with the evaporator is all-important for the duration and conclusion of the defrost phase. The electronic board processes the signal. If the sensor is cut off or short-circuited, defrosting is carried out in any case, though not according to the temperature but the times imposed by the electronic board. Like the other sensors, the evaporator sensor cannot be replaced. The “Autotest” function will confirm the malfunction.
Merloni Elettrodomestici • The Ambient Temperature Sensor, located on the electronic board, measures the temperature of the room where the combined unit is working. This parameter is important for optimizing consumption.
Merloni Elettrodomestici Temperature °C Resistance Ohm Temperature °C Resistance Ohm 50 973 -12 16497 45 1181 -13 17429 40 1493 -14 18420 35 1765 -15 19475 30 2176 -16 20596 25 2700 -17 21791 20 3360 -18 23063 15 4225 -19 24418 10 5348 -20 25862 9 5611 -21 27402 8 5888 -22 29045 7 6182 -23 30797 6 6491 -24 32668 5 6818 -25 34666 4 7164 -26 36800 3 7529 -27 39082 2 7916 -28 41521 1 8325 -29 44131 0 8758 -30 46921 -1 9216 -31
Merloni Elettrodomestici POSSIBLE CAUSE OF MALFUNCTION: Board management Monitoring circuit on the board Connection on the board Sensor wiring TESTING: General on appliance: carry out the check using the “Autotest” procedure; Wiring and component: check for continuity and short circuits; check the connections (connectors and terminals); check that the resistive values correspond to the values given by the manufacturer (heat the probe touching it with your hand where possible and check the variation in the
Merloni Elettrodomestici 8. Eeprom memory All the appliance functioning parameters are stored inside the Eeprom; incorrect communication between microprocessor and memory can seriously affect appliance operation and the user's adjustments. The Eeprom is located on the electronic board.
Merloni Elettrodomestici 9. Buzzer Buzzer operation is closely tied to the signalling and alarm functions. The buzzer is soldered onto the power board on the instrument panel.
Merloni Elettrodomestici 10. Display (when present) The display allows the user to check the status of the appliance and to receive this information: the display is soldered onto the Display board on the refrigerator door. POSSIBLE CAUSE OF MALFUNCTION: Microprocessor management Control circuit on the board Display Main board and Display board connection cable TESTING: General on appliance and component: with the appliance ON, check that the display is switched on correctly according to specifications.
Merloni Elettrodomestici 11. LEDs (when present) The LEDs allows the user to check status of the appliance and to receive this information: the LEDs are soldered onto the Power board on the control panel.
Merloni Elettrodomestici 12. Analysis of keys (models with display only) The keys allow the user to manage the appliance: they are soldered onto the Display board on the freezer door.
Merloni Elettrodomestici 13. Analysis of knobs and keys (STANDARD models only) The keys and knobs allow the user to manage the appliance: they are soldered onto the board on the appliance control panel.
Merloni Elettrodomestici 5 ELECTRONIC BOARDS NF COMBINED UNITS WITH DISPLAY DISPLAY BOARD FR DOOR STANDARD NF COMBINED UNITS Technical Manual Language Issue/Edition FULL NO FROST COMBINED UNIT (2003) GB 04-10-28/01 Page 31-43
FRIDGE AIR 1 RES. EVAP. 2 1 1 RES. GOCC. TF 2 1 RES.DIV.
L = LINE N = NEUTRAL CO = COMPRESSOR PTC = PTC RELAY RH = THERMAL RELAY C(*) = START CONDENSER X CPS HIGH EFFICIENCY SND-1-2-3 = SENSORS LEGEND N SND3 SND2 ---- ---- TF1 R6 ---- ---- TF = THERMAL FUSE LI = FRIDGE LAMP MV FR/FZ = FRIDGE/FREEZER FAN TF2 m CO c s ELECTRONIC SCHEDA ELETTRONICA BOARD R1 SND1 LI LI R2 ---- RH MV FR R1 = DRIP TRAY HEATING ELEMENT R2 = EVAPORATOR HEATING ELEMENT R3 = CHAMBER DIVISION HEATING ELEMENT R4 = MULTIFLOW HEATING ELEMENT (when present) R5 = CONTRO
Merloni Elettrodomestici 8 RECOMMENDED PROCEDURE ELECTRONIC APPLIANCES FOR TESTING THE START ? End of check OK General testing on the appliance KO Action KO Testing EEPROM If EEPROM is not installed go on to the next check OK Repeat procedure from the beginning Action (when possible) KO Testing the wiring harness and the connections If there is no wiring harness go on to the next check OK Repeat procedure from the beginning Action KO If component on the board: go on to the next check
Merloni Elettrodomestici 9 AUTOTEST This helps with a quick check of the loads, which otherwise are difficult to activate, as well as of the probes and the EEPROM memory. N.B.: before using the Autotest it is advisable to check the correct operation of the refrigerator lamps and the buzzer which are used for signalling possible malfunctions.
Merloni Elettrodomestici 10 ALARMS Alarm Management The appliance can provide the user with information on operational malfunctions: • Refrigerator door open too long • High temperature inside Freezer compartment The indications and procedures for exiting refrigerator door open alarm situations are given in the table: DISPLAY MODELS Conditions Door open > 2 minutes Door open > 4 minutes Door open > 6 minutes STANDARD MODELS Exiting the alarm condition Signalling Signalling Exiting the alarm condi
Merloni Elettrodomestici 11 “DEMO MODE” FUNCTION (DISPLAY MODELS ONLY) The DEMO MODE can be activated by keeping the MODE, ADJUST SELECT + and ADJUST SELECT - buttons pressed at the same time for more than 3 seconds, starting from an initial appliance OFF condition. Activating this function makes the user interface (display and keys) completely accessible without controlling any load (compressor, refrigerator, freezer fan, heating elements), irrespective of the status of the appliance.
Merloni Elettrodomestici 13 “HOLIDAY” FUNCTION This function offers temperatures optimized for preserving foods with the lowest permissible consumption in case of minimum use of the refrigerator compartment: particularly in the case of medium-long holidays when the freezer can remain full and with the refrigerator empty.
Merloni Elettrodomestici 14 “SUPER FREEZE” FUNCTION This function allows all foods placed in the freezer to be frozen in the best possible way (also for best preserving the qualities of the frozen foods). Activating this function forces the compressor to stay on continuously in order to have maximum freezing power for the freezer compartment.
Merloni Elettrodomestici The SUPER FREEZE function (irrespective of 24h or 48h) can be deactivated by a further action on the display (or the special key, for standard models); another exit mode is also reaching of the max. activation temperature appraised for the function: 24h or 48h according to the mode activated. For the SUPER FREEZE 24h function only, exiting is also provided for when a given temperature is reached in the freezer (0 °C for 254 minutes).
Merloni Elettrodomestici The SUPER COOL function can be deactivated by a further action on the display, or by means of the special key in standard models; another exit mode is also the completion of the number of cycles with the new thermostatting thresholds. At the moment of deactivation the signalling on the display stops and the user adjustment prior to activation of the SUPER COOL function is reactivated.
Merloni Elettrodomestici Switching off the appliance (ON/OFF key on the display) automatically involves deactivation of the function. Entering one of two alarms modes automatically involves deactivation of the function; the signalling (display and buzzer) for removing the bottle from the freezer compartment is in any case activated. Activation of the HOLIDAY function deactivates the ICE PARTY function, activating the relevant message to remove bottle, on the display.
Merloni Elettrodomestici Merloni Elettrodomestici S.p.A. 47 Viale Aristide Merloni, Fabriano - 60044 - Italy tel. 0732/6611 - telex 560196 - fax 0732/662954 www.Merloni.com All parts quoted in this document are the property of Merloni Elettrodomestici S.p.A. All rights reserved. This document and the information it contains are supplied without liability arising from possible errors or omissions. No part can be reproduced, used or copied without written permission or a contractual clause.
