About us

Shenyang Longdy Electrical Equipment Co., Ltd. was established in 2003, is specialized in auxiliary switch research and development, manufacturing, set stroke switch, micro switch research and development and manufacturing, precision mold design and manufacturing, precision stamping parts, plastic parts processing in one of the high-tech research and development, production enterprises.

PURPOSETo comply with truth · To work with morality
VISIONBuild excellent enterprises, build a hundred billion business circle, and help the northeast economy
MISSIONTo create a rich and happy life for employees, at the same time, to contribute to the development of customers and society.
SENSE OF WORTHActively love life and work, to be rigorous, honest, grateful, humble and altruistic.
Mold workshop

Mold division has advanced processing equipment and testing equipment. There are more than 100 sets of processing equipment, such as vertical machining center, CNC lathes, high-precision wire cutting, EDM, engraving machine, milling machine, grinding machine, high-speed punching machine, etc. There are more than 30 sets of testing equipment, such as coordinate measuring instrument X fluorescence coating thickness tester, salt spray testing machine, simple beam impact testing machine, 1T plastic tensile testing machine, etc., which can ensure the production and processing cycle and quality control of molds and products...

read more >
Injection molding workshop

Shenyang Qingji Precision Molding Co., Ltd. is an independent business division of Longdy Electrical Appliances, established in 2010, specializing in the design and manufacturing of injection molds, die casting molds, rubber molds, injection products, die casting products, rubber products, mechanical processing, hardware products, stamping products production and sales. Plant construction area of 4500 square meters, more than 30 employees. Over the years, Qingji Molding has been focusing on the design, development and production of plastic mold sales, adhere to the purpose of quality, long-term for Volkswagen, Shenyang Broad, Switzerland ABB, Astak, Jinbo Johnson, South Korea Aige machinery and other well-known brand manufacturers to provide supporting molds and products...

read more >
Assembly shop

The company has product independent research and development, design, production capabilities. Has developed, produced and assembled 27 series of auxiliary switches (FK series, FH series, FH1 series, FR series, FR1 series, FC series, FB series, FA series, S100 series, CWA series, C2 series, LXB series, LZ series, LAA series, LFZ series, LFD series, LFE series, LFF series and LFG series, etc.), more than 400 specifications. All electrical products are produced according to the national low-voltage electrical standard GB/T14048.5-2008 (equivalent to IEC60947-5-1), and have passed the type test of the National Machinery Industry low-voltage explosion-proof electrical products quality supervision and testing center or Shanghai Electrical Equipment Testing Institute....

read more >
Electroplating workshop

Electroplating processing and manufacturing Department general description: the existing four production lines, respectively, alkaline galvanizing line, acid galvanizing line, rolling tin line, non-cyanide rolling silver line, 3 management personnel, 2 technical personnel, 27 production...

read more >
Machine shop

The machine workshop has 4 bench drills, 4 CNC cars, 1 machine walking machine, 2 general cars, can process all kinds of machine parts, professional skills are strong, can process scattered parts and batch parts....

read more >
Press shop

Our stamping workshop has 6 equipment, 80T one, 45T one, 25T three, 16T one, 6.3 tons one, can guarantee the quality and quantity of electronic connectors...

read more >
Business Partner
News Information
Addressing Hidden Hazards in Hydraulic Systems: Arc Formation in High-Voltage Auxiliary Switch Contacts—The Key Lies in the Scientific Selection of Arc-Extinguishing Contacts

In the operation of high-voltage power equipment, the stability of hydraulic systems directly affects the reliability of the entire power supply system. As core components of control and protection, the contact status of high-voltage auxiliary switches in hydraulic systems is of paramount importance. However, under long-term high-load, high-voltage operating conditions, arcing at the contacts of high-voltage auxiliary switches frequently occurs, not only threatening equipment safety but also potentially causing power outages. Faced with this challenging problem, accurately selecting arc-suppressing contacts has become the key breakthrough in addressing operational hazards in hydraulic mechanisms.

read more >
Redundant Signal Design for Micro Switches in Wind Turbine Hydraulic Systems: Building a “Signal Defense Line” for Safe Wind Power Operations

As the wind power industry undergoes large-scale and intelligent development, the stable operation of wind turbines directly impacts the continuity and safety of energy supply. As the core power execution unit of the turbine, the wind power hydraulic system bears the critical responsibility of precisely controlling key operations such as pitch, yaw, and braking. The design of redundant signals using microswitches in wind power hydraulic systems is emerging as a key technological breakthrough for mitigating the risk of signal failure in hydraulic systems and ensuring reliable turbine operation, thereby establishing a crucial defense line for the efficient operation and maintenance of wind farms.

read more >
How should the rated insulation voltage and rated impulse withstand voltage of high-voltage auxiliary switches be selected?

In the core control system of high-voltage electrical equipment, high-voltage auxiliary switches play a crucial role—they not only transmit control commands for the main circuit but also serve as the “first line of defense” for ensuring the safe operation of the equipment. The key indicators determining the robustness of this defense are the rated insulation voltage and the rated impulse withstand voltage. The selection of these two parameters directly affects whether high-voltage auxiliary switches can operate stably under complex operating conditions, thereby avoiding risks such as insulation breakdown and equipment failure. So, how exactly should the rated insulation voltage and rated impulse withstand voltage of high-voltage auxiliary switches be scientifically selected? This requires an in-depth analysis from three dimensions: technical fundamentals, application requirements, and standard specifications.

read more >