High and low temperature test chamberThe electrical system is like the "central nervous system" that operates, and once a malfunction occurs, it will affect the normal progress of the experiment. In the face of such faults, it is necessary to follow a certain logical sequence to gradually troubleshoot. The following Hubei Gaotian test equipment will provide you with a detailed introduction to the inspection method.

1、 Power supply inspection

1. Investigation of power supply lines:Firstly, confirm whether the power plug of the test box is securely inserted into the socket, and check if the socket is powered on, which can be verified by connecting other electrical equipment. For the three-phase power supply test box, open the distribution box and check if the corresponding air switch trips. If the circuit trips, try to close it again, but before closing, check for any abnormal conditions such as short circuits. At the same time, use a multimeter to measure the voltage of the power supply line, ensuring that the voltage value is within the allowable fluctuation range of the rated voltage of the test box (generally ± 10%). If the voltage is too high or too low, it may cause faults in the electrical system of the test box.

2. Power cable inspection:Carefully inspect the power cables from the distribution box to the test box, and check for any signs of damage or aging on the outer skin. If the outer sheath of the cable is found to be damaged, it should be replaced in a timely manner to prevent leakage accidents from occurring. In addition, check if the cable connectors are loose. Loose connectors may cause poor contact, unstable voltage, or malfunction of electrical equipment. For loose connections, it is necessary to tighten them again and ensure good contact.

2、 Control circuit inspection

1. Controller inspection:The controller of the high and low temperature test chamber is the core of the entire electrical system, responsible for controlling and monitoring various parameters of the test chamber. Firstly, observe whether the display screen of the controller is displaying normally, and whether there are any garbled characters, black screens, or other phenomena. If there is no display on the screen, check if the power indicator light of the controller is on. If the indicator light does not light up, it may be a problem with the power input part of the controller. It is necessary to check whether the power cord is connected properly and whether the fuse is blown. If the fuse is blown, it is necessary to identify the cause and replace it with a fuse of the same specification. At the same time, check whether the buttons of the controller are sensitive and whether the parameters can be input normally. If the button fails, it may be due to damage to the button itself or internal circuit failure of the controller, and further investigation is needed.

2. Relay inspection:Relays play a role in signal conversion and amplification in control circuits. During the operation of the test chamber, listen for the sound of the relay closing and releasing. If the relay has no operating sound, use the voltage range of the multimeter to measure whether there is voltage at both ends of the relay coil. If there is voltage, it indicates that the relay coil is normal and there may be a problem with the relay contacts. The conductivity of the contacts can be measured using the resistance range of a multimeter. If the contacts are not connected, the relay needs to be replaced. If there is no voltage at both ends of the relay coil, it is necessary to check the circuit part of the control relay to see if there is any open circuit, short circuit or other component damage.

3. Contactor inspection:Contactors are mainly used to control the on/off of high-power equipment such as heating and cooling. Check the appearance of the contactor for signs of burning or smoking. If there is, it indicates that the contactor may have been damaged and needs to be replaced in a timely manner. During the operation of the test chamber, listen for any abnormal noise from the contactor. If there is noise, it may be due to poor iron core engagement or damaged short-circuit ring of the contactor. At the same time, use a multimeter to measure the conductivity of the main contacts of the contactor. If the contacts have poor contact or open circuit, the contactor needs to be replaced.

3、 Sensor inspection

1. Temperature sensor inspection:The temperature sensor is a key component for controlling the temperature of the test chamber. Common temperature sensors include thermocouples and thermistors. For thermocouples, use a multimeter to measure the thermoelectric potential at both ends, and determine whether the measured value matches the actual temperature based on the thermocouple's scale. If the thermoelectric potential is abnormal, check whether the thermocouple connection is firm and whether there is any disconnection. For a thermistor, use a multimeter to measure its resistance value, and based on the characteristic curve of the thermistor, determine whether the measured value corresponds to the actual temperature. If the resistance value is abnormal, check if there is any open or short circuit in the circuit of the thermal resistor. At the same time, check whether the installation position of the temperature sensor is correct and whether it is in good contact with the measured object. If installed improperly, it may result in inaccurate temperature measurements.

2. Humidity sensor inspection:The humidity sensor is used to monitor the humidity inside the test chamber. Check the appearance of the humidity sensor for moisture and contamination. If there are stains on the surface of the sensor, you can gently wipe it with a clean soft cloth. Measure the actual humidity inside the test chamber using a humidity tester and compare it with the value displayed by the humidity sensor. If there is a significant deviation between the two, it may be due to a malfunction in the humidity sensor and the sensor needs to be replaced. At the same time, check if the calibration parameters of the humidity sensor are correct. If the calibration parameters are incorrect, it can also cause inaccurate humidity display and require recalibration of the humidity sensor.

4、 Perform component inspection

1. Heating system inspection:Heating systems typically consist of heating tubes, solid-state relays, and other components. Firstly, check the appearance of the heating tube to see if there is any redness or breakage. If the heating tube turns red, it may be due to the surface temperature of the heating tube being too high. It is necessary to check the heat dissipation of the heating tube or whether the temperature control system is normal. If the heating tube breaks, it needs to be replaced. Measure the resistance value of the heating tube with a multimeter. Under normal circumstances, the resistance value of the heating tube should be within a certain range (refer to the specifications of the heating tube for details). If the resistance value is infinite, it indicates that the heating tube is open and needs to be replaced. At the same time, check the working status of the solid-state relay. During heating, the input terminal of the solid-state relay should have a control signal, and the output terminal should be conductive. If the solid-state relay has no output, it may be damaged and needs to be replaced.

2. Refrigeration system inspection:The refrigeration system is relatively complex, including components such as compressor, condenser, evaporator, solenoid valve, etc. Firstly, listen for the sound of the compressor running. If the compressor has no running sound, check if the power cord of the compressor is connected properly and if the fuse is blown. If the fuse is blown, the cause should be identified and replaced. At the same time, check if the overload protection device of the compressor is activated. If the overload protection device is activated, wait for it to reset or check if the compressor is overloaded. Check the heat dissipation of the condenser and evaporator. If the heat dissipation is poor, it will affect the cooling effect. For solenoid valves, check whether they can open and close normally by listening to the sound of the solenoid valve's action or measuring its resistance value with a multimeter.

By using the inspection methods of the above system, a comprehensive investigation can be conductedHigh and low temperature test chamberMalfunctions in the electrical system. During the inspection process, attention should be paid to safety to avoid accidents such as electric shock. If you are not familiar with the electrical system, it is recommended to conduct inspections and repairs under the guidance of professional personnel.