Electrolux NOFROST Refrigerators Service Manual
Publication No. 599 35 61-04
1. Introduction
This manual describes the NOFROST models with the modification of the electric wiring which is now external. The connectors inside the freezer compartment have been removed, therefore, the electrical connections of the evaporator battery have been carried out directly inside the terminal board of the electromechanical timer which is placed in the compressor compartment. The electrical connections of the fan have been carried out directly inside the terminal board of the compressor.
There are three basic models which differ from each other only for the volume: 260 litres (ex C9, pnc 925886...), 262 litres (ex C10, pnc 925887...) and 290 litres (ex C11, pnc 925888...). The versions of the various models are R134a and R600a.
The modification is handled with the ELCs:
| pnc | Date | Brand | Model | Refrigerating gas |
|---|---|---|---|---|
| 92588660302 | 20021220 | Tricity Bendix | TB112FF | R134a |
| 92588665101 | 20021220 | Zanussi | ZX57/3W | R600a |
| 92588665301 | 20021220 | Zanussi | ZX57/3SI | R600a |
| 92588665601 | 20021224 | Zanussi | CZX165W | R600a |
| 92588665701 | 20030428 | Zanussi | CZX165SI | R600a |
| 92588666000 | 20030606 | Zanussi-Electrolux | ZEBF249W | R600a |
| 92588670000 | 20021220 | Privileg | 672.700 2/40032 | R600a |
| 92588670100 | 20030606 | Zanussi-Electrolux | CZC16/9FA | R600a |
| 92588670300 | 20030321 | Zanussi-Electrolux | ZEBF250W | R600a |
| 92588760103 | 20021220 | Electrolux | ER7626B | R134a |
| 92588765101 | 20021220 | Zanussi | ZX55/4W | R600a |
| 92588765301 | 20021224 | Zanussi | ZX55/4SI | R600a |
| 92588765500 | 20030425 | Electrolux | ER7626/1B | R600a |
| 92588770000 | 20030418 | Zanussi-Electrolux | ZEBF262W | R600a |
| 92588860104 | 20021220 | Electrolux | ER7926B | R134a |
| 92588865101 | 20021220 | Zanussi | ZX56/4W | R600a |
| 92588865301 | 20021220 | Zanussi | ZX56/4SI | R600a |
| 92588865500 | 20030425 | Electrolux | ER7926/1B | R600a |
| 92588870000 | 20021220 | Privileg | 672.694 7/40033 | R600a |
| 92588870100 | 20030418 | Zanussi-Electrolux | ZEBF290W | R600a |
| 92588870200 | 20030606 | Zanussi-Electrolux | ZEBF290SI | R600a |
The new evaporator batteries are not interchangeable with the old ones. The evaporator batteries for the R134a version feature only one defrosting heater, while the evaporator batteries for the R600a version feature two defrosting heaters connected in parallel for safety reasons of the product. The thermal protections are connected in series to the defrosting heaters and are cabled together, therefore, they are not interchangeable singularly. An assembly spare part no. is available in case of failure of a thermal protector or of a defrosting heater.
2. Refrigeration Circuit
Diagram description: The refrigeration circuit consists of a compressor (1), capacitor (2), filter (3), capillary tube (4), heat exchanger (5), and battery evaporator (6).
3. Electric Wiring
3.1. R134a Version
Diagram description: This diagram illustrates the electrical connections for the R134a version of the NOFROST refrigerators. Key components include the terminal board of the freezer compressor (2), motor protector (5), refrigerator thermostat (6), armoured defrosting heater (9), refrigerator lamp (13), light switch (15), battery fan (24), timer (25), safety thermal switch (+40°C) (26), defrosting cut-out switch (+10°C) (27), and running capacitor (28). Wire color codes are provided: yellow-green (a), brown (b), blue (c), white (d), black (e), grey (f).
3.2. R600a Version
Diagram description: This diagram shows the electrical connections for the R600a version. It includes components similar to the R134a version but also features a stylus defrosting heater (9), an armoured defrosting heater (9a), and an ON/OFF pilot lamp (21). Wire color codes are the same.
4. Functional Diagram
4.1. R134a Version
Diagram description: A simplified functional schematic of the electrical system for the R134a version, illustrating the interplay of components like the timer, compressor, fan, and heating elements.
4.2. R600a Version
Diagram description: A simplified functional schematic for the R600a version, similar to the R134a version but reflecting the specific component differences.
5. Operation
5.1 Normal
Description of normal operation: Humidity accumulates on the evaporator battery due to air circulation, preventing frost on food. During normal operation, the timer (25) closes contacts 3-4, powering the compressor and fan circuits for approximately 14 hours. Arrows in the diagram indicate the current path.
5.2 Defrosting
Description of defrosting operation: After about 14 hours, the timer (25) switches from contacts 3-4 to 3-2, disconnecting the compressor and fan and activating the defrosting heaters (9 and 9a). The R600a version has two heaters connected in parallel for safety. After 36 minutes of defrosting, the timer returns to contacts 3-4. The defrosting process is controlled by temperature cut-out switches: the defrosting cut-out switch (26) at +10°C and the safety thermal switch (27) at +40°C. Arrows in the diagram show the current path.
6. Components
6.1 Control Panel
The control panel includes: a pilot lamp (B), a thermostat knob (T), and a light button (P).
6.2 Refrigerator Compartment
The refrigerator compartment features: a flap (C) controlled by knob (M) to regulate cold air flow, and a lamp holder (A).
6.3 Freezer Compartment
The freezer compartment contains: a fan (D), thermal overload cut-outs (E), an evaporator battery (F), and defrosting heaters (G).
Table A: Type of Thermal Overload Cut-Out
| Type of Thermal Overload Cut-Out | Operating Temperature | |
|---|---|---|
| Opening | Closure | |
| Defrosting | +8°C | -1°C |
| Safety | +40°C | +30°C |
Table B: Component Data
| pnc | Refrigerating gas | Voltage | Resistance | Power | Notes |
|---|---|---|---|---|---|
| 925886xxx | R134a | 240 V | 242 Ω | 238 W | |
| 925886xxx | R600a | 240 V | 213 Ω (see notes) | 271 W | Total value of the 2 resistances |
| 925887xxx | R134a | 240 V | 220 Ω | 262 W | |
| 925887xxx | R600a | 240 V | 207 Ω (see notes) | 278 W | Total value of the 2 resistances |
| 925888xxx | R134a | 240 V | 220 Ω | 262 W | |
| 925888xxx | R600a | 240 V | 207 Ω (see notes) | 278 W | Total value of the 2 resistances |
6.4 Compressor Compartment
The compressor compartment houses the timer (H) located at the back of the appliance. The timer shaft cam can be manually rotated clockwise using a screwdriver to switch contacts 3-4 and 3-2.
Diagram description: A view of the timer contacts shows terminals 1, 2, 3, 4. The electric circuit of the timer is depicted, indicating that contact 4 is for the compressor and contact 2 is for the heaters. A legend shows states for 'CONTACT CLOSED' and 'CONTACT OPENED'. Timer cycle times are given: Time "A" (total cycle) is 14 hours 26 minutes, and Time "B" (defrosting) is 36 minutes.
Explanation of timer operation: Rotating the timer shaft clockwise produces two audible snaps indicating contact closure. The period between the 1st and 2nd snap represents a minimum run, while the period between the 2nd and 1st snap is longer. Warning: For testing 'normal' operation, rotate the timer cam to the 2nd snap (closing 3-4). For testing 'defrosting' operation, rotate to the 1st snap (closing 3-2).
7. Accessibility
7.1. Control Panel Accessibility
To access control panel components (thermostat, pilot lamp, light button), follow these steps: 1. Remove the 2 fixing screws from the hinges. 2. Remove the 2 fixing screws located behind the appliance. 3. Push the top forward.
Diagram description: Illustrates the steps for accessing the control panel, showing screw removal and pushing the top panel.
7.2. Refrigerator Compartment Accessibility
To access the flap: Remove the caps covering the two screws. Loosen the two screws. The thermostat bulb is inserted into the rear of the flap.
Diagram description: Shows how to remove caps and screws to access the refrigerator compartment flap, with a detail of the thermostat bulb insertion.
7.3. Freezer Compartment Accessibility
Accessing freezer compartment components requires removing protection. The evaporator battery (F) is secured by two lateral clips (L) and three hooks (N) at the bottom, removable with a screwdriver. Thermal overload cut-outs (E) are connected to the defrosting heaters and are fitted to the evaporator battery pipes; they are not available as single spare parts.
Diagram description: Shows the freezer compartment layout with fan (D), evaporator battery (F), thermal overload cut-outs (E), and defrosting heaters (G). It also details the fixing points of the evaporator battery (L, N) and the connection of thermal overload cut-outs.
After detaching the battery, it can be bent to access the heaters, taking care of the pipes. The defrosting heaters are attached to wings using three clamps (J). To replace them, unhook the clamps with pliers (they can be reused) and remove the heaters, avoiding deformation. The fan is secured with 2 screws.
8. Troubleshooting
WARNING! Unplug the appliance before operating.
Discharged Circuit
In case of refrigerant gas leak, troubleshooting should include checking traditional welds, as well as junctions with LOKRING rings of pipes (battery-capillary R) and battery-return pipe (S), and welds of cylinder (T) for R600a versions.
Diagram description: Shows internal components related to the refrigerant circuit, highlighting points R, S, and T.
Excessive Ice on the Battery
If the rubber valve remains open, humid air from the freezer compartment enters and forms excessive ice on the battery. This can happen if foreign bodies are present or if the valve loses elasticity. In the first case, remove foreign bodies; in the second, replace the rubber valve.
Failed Defrosting
If no defrosting cycle occurs, possible causes include:
| Sequence n° | Cause Possibili | Possible Causes | How to Verify |
|---|---|---|---|
| 1 | One or both defrosting heaters are interrupted | Freeze the battery, then unplug the appliance, disconnect the connectors of the heaters and check with the tester the correct resistance value to the connector clamps. | If the value of the resistances does not correspond to the technical data, replace the heaters and overload cut-outs assembly. |
| 2 | One or both thermal overload cut-out switches are open | Freeze the battery, then unplug the appliance, disconnect the connectors of the heaters and check with the tester the correct resistance value to the connector clamps. | If the value of the resistances does not correspond to the technical data, replace the heaters and overload cut-outs assembly. |
| 3 | Timer blocked or faulty | Unplug the appliance, place the thermostat knob on ON, then access timer box and measure with the tester the electrical continuity: a) between the clamp 1 of timer and the line clamp of the feeding plug; b) between the clamp 3 of timer and the clamp of the feeding plug neutral wire. | If the resistance values of the two measures [a) and b)] are 0 Ω, then replace the timer. |
Burn Out Lamp
After replacing a burnt-out lamp, verify the correct operation of the light button (P) by manually activating it. Then, try again by activating the light button via the refrigerator door closure and check if the lamp switches off when the door's magnetic seal is slightly moved.
Warning: The lamp holder seal (Q) is a critical safety component. It must be reinserted into the lamp holder after replacing the lamp.
Diagram description: Shows the lamp holder (Q) and its seal, illustrating the replacement process.
