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Design of ARD3 motor protector with split LCD display

With the vigorous promotion and application of Electronic motor protectors, customers are more familiar with the application of this new electronic protection device, and at the same time put forward higher requirements for the use of products, especially parameter settings, fault inquiries, etc. Computer interaction.


With the vigorous promotion and application of electronic motor protectors, customers are more familiar with the application of this new electronic protection device, and at the same time put forward higher requirements for the use of products, especially parameter settings, fault inquiries, etc. Computer interaction.

1. The proposal of split LCD Display

The previous generation of ARD3 motor protector is divided into one-piece, split 72F, split 90F, all of which use LED (digital tube, LED is used to represent digital tube below) Display mode. In the field application, the LED display method has high brightness, and the effect can be seen at a glance even in places with poor light, with long service life and low product prices.

Compared with LCD (Liquid Crystal, LCD is used in the following to represent liquid crystal), the display brightness is not enough, and the display effect is better near the product. The effect is different at different viewing angles, and the brightness of the display screen is different when using a laptop computer. Same. LCD products are more expensive than LEDs.

However, LCD can display more data at a time than LED, especially when it is displayed in Chinese, its advantages in domestic use are more obvious. When customers perform parameter design and fault query on the previous generation of LED display ARD3, they usually need to use the manual (the LED display ARD3 has 53 menu items and 21 fault codes), which brings certain troubles to the actual application of the customer on-site. In order to make customer application more convenient, LCD display products came into being.

2. The advantages of split LCD display compared with previous generation LED display

2.1 Measurement parameters, fault record display

ARD3 can measure electrical parameters such as three-phase current, three-phase voltage, residual current, power, power factor, frequency, etc. The LED display must use the light-emitting Diodes on the panel to determine which electrical parameters are currently displayed, which is not intuitive and also There are a lot of information that cannot be displayed, such as: switch status, fault record, etc.

The LCD display solves the above problems very well. It adopts 128×64 dot matrix LCD, which can display 4 rows of data in one screen, with Chinese descriptions. There is no need to use light-emitting diodes on the panel to indicate specific parameters. Various menu items, switch status, fault records, operating parameters and other information have been displayed in Chinese on the display panel, which is convenient for customer parameters, fault query, and daily maintenance. The fault record data that can be displayed on the LCD includes: the current motor running time, the specific time of stopping, the cause of the fault, and various electrical parameters (three-phase current, three-phase voltage, residual current, etc.) during the stop.

2.2 Various protection function parameter settings

ARD3 has protection functions such as overload, phase failure, locked rotor, blocking, unbalance, underload, residual current, starting overtime, overvoltage, undervoltage, phase sequence, underpower and so on. In actual use, these protection functions may not all be turned on. When setting the protection parameters, LED products need to go through a binary-to-decimal conversion process. On-site operators are not very comfortable with this setting method.

The LCD display arranges the various protection functions in Chinese. When you need to set which protection function, you can directly find the corresponding item and enter the setting, which greatly facilitates the customer’s use.

2.3 Control aspects

The original LED display product has no start and stop operation buttons on the display panel, and customers can only complete the start and stop operations through the switch input signal.

LCD display products have their own start and stop buttons on the display panel. Customers can start and stop the motor through the LCD display panel without installing other buttons, thereby saving a lot of components and wiring work.

2.4 Other improvements

The split LCD display part and the main part of the ARD3 are connected by the aviation interface, and the connection is close; the RS485 level is used for the connection, which enhances the anti-interference and transmission distance of the product; summarizes the various starting methods, when the customer uses it on the spot You can change it by yourself; the panel adds stop, start, run, alarm, and trip indicator lights, which are closer to the actual needs of customers. A new generation of split LCD display ARD3 physical map shown in Figure 1.

Design of ARD3 motor protector with split LCD display
Figure 1 Split LCD display ARD3 physical image

3. Split LCD display ARD3 product features and technical indicators introduction

3.1 Product features

■ The display module adopts embedded installation, the module size is 90×70, the opening is 86×66 (unit mm), and the main body is installed on a guide rail.
■ The auxiliary power supply supports AC/DC 110/220V, AC 380V.
■ The measurement function is divided into basic measurement (current parameter) and optional measurement (voltage, power, phase sequence, residual current (grounding/leakage current)).
■ Comprehensive motor integration with overload, locked rotor, blockage, underload, phase failure, unbalance, residual current (ground/leakage), temperature, external fault, phase sequence, overvoltage, undervoltage, underpower, tE time, etc. Protective function.
■ 8 DI passive dry node inputs, and the signal power supply adopts the built-in DC24V power supply.
■ 4 DO outputs to meet various starting methods such as direct start, star-delta start, autotransformer start, soft start, etc. The remote master station can realize real-time remote control “start/stop” operation of the motor through the communication bus.
■ Anti-shake to ensure the uninterrupted operation of the motor. The restart function is used to restart the motor in batches when there is short-term undervoltage or loss of voltage.
■ It has a standard RS-485 communication interface and adopts the Modbus-RTU communication protocol to ensure the fast and reliable communication of the host computer.
■ It has a DC4-20mA analog output interface, which is directly connected to the DCS system, which can realize the monitoring of on-site equipment.
■ With system clock and 8 fault recording functions, the system clock records the current time (year, month, day, hour, minute, second); the fault recording function records the time when the motor fails, the total running time, the cause of the failure, and the failure Various parameter values ​​of the motor (such as three-phase current, three-phase voltage, residual current, power factor, heat capacity ratio, motor state, etc.) at the time.

3.2 Technical indicators

The technical indicators are shown in Table 1.

Design of ARD3 motor protector with split LCD display

3.3 Overload protection

Overload protection is one of the most important protections in use in the field, and this type of protection is turned on in almost all places where the motor is used. ARD3 uses the thermal model protection principle to simulate the actual heating of the motor for overload protection. ARD3 has 8 overload protection curves for customers to choose, among which curves 5, 10, and 30 are equivalent to the 10A, 10, and 30 trip level lines of the thermal relay respectively. The overload characteristic curve (K curve) is shown in Figure 2, and the overload protection comparison table is shown in Table 2.

Design of ARD3 motor protector with split LCD display
Figure 2 Overload characteristic curve

Table 2 Overload protection comparison table
Design of ARD3 motor protector with split LCD display

4 Conclusion

Through the introduction of this article, it can be seen that the split LCD display motor control and protection device is more in line with the requirements of users. The protection device not only reliably completes the measurement and protection functions, but also has good human-computer interaction capabilities, which reduces the use of customers. The difficulty is more conducive to the large-scale promotion of products in the market. The integrated control function and motor running status indication function (start, stop, alarm, fault) on the display panel can replace a part of buttons and indicator lights, saving costs for customers and reducing on-site wiring work.

The ARD3 motor protector adopts an advanced design scheme, integrating measurement, protection, control, and communication. The product performance is safe and reliable, and it can implement reliable and effective protection for the motor. In actual use, the ARD3 motor protector can completely replace traditional motor protection products such as thermal relays and temperature relays, replacing conventional components such as various pointer-type electricity meters, signal lights, and power transmitters, simplifying the motor control circuit and reducing cables in the cabinet. Connection and on-site construction volume.

The Links:   SKM300GB063D 1DI300Z-120