What should I do if the thermal shock test chamber keeps heating up

The thermal shock test chamber is used to test the degree to which a material structure or composite material can withstand a continuous environment of high and low temperature in an instant. As a high-precision, high-efficiency environmental test equipment, the thermal shock test chamber is relatively cumbersome to troubleshoot and solve due to the complexity of its own system and process. The main faults and troubleshooting methods of the thermal shock test chamber:

1.Control interface display: three-phase power supply phase sequence error checking mode:

1. Is the part of the three-phase power supply phase sequence error fault displayed in the red indicator light not flashing state?2. Is the part of the three-phase power supply phase sequence error fault displayed in the flashing state of the red indicator light?Solution:

1. This situation usually occurs when the equipment is positioned or moved for the first time, and two of the three lines of the three-phase power supply can be reversed

If the temperature in the thermal shock test chamber has been heating up, it is certain that the heater in the inner tank of the test chamber is working all the time, and the power supply of the heater cannot be turned off through the normal signal supply, so that the heating tube can not stop heating rhythmically, when the temperature in the chamber rises to the warning value set by the thermal shock test chamber, it will produce an overtemperature alarm and power off or shutdown (to be determined by the way of production design) to protect the thermal shock test chamber, but there is also a situation, that is, the temperature has exceeded the alarm value, However, the buzzer is not working, and the temperature of the thermal shock test chamber is still rising, which is very dangerous, and it is very likely that all the products tested in the inner tank will be burned out and cause the thermal shock test chamber to catch fire.

If the user does not have basic experience in this area, the simplest and most direct way is to cut off the total power supply of the thermal shock test chamber and decisively notify the engineer to come to the door for maintenance; If there is a slight technical basis, at this time the multimeter should be used to measure whether the output signal of the instrument controller is normal, whether the solid-state relay is normal, whether the intermediate relay is normal, etc., and the abnormal components can be replaced, but it should be noted that when the instrument is abnormal, all the internal parameters should be set correctly after replacing the instrument, otherwise the thermal shock test chamber will not work normally.

When using a thermal shock test chamber, you need to pay attention to the following:

Check the equipment: Before operation, be sure to carefully check whether the various components of the thermal shock test chamber are in good condition, and repair them in time if there is any problem.

Control parameters: During the operation, the temperature, time, temperature rise rate and other parameters of the test must be controlled to ensure the accuracy of the test.

Sample management: When conducting experiments, it is necessary to manage the test samples well and carefully record the test data.

Safety precautions: The thermal shock test chamber needs to be connected to the power supply, so we must pay attention to safety precautions during operation, and cut off the power in time in case of emergency.

Maintenance: After using the thermal shock test chamber, the equipment needs to be cleaned, maintained and maintained to ensure the long-term use of the equipment.

Zhenghang's correct operation of the thermal shock test chamber is as follows:

1) The test sample should be placed in the test chamber according to the standard requirements, and the temperature in the test chamber (chamber) should be raised to the designated point, and the temperature should be kept for a certain time until the test sample reaches the temperature stability, whichever is the longest time.

2) After the end of the high temperature stage, the test sample will be converted to the low temperature test chamber (chamber) that has been adjusted to -55 within 5min, and keep it for 1h or until the test sample reaches temperature stability, whichever is longer.

3) After the end of the low temperature stage, the test sample will be converted to the high temperature test chamber (chamber) that has been adjusted to 70 within 5 minutes, and keep it for 1h or until the test sample reaches a stable temperature, whichever is the longest time.

4) Repeat the above experimental method to complete the three cycle cycles. Depending on the size of the sample and the size of the space, there may be a slight error in the time.

1. Dust sticking to the condenser will cause the high-voltage switch of the compressor to jump out and produce a false alarm, therefore, the dust attached to the condenser heat dissipation mesh can be sucked off with a vacuum cleaner every month, or a hard brush is used after start-up, or the dust is blown clean with a high-pressure nozzle;

2. The ground around the fuselage and at the bottom should be kept clean at all times to avoid a large amount of dust from being sucked into the unit and causing accidents or reducing the performance of the equipment;

3. When opening and closing the door or taking the sample from the test chamber, do not make it contact the sealing strip on the door;

4. Check the core of the test chamber - the refrigeration system once a year, check whether the copper pipe is leaking, and whether each joint and interface is responsible for leakage, if so, please notify the manufacturer;

5. The humidifier and water tank of the cold and thermal shock test chamber should be cleaned frequently to avoid scale and affect the emission of steam. Use a copper brush to scrub when washing, then clean with water;

6. The power distribution room should be cleaned and overhauled more than once a year, and the loose dust of the node will put the whole equipment in a dangerous working state, which will burn out the components, and cause fire, alarm and personal safety at worst;

7. Check the wet and dry bulb gauze frequently, and replace it in time when the gauze becomes hard or not clean, and it is recommended to replace it once every 3 months;

8. The water pipe of the waterway is a device that is easy to block and leak, and it is necessary to regularly check whether there is any leakage and water blockage, and eliminate or notify the manufacturer in time;

9. The water storage in the humidifier should be replaced once a month to ensure that the water quality is clean and the water flow is smooth;

10. When the test product time arrives, the product must be taken in the shutdown state and the staff must wear dry, electricity-proof and moisture-resistant gloves to pick up and place the product.

The impact test chamber is divided into two chambers of basket type thermal shock test chamber and three boxes of gas type thermal shock test chamber, which is suitable for electrical, electronic products and parts for cold resistance test, rapid temperature change or gradual change of the adaptability test chamber, especially suitable for electrical, electronic products environmental stress screening test. The thermal shock test chamber adopts the overall combination structure form, and the main body is composed of the high temperature test chamber located in the upper part and the low temperature test chamber in the lower part, the refrigeration unit cabinet at the rear and the electrical control cabinet (system) on the right side. The refrigeration unit is placed in an independent unit box to reduce the impact of vibration and noise on the test chamber during the operation of the refrigeration unit, and at the same time facilitate the installation and maintenance of the unit, and the electrical control panel is placed on the right side of the test chamber for easy operation.

Check and adjust the wet bulb water level of the thermal shock test chamber, almost every two or three tests need to be checked, and add water, remember to replace the test cloth of the hot and cold shock test chamber frequently, the test cloth should be replaced once every three months, the temperature sensor should be wiped with a cleaning cloth when replaced, and the new test cloth should be cleaned first. Regularly remove the dust from the condenser of the thermal shock test chamber, and the condenser should be maintained regularly and monthly. Pay attention to check the over-temperature protector of the thermal shock test chamber, if it runs unattended for a long time, please be sure to check the over-temperature protector before operation, and whether it is properly set up.

For the cleaning and maintenance of the inside and outside of the thermal shock test chamber, the internal impurities should be removed before operation, and the distribution room should be cleaned at least once a year, and the outside of the box should also be cleaned more than once a year. The humidifier of the thermal shock test chamber should be inspected and maintained, the water storage in the humidifier should be replaced once a month, and the humidification water tray should be cleaned once a month. The outer wall material of the cold and thermal shock test chamber is cold-rolled steel plate, and the surface is electrostatically sprayed; Insulation material: high-temperature resistant rigid polyurethane foam, ultra-fine glass wool; Single door, equipped with double silicone seal and sealing strip heating device, with self-limiting heating belt to prevent condensation and frost during the test; Slide up and down the stainless steel sample holder.

The pneumatic double-acting cylinder provides smooth opening and unwinding and uniform power, and the positioning device of the sample holder adopts a magnetic field-triggered travel switch. The cable test hole of the thermal shock test chamber is provided with a sliding cable threading pipe at the upper part of the sample holder and the top of the high temperature test chamber.

In order to ensure the correct use of the thermal shock test chamber, avoid damage caused by improper use of the instrument and products, and improve the validity, authenticity and accuracy of product test data. Equipment operators should pay attention to the daily inspection of instruments, and at the same time pay attention to the following operating specifications:

1.Thermal shock test chamber is in operation, please do not open the chamber door unless necessary.

2.Avoid turning off and then turning on the refrigeration unit in the three-point smile.

3.Do not connect the power supply used for the test sample to the power supply of the machine.

4.The lights should be turned off at all times except when necessary.

5.During the test, when the temperature of the cryogenic chamber exceeds 55, the chiller should not be turned on.

6.Circuit breakers, over-temperature protectors, please check regularly.

7.Before doing low temperatures, the studio should be wiped dry and dried for 1 hour at 60 hours.

8.It is forbidden to test **, flammable and highly corrosive substances.

9.The basket rails and racks should be lubricated regularly.

10.In any cross-section perpendicular to the prevailing wind direction, the sum of the test load cross-sectional areas shall not be greater than one-third of the working cross-section.

11.The sample to be tested should be fixed in the middle of the sample frame as much as possible, and should not be placed on one side at will, resulting in the tilting of the basket.

It can be caused by many aspects, and the first thing to do is to find out the cause before we can find a solution

1.If it is used for too long, three or five years, lack of hair maintenance, it will inevitably lead to the situation that the cold and thermal shock test chamber is not refrigerated.

2.First, observe the change in temperature, whether the temperature drops very slowly, or whether the temperature tends to rise after the temperature reaches a certain value. Another reason for the failure of the equipment may be due to the ambient temperature is not up to standard, the manufacturer recommends that the best temperature is 5-28 degrees (the average temperature in 24 hours is about 24 degrees), and the humidity is about 95%.

3.If the detection temperature deviation requires the sample to be placed in the workshop, when the sample volume is too large, or the way or position is inappropriate, the air convection is blocked. It can also lead to large temperature deviations.

The tightness of the box is not good. For example, the door leaks, which affects the temperature uniformity of the equipment studio.

4.Check the refrigeration system. First of all, check that the exhaust and suction pressures of the cryogenic compressors of the two groups of refrigeration units are lower than the normal values, and the suction pressure is in a state of evacuation, indicating that the refrigeration dose of the main refrigeration unit is insufficient, and the refrigerant needs to be increased.

If the temperature of the exhaust line and suction line of the compressor is not high, the temperature of the suction line is not low (not frosted), which also indicates the lack of refrigerant, and it is necessary to contact the manufacturer to fill the refrigerant.

If the cold and thermal shock test chamber does not cool down, it will affect the product inspection, so how to rule it out?

Check the refrigeration unit, the refrigeration system is the foundation of the cooling of the whole test chamber, if the refrigeration unit fails or the refrigerant leaks, it will not be cooled; (Find the manufacturer to solve the leakage and fill the refrigerant unit with refrigerant).

Check whether the low temperature range in the control system is set correctly and whether the program is correct; (The program setting can be assisted by the manufacturer's engineer).

The volume of the test product is too large, or there are too many test samples, resulting in the temperature in the test chamber not circulating, resulting in no cooling;

The cold and thermal shock test chamber has been used for a long time, whether it is regularly maintained and whether the maintenance is qualified; (You can find the manufacturer to come to the maintenance or assist in maintenance).

1.The condenser should be cleaned every 3 months: for the refrigeration system with air-cooled cooling, the condensing fan should be regularly overhauled, and the condenser should be decontaminated and dusted to ensure its good ventilation and heat exchange performance; For the refrigeration system with water-cooled cooling, in addition to ensuring that the inlet water pressure and inlet temperature are within the specified range, the corresponding flow rate must also be ensured, and the inside of the condenser must be cleaned and descaled regularly to obtain its continuous heat exchange performance.

2. If the cold and heat shock box is done at low temperature for a long time, when a cycle is completed, the temperature should be set to 110 degrees, and the door should be opened for two hours for defrosting. At the same time, after each test, the temperature should be set near the ambient temperature, work for about 30 minutes, and then cut off the power supply, and wipe the wall of the studio.

3.The evaporator should be cleaned regularly: due to the different cleanliness levels of the samples, under the action of forced air circulation, a lot of dust and other small particles will be condensed on the evaporator, which should be cleaned regularly.

4.Cleaning and balancing of circulating fan and condenser fan in low-temperature test chamber: Similar to cleaning evaporator, due to the different working environment of the test chamber, a lot of dust and other small particles will be condensed on the circulating fan blade and condenser fan, which should be cleaned regularly.

5.Thermal Shock Thermal Shock Cooling Shock Tank Waterway and humidifier cleaning: If the waterway is not smooth and the humidifier is fouled, it is easy to cause the humidifier to dry burn, which may damage the humidifier, so the waterway and humidifier must be cleaned regularly.

6.If the hot and cold shock box equipment needs to be relocated, it is best to carry out under the guidance of Ruikai instrument technicians, so as not to cause damage to the equipment, such as the customer relocates by himself, there must be a professional electrician to confirm that the circuit is correct before starting and running, otherwise it will burn out the relevant components of the equipment.

7.If the hot and cold shock box is not used for a long time, it should be powered on regularly every half month, and the power-on time should not be less than 1 hour, and whether the relevant parts of the equipment are operating normally should be detected.

It is provided by Ruikai Instrument, a professional manufacturer of thermal shock test chambers.