Calculation formula for fixed values: Fixed value of current =1.5×3×(S1×L1+S2×L2)

L1 is the total length of overhead line at boundary switch load side. S1 is the empirical value of capacitive current of overhead line per km per phase. The recommended value is 0.02A/km.

L2 is the total length of cable at boundary switch load side. S2 is the empirical value of capacitive current of cable per km per phase. The recommended value is 1A/km.

Choose 1S when the neutral point is not earthed or earthed by arc suppression coil. Choose OS or lower when the neutral point is earthed by low resistance.

The calculation of fixed values for zero-sequence protection current only depends on the direct earth capacitance of cable or overhead line at switch load side. The table above is the results of approximate amount multiplied by safety factor. Users can calculate personally according to the actual condition of the line at switch load side. If there are both cable and overhead line at switch load side, add their direct earth capacitances together. The safety factor shall be chosen between 1.5~3 (It is recommended that a larger safety factor shall be chosen when the fixed value is relatively small, while a smaller one shall be chosen when the fixed value is relatively large.)

Enter Main Menu

When the system is idle, press “VIEW” to enter the main menu

After entering the main menu, press “ESC” to exit to idle status.

Switching of Menu Content

After entering the main menu, press “ENT” to select the content, press “” or “” to switch the content, and press “VIEW” to enter corresponding menu.

Press “ESC” to exit to idle status.

Modifying Fixed Value

After entering fixed value interface, press “ENT” to confirm the fixed value item and press “ENT” again to confirm the modification of fixed value. Press number buttons “0” to “9” to input the fixed value parameters. Press “” or “” to change the data position and press “SET” to save the fixed value (Press “ESC” to give up the modification and the fixed value after modification will not be saved).

After entering fixed value interface, press “” or “” to switch the fixed value interfaces.

After entering fixed value interface, press “ESC” to exit to the main menu.

Beijing TIANYIHONGDA Science & Technology Development Co., LTD is located in Lize Business Circle area, a prosperous business area in the center of Beijing City, China. is a high and advanced technology enterprise which is professionally engaged in research, production, sales and service of advanced smart monitoring technology products. We have great professional research team and techniques service team with rich working experience in the field of smart monitoring technology, cooperating with many famous Universities and Science Research Institutions on Smart Grid Automation, Smart Sensors and Wireless Communication and developing widespread market.

Our company has a great achievement in the development of Smart Grid, we by ourselves researched out the whole set of power distribution automation products such as DTU, FTU, RTU and so on. The central products and technology obtain national patents and certificate issued by relevant authoritative institution. The Fault Passage Indicators and Fault Location DTU systems has been stably running nearly 820,000 sets in the big city and middle city in domestic and overseas Market. accumulation of rich techniques and practical running experience on sites, these devices not only applied in the areas of national state grid, railway, petroleum, chemistry, coal, but also widespread used in the overseas countries such as India, Vietnam, Sri Lanka, Indonesian, Iran, Brazil, South Korea, South American and so on.

Meanwhile, the company is also successfully developing products to new monitoring fields, researched out Meteorological Monitoring Equipment, Environmental Monitoring Equipment and Video Monitoring Equipment and so on. All the products got the authoritative type test report and fully carry out and implement ISO9001 Quality Management System, these equipments have been successfully sold to domestic and overseas markets and approved by our clients.

Solar Power system with remote monitoring function is also successfully entering into market and get approval by the users. we have succefully finished many projects including commercial,residential applications for on-grid and off-grid applications such as 40KW substation, 60KW substation, residential ,countryside etc.

“ Sincerity is fundamental, clients is the first” & “strict quality control, earnest service supply” are our company’s management ideal, we sincerely invite all the cooperation partners working together to supply good qualities of products and service to domestic and overseas clients, devote ourselves to electrical smart grid development and monitoring technology development.