Industry: Steel Plant

Bestact products with built-in Bestact contacts meet the high requirements for stable operation unaffected by the high temperature, high humidity, and dusty environment of the steel market, as well as for long life.
Since 1981, our products have been used in various position control and operation panels for each process from bringing raw materials from ports to steel making, contributing to stable plant operation.
In addition, our electromagnetic contactors (HU series) and limit switches (PSKU series), which do not incorporate Bestact contacts, are also long-selling products that are used in a wide range of applications in the steel market, thanks to their robust construction and abundant lineup to suit the operating environment.

① Crane winding upper limit position detection

This is employed as a limit switch for detecting the limit position of crane wire hoisting. It is mounted on the crane hoisting machine to prevent over-winding.

 Solution

The PSKU series limit switches for crane over-winding protection are robustly built and have high mechanical durability and long life, so they can be used maintenance-free for a long period of time even in high temperature and high humidity crane installation environments.

Attached to the take-up actuator by an operating rope, the limit switch detects the upper limit of take-up to prevent over-winding of the wire.
Since the upper limit position is detected mechanically, it is possible to determine the operating state (ON/OFF) by moving the lever up or down.



 Adopted Product

※The PSKU series can be selected according to the ambient environment, including high/low temperature, anti-corrosion, and low current (built-in Bestact) types.

② Mid/last position detection of crane traversing travel

Bestact magnetic proximity switches are mounted on the crane rails to detect the intermediate positions of traversing and traveling for deceleration, and Bestact limit switches are employed to detect the movable final positions of traversing and traveling.

 Solution


The Bestact magnetic proximity switch PSMS series, used for intermediate position detection, can be used in harsh environments such as dust and water (IP67 equivalent), has high contact reliability even with small currents, and contributes to stable equipment operation with its long life even with high frequency use.

The PSKU(R25) series of Bestact limit switches used for final position detection are of the lever type with rollers and have Bestact contacts built in. This type of switch can be used maintenance-free for a long period of time.



 Adopted Products

※The PSKU series can be selected according to the ambient environment, including high/low temperature, anti-corrosion, and low current (built-in Bestact) types.

③ Motor control of large cranes

It is employed to control large motors that power large cranes and other machine rooms.

 Solution


The HU series of clapper type low-voltage electromagnetic contactors, which are resistant to salt damage and have a long life, are used for motor control of large cranes in harbors and other locations.

The arc-quenching mechanism quickly extinguishes arcing by means of magnetism, resulting in high interrupting performance and excellent electrical longevity. The HU series also has high mechanical durability and can be used for a long period of time even with high frequency of use.



 Adopted Product

④ Conveyor emergency stop device

These switches are used as emergency stop switches for workers in the event of a conveyor malfunction. Several limit switches connected by wires are placed in parallel with the conveyor that carries raw materials.

 Solution

The PIKU series pull-wire switch type limit switches are installed in parallel with the conveyor by passing an emergency stop wire rope through the actuator. The limit switches are durable and long-lasting, even in environments where dust from the material flowing on the conveyor is blown around, and they are used as limit switches that can be used maintenance-free for a long period of time.

The structure is resistant to contact failure, so stable operation can be expected even in the rare use of emergency stop. An extensive lineup of lever shapes (single/double pull) and lever mechanisms (automatic/non-automatic return type) can be selected to suit the application.



 Adopted Product

※The PIKU series can be selected according to the ambient environment, including high/low temperature, anti-corrosion, and low current (built-in Bestact) types.

⑤ Conveyor belt unbalance detection

This switch is used to detect unevenness of the conveyor belt. They are installed on the left and right side in parallel with the conveyor that carries raw materials.

 Solution

The PSKU series limit switches are used to protect the belt against unevenness. When the conveyor belt becomes uneven or begins to meander due to a collapse of the load, the belt strikes the limit switch lever to detect an unevenness error. The robust construction of these limit switches provides high durability and a long service life, even in environments where dust from raw materials flowing on the conveyor may fly about, making them maintenance-free for a long period of time.

The P□KU-C□A type outputs an alarm or emergency stop signal depending on the degree of belt leaning, and horizontal and vertical mounting types are available to suit a wide variety of conveyor types.



 Adopted Product

※The PSKU series can be selected according to the ambient environment, including high/low temperature, anti-corrosion, and low current (built-in Bestact) types.

⑥ Intermediate / final position detection for each conveyor in the coke oven

Bestact magnetic proximity switches are used for intermediate position detection of various equipment such as charging cars, extruders, guide cars, and fire extinguishing cars that carry materials in coke oven plants, and limit switches are used for final position detection.

 Solution


The PSMS series Bestact magnetic proximity switches used for intermediate position detection and the PIKU series fork lever with roller type limit switches used for final position detection provide reliable position detection even in high temperature environments.

They are used for position detection of conveying equipment in each process of material loading, burning, and stacking in the adverse environment of coke ovens, contributing to the smooth operation of each process in coordination with each other.



 Adopted Products

※The PIKU series can be selected according to the ambient environment, including high/low temperature, anti-corrosion, and low current (built-in Bestact) types.

⑦ Position detection of slab cutting

It is employed as a Bestact magnetic proximity switch to control the moving position of a gas cutter that cuts slabs.

 Solution


The Bestact PSMS-RV series magnetic proximity switches have a protective structure equivalent to IP67 and can reliably detect the position where the gas cutter stops moving even in high temperature, dust, and gas environments.



 Adopted Products

⑧ Detection of clamp open/close limit of hot rolling mill

It is used as a position detection switch to detect the open/close limit of a clamp that extends a formed slab over 1000°C through a rolling machine at a speed of 80 km/h.

 Solution


The Bestact PSMS series magnetic proximity switches have a protective structure equivalent to IP67 and provide stable detection of clamp open/close limits even in adverse environments subjected to heat from the slab, large amounts of cooling water, and lubricating oil.
Furthermore, the long life and the fact that no power supply is required contributes not only to stable operation but also to reduced maintenance costs.



 Adopted Products

⑨ Cold rolling roller position / coil take-up detection

It is used as a detection switch for roller position and coil take-up in cold rolling mills to further increase plate thickness and make the surface beautiful and uniform.

 Solution


The Bestact PSMS-RV series magnetic proximity switches are used to accurately detect roller position adjustment and coil winding volume in cold rolling, where thickness control is strictly required.
The PSMS-RV series has a long service life even in adverse environments and is designed to prevent contact failure, making it a proximity switch that can be used maintenance-free for a long period of time.



 Adopted Products

⑩ Coil infeed plate position detection on galvanizing line

It is used as a position detection switch for the auxiliary plate that feeds the coil in the galvanizing line to prevent surface rusting and corrosion.

 Solution


The Bestact PSMS-RV series magnetic proximity switches have a protective structure equivalent to IP67 and can be used in adverse environments where hydrochloric acid vapor used in pickling during the plating process and oxidized iron powder are scattered in the surrounding environment.

The long-life and contact failure-resistant structure makes it an active proximity switch that can be used maintenance-free for a long period of time.



 Adopted Products

⑪ Stop position/travel section detection for carts and pallets

It is employed as a switch for detecting the stop position and travel section of a cart or conveyor pallet.
It detects the stop position of a cart and opens the hopper gate to replenish materials, and detects the traveling section of the cart and controls the speed of the cart for each section.

 Solution


The Bestact PSMO series magnetic proximity switches are used for detecting the stopping position of bogies and accurately detect the stopping position even under adverse conditions such as high temperatures and dust.
The Bestact PSMM series magnetic proximity switches are used for section position detection, and control the section speed of bogies as a self-maintaining switch that can maintain the switch in the ON or OFF state without the need for a power supply.

Both of these switches have a protective structure equivalent to IP67, are resistant to use in adverse environments, and have a long service life. Furthermore, since they do not require a power supply, maintenance costs are reduced and peripheral power circuits are reduced.



 Adopted Products

⑫ Operation switches for various equipment

These switches are used as operation switches for various operation panels in factories in adverse environments, and handle operation/stop/unwind of conveyors, etc.

 Solution


Bestact contacts built into the contact section of Bestact operation switches are used for operation command outputs in various equipment because they have a long electrical life even in power circuits with inductive loads (DC110-0.3A, L/R=40ms) and operate reliably even at minute currents (DC24V-1mA).

In addition, a wide variety of products can be manufactured according to customer-specified contact configurations and operation patterns.
Furthermore, the PLWG series of Bestact operation switches have a protective structure equivalent to IP56 and can be used in harsh environments such as those exposed to water and dust.



 Adopted Products