A sudden stop of the compressor or its humming without starting often indicates a failure of the starting device. In household refrigerators of the brand Nord this unit is responsible for supplying a starting pulse to the motor winding. If you are faced with a similar problem, then replacing the part yourself can save a significant amount of money and time waiting for a technician.
However, before starting work, you need to make sure you have basic skills in working with electricity. Relay is not just a switch, but a mechanism that requires precise connection according to the diagram. An installation error can lead to combustion of the compressor, so it is important to act consistently and carefully.
In this article we will analyze the process of diagnosing and replacing the start control element for various models Nord. You will learn how to properly remove the old unit, determine the type of fault and install a new component, ensuring stable operation of the refrigeration unit.
Diagnostics of a malfunction of the starting device
The first sign of a breakdown is a characteristic clicking sound that is heard every few minutes. The compressor tries to start, hums for 2-3 seconds, then a click is heard and the motor stops. This triggers thermal protection, since starting relay does not close the starting winding circuit or does not open it after start.
Sometimes the refrigerator may turn on on the second or third attempt, but will work intermittently. In such cases, traces of soot or melted contacts are often visible inside the relay housing. If the device emits a burning smell or is visibly damaged, its replacement is inevitable.
⚠️ Attention: If the situation has not changed after replacing the relay, the problem may lie in the compressor itself (turn-to-turn short circuit) or in the wiring. Do not install new parts blindly without checking the resistance of the motor windings.
For an accurate diagnosis, you can open the relay casing and inspect the insides. In models with a posistor (solid-state relay), there should be no cracks in the ceramic element. In induction models, the contacts should be clean, and the coil should have no signs of overheating. Multimeter this will help to ring the circuit for breaks.
Necessary tools and safety measures
Working with electrical equipment requires strict adherence to the rules electrical safety. Before starting any manipulations, you must completely de-energize the refrigerator by unplugging the cord from the outlet. Even briefly touching live parts under voltage can be life-threatening.
To perform the replacement, you will need a minimum set of tools that most men have in their homes. It is important that the screwdrivers have insulated handles and that the pliers are in good working order. The presence of a flashlight will improve visibility in the darkened niche of the compressor compartment.
List of necessary equipment:
- 🔧 Flat-head screwdriver (for removing terminals and covers).
- 🔧 Phillips screwdriver (if the casing is secured with screws).
- 🔧 Pliers or pliers (for fixing the wires).
- 🔧 Multimeter (to check the continuity of the circuit).
- 🔧 Flashlight or portable lamp.
It is also recommended to prepare a clean rag for wiping the contacts from dust and possible oil. If water or condensation is found in the compressor niche, they must be carefully removed before starting work, as moisture can cause a short circuit.
☑️ Preparation for repair
Removing the old relay and preparing for installation
Access to the starter device in refrigerators Nord usually located in the lower rear part of the case. The compressor is closed with a metal or plastic casing, which is secured with latches or screws. Carefully remove the protection so as not to damage the tubes and wires.
At the end of the compressor you will see a plastic box placed directly on the motor terminals. This is exactly what we are looking for start relay. It is secured with a metal bracket or spring clip. Loosen the clamp and carefully pull the device down, disconnecting it from the compressor contacts.
It is important to remember or photograph the position of the wires before disconnecting them. In different modifications Nord color markings may differ. Typically, three wires go to the relay: phase, neutral and ground (or wire to the thermostat). Disconnect the terminals using a flat-head screwdriver if they are tight.
What to do if the relay is stuck?
Sometimes the contacts oxidize so much that the relay is difficult to remove. In this case, you cannot use force or jerk - you can damage the compressor terminals. Gently rock the device from side to side while pulling it down. If possible, drop a little alcohol on the contacts to soften the oxides.
After dismantling, inspect the seat on the compressor. Contacts must be clean and free of corrosion. If there is oxide on the motor terminals, carefully clean them with fine sandpaper or an eraser. This will ensure reliable contact with the new device.
Connection diagram and relay types for Nord
Refrigerators Nord were equipped with different types of starting devices depending on the year of manufacture and model of the compressor. The most common are induction relays (with a coil and a moving core) and posistor (solid-state) relays. Their connection diagrams differ.
In induction models, current passes through the coil, creating a magnetic field that lifts the core and closes the contacts of the starting winding. As the speed increases, the current drops and the core drops, opening the circuit. PTC relays operate by changing the resistance of a ceramic element when heated by current.
| Relay type | Appearance | Principle of operation | Frequent faults |
|---|---|---|---|
| Induction (RT, RTP) | Black plastic case, coil inside | Electromagnetic disconnection | Burning of contacts, jamming of the core |
| Posistor (PTC) | White or gray case, inside a ceramic disk | Thermal change in resistance | Destruction of a posistor, loss of properties |
| Combined | Complex design with a thermal relay | Combines start and protection | Failure of the bimetallic plate |
When purchasing a new part, be sure to compare the markings of the old device. For Nordov relays of the series RTK-1, RTP-1 or their modern analogues are often suitable. Pay attention to the direction of installation: on the case there is usually an arrow UP or an inscription TOPindicating which side the device should face up.
The process of installing and connecting contacts
Installation of a new relay begins with its correct positioning on the compressor terminals. The relay pins must fit tightly into the corresponding sockets on the engine. If you are using an induction relay, make sure that it is positioned strictly vertically, as indicated in the diagram in the technical data sheet.
After putting it on the compressor, it is necessary to secure the device with a metal bracket or bar. It prevents vibration and contacts from moving away during operation. Then start connecting the wires. Insert the terminals into the corresponding connectors on the relay body until a characteristic click is heard.
Wire connection order (standard diagram):
- ⚡ The phase wire (usually brown, red or black) is connected to the contact going to the starting winding or thermostat.
- ⚡ The neutral wire (blue) goes to a common point or directly into the circuit.
- ⚡ The ground wire (yellow-green) is connected to the case or a special terminal.
It is important not to confuse the wires coming from the thermostat and from the power plug. If in doubt, it is better to test the circuit with a multimeter. One probe is placed on the plug, the other on the input contact of the relay. When the thermostat circuit is closed, the device will show zero or low resistance.
⚠️ Attention: Make sure that the wires do not touch hot parts of the compressor or sharp metal edges. During vibration, the insulation can be worn away, which will lead to breakdown on the housing and electric shock.
First start-up and performance check
After assembling the structure and checking all connections, you can begin testing. Plug in the refrigerator. In the first seconds you can hear a hum, which after 1-3 seconds should be replaced by the even hum of a running engine. A click when starting is normal (the mechanism for disconnecting the starting winding is activated).
If the compressor starts and runs smoothly, without extraneous knocks and vibrations, it means connection diagram it is assembled correctly. Touch the relay body after 10-15 minutes of operation - it may warm up slightly, but it should not be so hot that it is impossible to touch.
If you hear a click, but the motor does not start, or the humming stops immediately, immediately turn off the device from the network. You can try restarting no earlier than after 5-10 minutes, when the thermal relay has cooled down and returned to its original state. Repeated attempts to start may damage the windings.
Typical errors when replacing yourself
One of the most common mistakes is ignoring the orientation of the relay in space. Many models work correctly only in a vertical position. Installation upside down or on its side will result in the contacts not opening and the starting winding will burn out.
Another common problem is poor contact at the terminals. If the wire is not inserted completely or is oxidized, transition resistance will arise at the connection point. This will cause local heating, melting of the plastic and repeated failure. Always clean the contacts and crimp the terminals tightly.
Also, novice craftsmen often forget about the thermal regime. Installing a relay with unsuitable cut-off current characteristics will result in the protection tripping too early or, conversely, not tripping in the event of an overload. Always check the marking compressor and the manufacturer's recommendations.
You should not skimp on the quality of spare parts. Cheap Chinese analogues may not have the proper service life and will fail in a month. It is better to buy an original product or a certified analogue from a well-known brand to ensure a long service life of the refrigerator Nord.
Can an old relay be repaired rather than replaced?
Theoretically, an induction relay can be disassembled and the contacts can be cleaned of carbon deposits. However, this is a temporary measure. Mechanical wear and changes in the properties of metal will not go away over time. For reliable operation of a refrigerator that stores food, it is better to replace the entire assembly.
Why does the new relay burn out after a few days?
There may be several reasons: the compressor itself is faulty (difficult start), low voltage in the network, or a relay with the wrong cut-off current has been selected. A short circuit in the refrigerator wiring is also possible.
Where can I find the markings of a suitable relay?
The markings are on the plastic body of the relay itself (for example, RTK-1, 100N). Information can also be found in the technical documentation for the refrigerator or on the compressor nameplate, which indicates the type of starting device required.
Is it dangerous to change the relay yourself?
If you follow the electrical safety rules (de-energizing the device), the risk is minimal. The main danger is electric shock when the device is plugged in or damage to the compressor due to careless installation.