Shanghai Chenzhu Instrument CO., LTD.
Shanghai Chenzhu Instrument CO., LTD.

The Selection of DC Surge Protection Device

Dec 20 , 2021

1. How to choose a DC surge protection device?

Here are some things to keep in mind when you want to choose the right DC surge protection device in spd supplier.

(1) If stand-alone motors do not require high working conditions, and are simple to operate and control, and shutdowns have little impact on their production, ordinary protection devices can be used. Because ordinary protection devices have simple structures. DC surge protection device should be installed and connected on site and it is convenient to replace it. It is simple to operate, and has the characteristics of high cost performance.

(2) In response to poor working conditions and high requirements on reliability, especially for motors involved in automated production lines, mid-to-high-end, full-featured surge protection devices should be selected.

(3) For explosion-proof motors, eccentricity caused by bearing wear may lead to high temperature friction at the explosion-proof gap, resulting in explosion hazards. The product with wear status monitoring function should be selected. For special equipment such as large-capacity high-pressure submersible pumps, the function should also be selected due to difficult inspection and maintenance. Meanwhile it is necessary to monitor the temperature of the bearing, so as to avoid major economic losses caused by blast accidents.

(4) For surge protection devices used in places with explosion-proof requirements, the corresponding explosion-proof motor protection devices should be selected according to the specific requirements of the application site to avoid safety accidents.

2. The effect of lightning strikes on the two paths of DC surge protection devices

By far the biggest culprit for the power surges that damage solar panels are direct and indirect lightning strikes on the system. How to select spd for solar system becomes important.

(1) Direct lightning strike: The lightning discharge directly hits the components of the power system, and injects a large pulse current, but the probability of occurrence is absolutely low.

(2) Indirect lightning strike: The lightning discharge hits the ground around the equipment, generating a moderate current and voltage on the power line.

Therefore, photovoltaic spd will play an important role in protection. The dc power surge protector adopts advanced microcomputer technology and high-performance integrated chip. The whole machine has powerful functions, superior performance, high test accuracy, good linearity, high resolution, strong anti-interference ability, and reliable protection action. The display of voltage value and all kinds of faults is intuitive and clear, the stability is good, and the long-term work can be maintained without the need for maintenance.

3. The functional characteristics of DC surge protection device

(1) Protection function: In addition to the general protection function, there are functions of self-starting, communication start and close, and undercurrent, overvoltage, undervoltage, three-phase current imbalance, and other functions. Users can choose these functions freely.

(2) Setting function: The DC surge protection device has a setting button, a data button and a shift button. When the setting exceeds the range, it will remind the user to reset it to avoid misoperation. The basic type is set by dialing code or potentiometer.

(3) Alarm function: When the over-current indicating light of motor flashes and alarms, the greater the over-current multiple, the faster the flashing. Or use the external alarm connecting to the contact on motor protection device.

(4) Display function: After the motor protection device is powered on, press the setting button to display the current value, and press the data button to display the three-phase current value. After starting, the fault code is displayed and the corresponding fault indicator light is on, which is clear at a glance.