Products & Solutions

Place of Origin: China
Brand Name: Longsun
Model Number: LTZQ2
Minimum Order Quantity: 1 pc
Delivery Time: 15 working days
Payment Terms: L/C, T/T, Western Union, etc.



Control and Protection Switchgear


LTZK1 series control and protection switching appliances are new products in low-voltage electrical appliances. The abbreviation of “Device”, which conforms to the standard IEC60947-6-2 (1997) “Low-voltage switchgear and control equipment Part 6: Multifunctional electrical appliances Section 2: Control and protection switching appliances” (first edition in August 1992 ) and GB14048.9-1998 “Low-voltage switchgear and control equipment multifunctional electrical appliances (equipment) Part 2: Control and protection switching electrical appliances (equipment)” (equivalent to IEC60947-6-2). The codes and electrical symbols stipulated by IEC standards and national standards are shown in the figure below.

LTZK1 series control and protection switchgear implements integrated and internally coordinated control and protection functions on a single-structure product, which can replace circuit breakers (fuse), contactors, overload (or overcurrent, phase failure) protection relays, starters, isolators, and other traditional separation components, have the function of controlling operation by means of both long-distance automatic control and local manual control, have coordinated and coordinated time-current protection characteristics, and have control and protection cooperation, continuous operation after a short circuit, high breaking capacity, small arcing distance, long life, adjustable protection and setting current, convenient operation, various supporting accessory modules, etc., can realize the motor load and distribution load. control and protection.

The emergence of multi-functional electrical appliances has fundamentally solved various problems of unreasonable control and protection coordination caused by unreasonable selection of traditional discrete components (usually circuit breakers or fuses + contactors + overload relays), especially It overcomes the phenomenon of uncoordinated protection and control characteristics due to the combination of electrical products with different assessment standards, and greatly improves the operation reliability and continuous operation performance of the control and protection system.

The first generation of LTZK1 series control and protection switchgear is relatively large in size, and the protection adopts bimetallic strip technology. Although the second-generation product solved the problem of bulkiness, there was no major breakthrough in protection technology. As the application of microelectronics technology in the low-voltage electrical industry expands and deepens, the company takes the road of high-end product design based on the latest microelectronics technology, invests heavily in the development of products with international advanced level, and brings together discrete components. Advantages, complete functions, reliable performance, providing a basic component for the simplification and optimization of low-voltage power distribution and control systems.




Product Categories

●According to the working principle, it is divided into: electronic trip unit, intelligent trip unit

●Divided by operating frequency: frequent operation, infrequent operation

●According to the protection object, it is divided into motor protection, power distribution protection

●According to the wiring mode, it is divided into front panel, rear panel, plug-in type



Function and Use


LTZK1 adopts a modular single-product structure type, integrating the main functions of traditional circuit breakers (fuse), contactors, overload (or overcurrent, phase failure) protection relays, starters, isolators, etc., with remote automatic control It has the function of local manpower control, panel indication and electromechanical signal alarm function, overvoltage and undervoltage protection function, phase failure and phase loss protection function, and coordinated time-current protection characteristics (with an inverse time limit, definite time limit, and instantaneous Three-stage protection feature). Optional functional modules or accessories are required to realize the control and protection of various motor loads and power distribution loads.


LTZK1 is mainly used for making, carrying, and breaking normal conditions (including specified overload conditions) in power systems with AC 50Hz (60Hz), rated voltage up to 690V, rated current from 1A to 125A, and adjustable working current from 0.4A to 100A Under the current, and can make, carry and break the specified abnormal conditions (such as short circuit) under the current.



Applicable field

Because the LTZK1 series of products have control and protection function integration, modularization and miniaturization structure, a High level of protection against environmental pollution, High breaking short-circuit current capacity, Short arcing distance, Long battery life, It has a series of advantages such as complete protection functions, high continuous operation performance, and reliability, convenient installation, use, and maintenance, so it is especially suitable for the following systems:
●Power distribution and motor protection and control systems in metallurgy, coal mines, steel, petrochemicals, ports, ships, railways, and other fields;
●Illumination, power conversion, pump, fan, air conditioner, fire protection, lighting, and other electrical control and protection series in modern buildings;
●Motor control center (MMC), especially the intelligent electric control system or the power distribution control and protection system that requires rated operating breaking capacity Ics up to 80kA;
●Single motor control and protection system in factories or workshops;
●Remote control lighting system.



Product main features

Compared with the system composed of separate electrical appliances (see the table below)

●With the characteristics of self-coordination of control and protection

LTZK1The series of control and protection switch appliances integrate control and protection functions, Equivalent to a circuit breaker(fuse) +contactor+thermal relay+Auxiliary appliances. It solves the matching problem of protection and control characteristics between components that cannot be solved or are difficult to solve by separating components, and make the protection and control characteristics more perfect and reasonable(With inverse time, definite time, and instantaneous three-stage protection characteristics), as long as a single product can be correctly selected according to the load power or current, it can replace the various electrical appliances from the power supply line to the load end in the past, without derating; it greatly reduces the workload of designers.


●With incomparable operational reliability and continuous operation performance of the system

LTZK1After breaking the short-circuit current, it can be put into use without maintenance, That is, it has continuous operation performance after breaking and short-circuit faults: after the breaking and short-circuit current test, still have6000more than timesAC-44electrical life, This is difficult to achieve in a system composed of separate devices such as circuit breakers. LTZK1This feature greatly improves the reliability of the system and the continuous operation performance of the system. The operating short-circuit breaking capacityIcsfor80kAThe index belongs to the international leader and the highest domestic index of similar products.



Technical performance comparison table


Technical performance A system composed of separate electrical appliances LTZK1 switch electrical system
Breaking capacity 10~50kA 35~80kA
Mechanical life 5 to 10 million times 5 to 10 million times
Electrical life 100,000~150,000 times 1.2 to 1.5 million times
Setting current regulation Curve Straight line
Line Matching Consistency Difference Good
Current limiting capacity Low high
Self-cooperating protection features Without With
Continuous operation characteristics Without With



Compared with molded case circuit breakers
●It has the characteristics of high breaking capacity and small arcing distance
Under 380V rated operating conditions, the short-circuit breaking capacity Ics (O-CO-CO) of LTZK1 reaches 80kA (high breaking type), 50kA (standard type), and 35kA (economical type). The breaking time under the expected short-circuit current of 50kA is only 2-3ms, and the current-limiting coefficient reaches below 0.2, reaching the leading level of molded case circuit breakers and close to the current-limiting level of fuses, which greatly limits the dynamic and thermal effects of short-circuit current on the system Impact, the arcing distance of LTZK1 is less than 30mm.
●Compared with the protection system composed of molded case circuit breakers, it has the characteristic that the protection setting current can be adjusted
LTZK1 thermal release(inverse time limit )current magnetic tripping(definite time limit )The current can be adjusted on the panel. That is, in addition to the conventional thermal overload protection current can be set according to the load power(Ir1 The adjustment range is 0.4~1le), the overload protection setting current can also be adjusted on the panel(Distribution loadIr2The adjustment range is3-6Ir1). It overcomes the disadvantage that the short-circuit protection setting current of the molded case circuit breaker cannot be adjusted by the user after leaving the factory.makeLTZK1Even if the product is installed at the end of the line. When the short-circuit current is small, It also has a good short-circuit protection function.



Lost your password?


Input your email address for our latest catalog.


Enjoy this website? Please spread the word :)