The start relay is a small but critical device in the refrigerator, which is responsible for starting the compressor and protecting it from overloads. When it fails, many users wonder: is it possible to do without it and turn on the unit directly? The answer is ambiguous. On the one hand, this is technically possible under certain conditions. On the other hand, such a start is fraught overheating of the compressor windings, reducing its service life or even complete failure.
In this article we will analyze, how to temporarily start a refrigerator without a start relay, what tools will be needed for this, and why this method should be as a last resort. You will also learn how to recognize a faulty relay, which models of compressors are more resistant to such a start, and what to do if the refrigerator does not cool after this.
⚠️ Warning: Perform all manipulations with the electrical circuits of the refrigerator only when it is turned off nutrition! Working with high voltage without the proper skills can lead to electric shock or fire.
Signs of a faulty start relay
Before trying to start a refrigerator without a relay, make sure that it is the problem. Typical symptoms of a malfunction:
- 🔌 The refrigerator does not turn on at all (there are no sounds of the compressor, the indicators do not light).
- ⚡ The compressor tries to start, but immediately turns off with a characteristic click.
- 🔥 The relay emits a burning smell or traces are visible on it reflow.
- 🕒 The refrigerator is unstable: it turns on and off for no apparent reason.
To confirm the diagnosis, you can check the relay with a multimeter. To do this:
- Disconnect the refrigerator from the network.
- Remove the relay cover (usually it is secured with latches or screws).
- Test the contacts for an open or short circuit (the resistance between the terminals should be within
20–50 Ohmfor a working relay).
If the relay is clearly burned out, it must be replaced. However, in situations where replacement is temporarily impossible (for example, at night or on weekends), you can try to start the compressor directly.
What is a starting relay and why is it dangerous without it
The starting relay performs two key functions:
- Start the compressor. At the moment of start, the current in the windings can exceed the rated one 5–7 times. The relay briefly connects start windingto create the necessary magnetic field.
- Overload protection. If the compressor cannot start (for example, due to high pressure in the system), the relay opens the circuit, preventing overheating.
Without a relay, the compressor loses this protection. The consequences can be serious:
| Risk | Consequences | Probability |
|---|---|---|
| Overheating of the starting winding | Insulation burnout, interturn short circuit | High |
| Compressor jamming | Complete failure, need for replacement | Medium |
| Damage to the thermostat | Incorrect operation of the refrigerator even after repair | Low |
| Fire | Fire of insulation or contacts | Very low (but possible!) |
Critical information: Modern compressors with built-in thermal protection (for example, models Embraco EG or Secop/Danfoss NLcan operate for a short time without a relay, but even they are not designed for long-term operation in this mode.
Step-by-step instructions: how to start a refrigerator without a relay
If you decide to take a risk and start the compressor directly, follow these instructions. Remember: this is a temporary solution and can only be used to check the operation of the compressor or in emergency cases!
Disconnect the refrigerator from the network
Remove the cover of the start relay
Check the integrity of the wires and contacts
Prepare insulated tools (screwdriver, pliers)
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Step 1. Access to compressor contacts
Remove the starting relay from the compressor. It is usually secured with latches or screws. Under it you will see three pins:
C(Common) - common contact;S(Start) - starting winding;R(Run) - working winding.
Step 2. Direct connection
You need to connect the contacts C i R directly, and then briefly (for 1-2 seconds!) touch the contact S to C. To do this:
- Use a screwdriver with an insulated handle or a wire with stripped ends.
- Connect one end of the wire to
C, the other toR. - Plug in the refrigerator.
- Connect briefly
SandC(you should hear a click and the compressor will start).
Step 3. Monitoring operation
If the compressor starts, monitor it operation:
- 🔊 Normal sound: uniform humming without extraneous noise.
- ⏱ Operating time: no more than 10–15 minutes in this mode!
- 🌡 Compressor housing temperature: should not exceed
60–70°C.
Which refrigerators can be started without a relay (and which cannot)
Not all compressors are equally resistant to starting without a starting relay. Here is a brief classification:
| Compressor type | Brands/models | Possibility of starting without a relay | Risks |
|---|---|---|---|
| Linear (old style) | Danfoss NL, Tecumseh AE | Possible (short term) | High starting current, risk of overheating |
| Inverter | LG Inverter, Samsung Digital Inverter | Impossible | Complex electronics, requires precise control |
| With built-in protection | Embraco EG, Secop (Danfoss) NT | Possible (up to 30 minutes) | Minimum risk while observing the operating time |
| Rotational | Mitsubishi, Panasonic | Impossible | Sensitive to starting currents |
⚠️ Attention: Inverter refrigerators (LG, Samsung, Hitachi) cannot be started without a relay! Their compressors are controlled by electronic boards, and direct connection will lead to a firmware failure or failure of the power module.
What to do if the refrigerator starts but does not cool
If the compressor works, but the refrigerator does not freeze, there may be reasons as follows:
- ❄️ Freon leakage. Without refrigerant, the compressor will hum, but the temperature will not drop.
- 🔧 Seizing valve. The system may have a blockage in the capillary tube or filter drier.
- 🌡 Thermostat malfunction. If the temperature sensor does not give a signal, the compressor will work continuously, but without result.
- 🔌 Low mains voltage. When the voltage is lower
190 Vthe compressor may run "idle".
To diagnose the problem:
- Check the voltage in the outlet with a multimeter.
- Touch the condenser (rear grill of the refrigerator): if it is cold, most likely not freon.
- Listen to the compressor: if it works non-stop, but does not freeze, this is a sign of a leak or blockage.
How to check for freon leaks at home?
The easiest way is to apply a soap solution to the soldering areas of the tubes (especially in the area of the compressor and condenser). If bubbles appear, there is a leak. However, this method only works for significant damage. For accurate diagnosis, you need an electronic leak detector or calling a technician.
Alternative starting methods (if the relay is burned out)
If the starting relay is burned out, but you urgently need to save the products, consider these options:
- 🔄 Replacement with a universal relay. Suitable models RBM-1, DANFOSS 103N0012 or Embraco ER3800. They are compatible with most household compressors.
- 🔌 Using a starting capacitor. Connecting a capacitor (
15–40 µF) in parallel with the starting winding can help start the compressor without a relay. Connection diagram:C → Capacitor → S. - ⚡ Connection via a soft starter. Device type PST-10 or SoftStarter smoothly increase the voltage, reducing the load on the windings.
⚠️ Attention: When using a capacitor, it is important to select the correct capacitance. Too large a capacity will lead to overheating of the windings, too small - the compressor will not start. For most household refrigerators, a capacitor is suitable 25–35 μF.
When to call a professional, and when you can do it yourself
Here are clear criteria for when to turn to a professional:
| Situation | Can I handle it myself? | Recommendation |
|---|---|---|
| The relay is burned out, but the compressor is OK | Yes | Replace the relay to a similar or universal one |
| The compressor hums, but does not start | Partially | Try starting without a relay (for a short time) |
| The refrigerator does not freeze after starting | No | Need a diagnostician (possible freon leak or blockage) |
| Inverter refrigerator | No | Independent repair will lead to damage to the electronics |
| Visible damage to the tubes or oil leakage | No | Requires soldering and refilling with freon |
If you are not confident in your skills, it is better to call a specialist. The average cost of replacing the start relay at a service center is 1500–3000 rubles (depending on the refrigerator model). This is cheaper than repairing or replacing the compressor after an unsuccessful experiment.
FAQ: Frequently asked questions about starting a refrigerator without a relay
Is it possible to constantly operate a refrigerator without a start relay?
No. Without a relay, the compressor is deprived of overload protection, which will lead to its rapid wear. The maximum permissible operating time in this mode is 15–30 minutes for diagnostics.
What happens if you mix up the contacts when connecting directly?
If you switch places S and R, the compressor will not start, but no serious damage will occur. If you apply voltage only to the starting winding (C-S without R), it will overheat in a few seconds.
How to check if the compressor is working if the relay is burned out?
Test the windings with a multimeter:
- Resistance between
C-R:10–30 Ohm; - Resistance between
C-S:15–40 Ohm; - Resistance between
R-S: the sum of the two previous ones values.
If the readings are very different or there is a break, the compressor is faulty.
Is it possible to use a relay from another refrigerator?
It is possible if it meets the following parameters:
- Compressor type (linear/inverter);
- Power (indicated on the compressor nameplate);
- Number of contacts (3 or 4).
Universal relays (for example, RBM-1) are suitable for most household models.
Why does the compressor start without a relay, but turns off after 5 minutes?
This is a sign that the compressor is triggered. It turns off the power when the windings overheat. In this case, further attempts to start without a relay will lead to breakdown. internal thermal protection compressor. It turns off the power when the windings overheat. In this case, further attempts to start without a relay will lead to failure.