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The input reactor is used to restrain the sudden changes in the grid voltage and the current impact caused by overvoltage, smooth the peak voltage contained in the power supply voltage or the voltage defects caused by commutation of bridge rectifier circuit, thus effectively protecting VFD and improving power factor. It can not only prevent the interference from the power grid, but also reduce the pollution of the harmonic current generated by the rectifier unit to the power grid.

The oscilloscope probe is mainly used to guide the measured voltage signal from the measuring point into the oscilloscope for measurement. Probe is crucial to the accuracy and correctness of the measurement results, as it's the electronic component connecting the measured circuit and the input of the oscilloscope. The simplest probe is a wire that connects the measured circuit and the input of the oscilloscope, a complex probe consists of resistor-capacitor unit and active devices. A simple probe has no shielding measures, so it's susceptible to external electromagnetic interference. Meanwhile, larger equivalent capacitance in it would increase the load on the measured circuit, thus leading to distortion of the measured signal.

The gas solenoid valve is used for various ambient temperature, high temperature, negative pressure, low pressure and high pressure applications. The applicable fluid is air, nitrogen, oxygen, hydrogen, helium, carbon dioxide gas, argon gas, methane and other gas pipelines. Generally, solenoid valve for gas is mainly used in wide applications such as medical apparatus and instruments, rubber plastic machinery, clothing equipment, drying equipment and pharmacy industry, cooling industry, HVAC industry, electroplating coating industry, food and beverage industry and vacuum equipment industry.

ATO miniature circuit breaker is mainly used for AC 50Hz or 60Hz, voltage ratings 230/400V, 240/415V and 277/480V, and current ratings from 1A to 63A. The miniature circuit breaker is characterized with compact structure, reliable performance, strong breaking capacity and beautiful appearance. It can be applied for overloading and short-circuit protection of lighting, distribution lines and equipment of office buildings, houses and similar buildings. The mini circuit breaker is also used for not frequently on-off operations and conversions on the lines.

For some Microcontrollers, the resistance of sensor connected must be less than 10kΩ when carrying out the A/D transformation. For example, the resistance of Analog Devices's analog acceleration sensor is 32kΩ. It can’t work normally on the PIC and AVR control board. So it’s suggested to read the controller manual carefully before purchasing the sensor, so as to ensure that the sensor can work normally.

Frequent starting leads to excessively high temperature, overheating protection of the soft starter thereof operates (starting frequency of the soft starter shall be controlled within 6 times per hour, particularly in heavy load). Protective elements act at starting, which makes the contactor unable to by pass, the soft starter works for long time and thus causing the protection to act (check peripheral circuit). Heavy load and long starting time lead to overheating protection (reduce load as far as possible when starting). Parameters of soft starter are improperly set. Long starting time and low starting voltage (increase the starting voltage). Radiator fan of the soft starter can't work normally (replace a fan).

The load cell has a certain overload capacity, but it shall still be prevented from overloading in installation. It should be notified that even a short-term overload can still cause permanent damage to the sensor. During the installation, a pad with the same height of the sensor could be firstly used instead if necessary, then replace the pad with the sensor. In normal operation, the sensor should generally be equipped with mechanical structure for overload protection. If the sensor is fixed with screws, the screw should have a certain fastening torque and screwing thread depth. Generally, high strength screws should be used.

ATO Single phase to 3 phase converter has the function of filtering the grid disturbance and interference at the same time, which is a good performance of stabilized voltage and frequency power, to provide a more stable and pure power supply environment for the back end devices. Intelligent fan speed control system, low no-load loss. LCD display, high efficiency, easy installation. The output frequency 50Hz/60Hz can be set.

As everyone knows, direct starting of water pump would cause the water hammer effect. Namely when the water pump starts and stops, water impacts the pipe and cause a serious water hammer. When the power is off suddenly or the valve turns off quickly, a water impact wave generates due to inertia of pressure flow, which is like the knock of a hammer, so it’s called water hammer. Sometimes the force generated from water impact wave may be great and damage valve or pump, therefore, to avoid the negative effect of water hammer effect, the pump’s rotation speed should increase to the rated speed slowly when it’s started. Two methods are applicable, one is the variable frequency starting, another is the soft starting.

When selecting a output line reactor, its function shall be firstly determined, then the reactance ratio can be selected according to its functions, finally, the output line reactor capacity is selected according to the capacitor capacity (reactor capacity is equal to the capacitor capacity multiplied by reactance ratio). Selection of a reactor is complex, power grid quality and parameters, capacitor parameters shall be determined.

ATO sells VFD's power range from 1/2hp to 300hp, include single phase input and output VFDs from 1/2hp to 7.5hp, 110v/120v input VFDs from 1hp to 7.5hp, single phase input to three phase output VFDs from 1/2hp to 10hp, three phase input/output VFDs from 1hp to 300hp. All VFDs are manufacturer direct sale and quality guaranteed. Widely used in fans, pumps, lathes, cable machinery, printing and dyeing equipment, chemical machinery, plastic machinery, etc. The following are ATO variable frequency drive price lists for your reference. If you want more information, please go to ATO VFD products page.

Solid state relay (SSR) is a non-contact switch which drives a high-current load with a small control signal. The solid state relay consists of three parts, namely, the input circuit, the isolation (coupling) and the output circuit.Compared with the electromagnetic relays, solid state relays are characterized with high reliability, no contact, no spark, no noise, strong anti-interference ability, long lifetime, and fast switching speed. Now SSR are widely used in automation equipment, CNC machines, remote control system, instrumentation, medical equipment and so on.

A device that converts alternating current with constant voltage and frequency into alternating current with variable voltage or frequency is called "variable frequency drive". VFD has the functions of voltage regulation, frequency modulation, voltage stabilization, speed regulation etc. VFD is generally used to control 3 phase AC motor in variable speeds. Now the three phase 220v-240v motor can run on single phase 120v power supply. ATO offers you 110v/120v input, 220v/230v/240v output VFDs. It can not only realize single phase input & output, but also convert single phase to three phase.

Measurement method of a safety relay's DC resistance with a digital multiemter is similar to that with a pointer multimeter. According to the nominal DC resistance of safety relay, place the multimeter in an appropriate resistor and connect two test pens to the leading wire of the relay coil, then measure the resistance. Comparing the measurement result with the nominal resistance, if the error is within ±l0%, it's normal. If the resistance is obviously smaller, partial short-circuit fault exists in the coil; If the resistance is zero, the coil is short circuited; If the multiemter shows "1", the coil breaks.

Safety relay has special color, generally yellow. Current safety relay acts reliably and flexibly, it's mainly used to control the power supply circuit. When an emergency occurs, the circuit controlled by the safety relay is disconnected by pressing the emergency stop switch, thus ensuring safety.

Safety relay is the main component of electric locomotive control circuit and monitoring protection system. When the electrical components or connection wires in the main circuit or auxiliary circuit break as the electric locomotive is running, the safety relay of corresponding monitoring protection system can transfer the fault into electric signal. On one hand, the electric signal will be fed back to the opening coil of main breaker to trip the main breaker, thus cutting off general power supply of the electric locomotive to protect it. On the other hand, the electric signal will be fed back to signal device (including mechanical signal and electrical signal) and make it to display different fault conditions, thus guiding the electric locomotive conductor to deal with faults timely and correctly. In this respect, the safety relay doesn't directly control the main circuit or auxiliary circuit, but it's of great importance to the electric locomotive.

Measure coil resistance, resistance of a power relay coil can be measured with the R×10Ω band, thus judging whether the coil has open circuit. Measure actuation voltage and actuation current, with an adjustable stabilized voltage supply and ammeter, the power relay can be input with a voltage while the ammeter can be connected in series to monitor. Slowly increase the power supply. Voltage and record the actuation voltage and actuation current when the power relay is attracted. For accuracy, more operations can be repeated to get the average value. Measure release voltage and release current, connect wires as the test above. When the power relay is attracted, reduce the power supply voltage slowly and record the voltage and current as hearing the relay to release again. More operations can be repeated to get the average value.

Understanding the infrared thermometers’ working principle, technical specifications, working conditions, operation and maintenance is the basis for users to correctly select an infrared thermometer or use it. An infrared thermometer consists of optical system, photoelectric detector, signal amplifier, signal processing and display output. The optical system of infrared thermometer accumulates the target infrared energy in its field of view. And the size of field of view is determined by the optical components and location of the thermometer. The infrared energy is focused on the photoelectric detector and converted to corresponding electrical signal. The signal is corrected by the amplifier and signal processing circuit according to the algorithm inside the instrument and the target emissivity and then is converted to the temperature value of measured target.

Infrared temperature measurement technology plays an important role in production, product quality control and monitoring, on-line fault diagnosis and safety protection, as well as energy saving. Compared with the contact-type temperature measurement method, infrared temperature measurement has the advantages of fast response time, non-contact, safe use and long service life. Non-contact infrared thermometer involves three major series of portable, on-line and scanning thermometer, with various accessories and computer software. Moreover, each series has different types and specifications. Among these thermometers with various specifications, it is very important for users to choose a correct type of infrared thermometer.

Iron core of the AC contactor is usually laminated by silicon steel sheet, so as to reduce the eddy current and hysteresis loss generated by alternating magnetic field in iron core, avoid the iron core overheating. However, iron core in the DC contactor's coil would not generate eddy current and there is no heating problem in DC core, so the iron core can be made of a complete cast steel or cast iron. Coil of DC circuit has no inductance, so the coil has more turns, thus leading to large resistance and copper loss. In order to keep a good heat dissipation for the coil, the coil is generally made into a thin and cylindrical shape. Coil of AC contactor has less turns and small resistance, but the coil also gives heat, so the coil is generally made into a fat and short cylindrical shape. Meanwhile, a clearance is left to facilitate heat dissipation while avoiding the coils from being burned out. In order to eliminate vibration and noise generated by electromagnet, a short circuit ring is embedded on the surface of static iron core of the AC contactor, while the DC contactor doesn't need a short circuit ring.