The constant temperature and humidity test chamber http:// refrigeration compressor, electric heater, cooling tower fan, cooling water pump, circulating water pump, fan coil centrifugal fan and ultrasonic humidifier are all controlled by relays. The control signal, the control signal of the single-chip microcomputer is converted by the five temperature sensor signals in the maintenance room, and then compared with the set value and processed. The composition and control logic of the constant temperature and humidity test chamber system are relatively complex. To ensure the safe operation of the system, the following protective measures are provided:
(1) Electrical safety. Protective components such as air switch, leakage protector, phase sequence protector, fuse and thermal overload protector are provided in the circuit to effectively protect against electrical faults such as leakage, overload, phase loss or reverse phase.
(2) Over temperature protection. If the water temperature is too low, the circulating water tank may freeze and freeze due to freezing. If the water temperature is too high, the evaporator coil may burst due to excessive refrigerant pressure. The leak test test pressure of the refrigeration system is 3 MPa, which corresponds to a saturation temperature of R22 of about 70 e. Therefore, a bimetal temperature switch is arranged in the circulating water tank of the constant temperature and humidity test chamber. When the water temperature is lower than 5 e or higher than 70 e, the contact is disconnected, the system is mechanically stopped, and the water temperature is returned to the setting. After the range is closed, the system is restored and the system is protected.
(3) Water shortage protection. A certain level of water must be maintained in the cooling water tank, circulating water tank and ultrasonic humidifier tank, otherwise serious failures may result. Therefore, the water tank (tank) is provided with a water-filling float valve and an overflow pipe, and a reed switch type water level switch is arranged at a low limit of the safe water level to protect the water. In order to avoid the malfunction of the protection switch caused by the instantaneous fluctuation of the water temperature and humidity test chamber http://water level, after setting the water level switch action, the system will stop the protective shutdown after 15 s delay, and an alarm signal will be issued, which cannot be automatically restored.
Electric hand drill is a drilling Tool powered by AC power or DC battery. It is a kind of hand-held electric tools.
Hand electric drill is the largest sales of power tools industry products, widely used in construction, decoration, furniture and other industries, used in the object on the opening or piercing objects, some industries are also known as electric hammer.
The main components of the hand electric drill: drill chuck, output shaft, gear, rotor, stator, housing, switch and cable.
Electric hand drill (pistol drill) - used for drilling metal materials, wood, plastic, etc. When equipped with a positive and negative switch and electronic speed regulating device, it can be used as an electric screwdriver. Some models are equipped with rechargeable batteries, which can work normally without external power supply for a certain period of time.
Electric Hand Drill,Customization Power Tools,Electric Tools Set,Power Tools Set
Behappy Crafts (suzhou)Co.,Ltd , https://www.behappyindustry.com