Starting autonomous refrigeration equipment based on the DAF 105 chassis requires the driver or mechanics of a clear understanding of the sequence of actions, since these systems differ significantly from household analogues. Refrigerated truck - this is a complex unit powered by a diesel engine, and an incorrect switching procedure can lead to serious damage to the compressor or electronic control unit. Before starting operation, you must make sure that all connecting couplings are tight and the refrigerant level is within normal limits.
Unlike household models, the condition of fuel system the refrigerator itself is critically important here. Often the cause of a startup failure is not the electrics, but the airing of the fuel line or the lack of diesel fuel in the tank of the refrigeration unit. Primary starting after a long period of inactivity requires mandatory pumping of the fuel system manually or through a special pump mode. Ignoring this stage will lead to the engine seizing and stalling, and the control unit will display an error of low oil pressure or lack of rotation.
Modern control systems, such as Thermo King or Carrier, often installed on the DAF 105, have their own nuances in the menu. The driver needs to not only turn the key, but also set the operating parameters correctly. Errors in settings can lead to the installation running idle without cooling the cargo, or, conversely, freezing the product. Let's look in detail at each stage of preparing and activating the system.
Preliminary diagnostics and visual inspection
Before trying to turn on refrigeration unitit is necessary to conduct a thorough external inspection. Mechanical damage to the radiators, condenser or evaporator can negate all starting attempts. Vibrations when driving a DAF 105 truck contribute to loosening of the fastenings, so checking the integrity of the casings and pipes is a mandatory first step. Any freon or oil leak must be repaired before voltage is applied.
Particular attention should be paid to electrical connections. Oxidized contacts or frayed wires are a common problem on commercial vehicles. Check the condition of the battery terminals, as the inrush current of the refrigerator starter is quite high. If the voltage in the on-board network is below normal, the electronic control unit (ECU) may simply not start or go into protection mode.
⚠️ Attention: It is prohibited to turn on the unit if obvious signs of oil or refrigerant leakage are detected. Operating the compressor without lubrication or with a low level of freon will lead to irreversible failure of expensive components in a matter of minutes.
Also check the tension of the drive belts. If the alternator or compressor belt is sagging or cracked, it must be replaced. Weak tension will lead to slippage, overheating and rapid wear. A visual inspection takes no more than 10 minutes, but saves you from hours of downtime and expensive repairs along the way.
☑️ Pre-start inspection of DAF 105
Preparation of the fuel system and engine
Refrigerator engine installed on DAF 105 is extremely sensitive to fuel quality and the presence of air in the system. Before starting, make sure that the fuel tank is filled with diesel fuel of the appropriate season. In winter, the use of summer diesel fuel will lead to waxing of the filters and the impossibility of starting. Fuel filter must be replaced according to the regulations, since its contamination creates a vacuum that the fuel pump is not able to overcome.
If the unit has not been in operation for a long time, air could accumulate in the fuel rail. To remove it, many models have a manual pump or a special mode in the controller menu. The pumping process takes time: it is necessary to achieve a stable supply of fuel without bubbles in the transparent return hose. Without this, the engine will operate unstable
After preparing the fuel, check the level engine oil. The level on the dipstick should be between the MIN and MAX marks. Running the engine with a low oil level causes scuffing of the bearings and crankshaft. Also check the condition of the air filter: a clogged filter restricts the air supply, which leads to a rich mixture and smoky exhaust.
What will happen if you start the engine with air in the fuel?
Starting the engine with air in the fuel system will lead to uneven operation, detonation and possible breakdown connecting rod due to water hammer or running on a lean mixture. Long-term operation on diesel fuel with air can also cause overheating of the high-pressure fuel pump (HPF), since diesel fuel acts as a lubricant for the plunger pairs.
Activation algorithm and controller settings
The process of activating the refrigeration unit begins with the supply of power to the control panel. On the DAF 105, the power button is usually located on the front panel of the unit or in the driver's cab, depending on the configuration. After switching on, the display lights up and the system undergoes self-diagnosis. At this moment controller checks pressure, temperature sensors and circuit integrity.
Next you need to select the operating mode. For most cargoes, cooling (Cool) or freezing (Freeze) modes are used. It is important to set the temperature setpoint correctly. If it is necessary to maintain the temperature of the cargo, the appropriate mode is selected, but if the cargo is already frozen and you just need to keep it cold, the storage mode is selected. Incorrect selection of the mode will lead to temperature fluctuations inside the body.
After selecting the mode, press the engine start button. The starter will begin to crank the crankshaft. If the engine does not catch on the first try, do not keep the starter on for more than 10-15 seconds. Let it cool and try again after pumping the fuel. A successful start is characterized by the smooth sound of the diesel engine and the absence of vibrations.
Checking operation and monitoring parameters
After starting the engine, you need to make sure that the system switched to working mode. The compressor should begin to build up pressure, which can be heard by a characteristic sound and felt by the vibration of the pipelines. The controller display should show the current sensor readings. Compare the temperature at the outlet of the evaporator and in the body - the difference should be significant in the first minutes of operation.
Pay attention to the readings refrigerant pressure. Low suction side pressure may indicate a leak or faulty expansion valve (TEV). High pressure on the discharge side often indicates a dirty condenser or a faulty fan. Normal pressure values depend on the type of refrigerant and the ambient temperature.
| Parameter | Normal value (approximately) | Possible cause of deviation |
|---|---|---|
| Pressure suction | 1.8 – 3.5 Bar | Lack of freon, filter clogged |
| Discharge pressure | 12 - 18 Bar | Dirty condenser, air in the system |
| Oil temperature | 60 – 90 °C | Thermostat malfunction, engine wear |
| Engine speed | 1500 - 2200 rpm | Calibration failure throttle |
It is important to listen to the operation of the fans. They must turn on synchronously with increasing pressure or upon command from the controller. If the condenser fan does not work, the discharge pressure will quickly rise to the emergency value and the unit will shut down due to protection. Checking airflow (air flow) is a key diagnostic stage.
Typical errors and methods for eliminating them
The DAF 105 electronics are equipped with a self-diagnosis system that displays error codes on the display. The most common problem is a low fuel level or low oil pressure error. In the first case, re-bleeding of the system is required. The second is to check the oil level and the serviceability of the pressure sensor. Ignoring these signals can lead to engine seizure.
Temperature-related errors (High Temp or Low Temp) can occur when the sensors are faulty or when there is a real threat of cargo defrosting. If the sensor shows incorrect values, it must be replaced or calibrated. False readings can lead to damage to the cargo, so confidence in the electronics must be confirmed by manual measurement with a thermometer.
⚠️ Attention: If you receive an error code associated with High Pressure, stop the unit immediately. Continuing operation may result in ruptured pipes or damage to the compressor. Check the cleanliness of the radiator and the operation of the fan.
There are also communication errors between the controller and the engine. This may be caused by broken wires or oxidation of connectors. In such cases, the installation may not respond to commands from the control panel. Checking the integrity of the wiring harnesses and cleaning the contacts often solves the problem.
Recommendations for operation in different conditions
Operating a refrigerator in winter and summer has its own characteristics. In winter, it is important to use preheating or operate in warm-up mode so that the oil in the crankcase reaches operating viscosity. Starting a cold engine at high speeds is unacceptable. Also in winter, you should monitor the condition of fuel filters to avoid paraffin freezing.
In summer, the main enemy is overheating. It is necessary to regularly clean the condenser honeycombs from fluff, insects and dust. A clogged radiator will not be able to effectively cool freon, which will lead to a drop in performance and an increase in pressure. In hot weather, the intervals between maintenance should be reduced.
When working in mountainous areas or on long When climbing, monitor the engine temperature. The additional load on the generator and compressor can lead to overheating. In such conditions, it is advisable to reduce the driving speed or make stops to cool the unit.
Frequently asked questions (FAQ)
Why does the DAF 105 refrigerator not start the first time?
Most often the reason lies in airy fuel system or a discharged battery. It is also possible that the fuel may freeze in winter or that the glow plugs may be faulty. Fuel pumping and electrical checks are required.
How often do you need to change the oil in a refrigerator engine?
The oil is changed every 500-1000 operating hours, depending on the recommendations of the installation manufacturer and operating conditions. When working in difficult conditions (dust, temperature changes), the interval should be shortened.
What to do if the "Check Engine" indicator is on?
It is necessary to read the error code through the controller menu or diagnostic scanner. The light may indicate problems with oil pressure, engine temperature, or the electrical system. Operation with the indicator on is not recommended.
Can a refrigerator be used only as a heater?
Yes, most modern units have a heating mode (Heat), which uses engine heat or an electric heating element (if it is possible to connect to the network). This allows you to maintain a positive temperature of the cargo in winter.