Bestact
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Market: Railway

Bestact products with built-in Bestact contacts meet the high specifications required by the railroad market for durability, vibration resistance, and high and rare frequency use.
Since 1979 to the present, our long-selling products have been used in a wide variety of equipment from rolling stock to railroad infrastructure facilities.

①Door-closing security device

The PSPD/PPMU series Bestact rod plunger type limit switches are used to detect the opening and closing of doors in the door-shutting safety device, and the RZDR series Bestact board type relay is used in the door-shutting relay panel that makes up the door-shutting circuit.
The RZDR series is responsible for control commands for operation indicator lights, solenoid valves for door opening/closing, and car-side indicator lights, etc.

 Solution


Conventional relays and switches have been subject to unstable door open/close operation due to contact failures and other problems that occur depending on the operating environment.

The unique contact structure of Bestact products, which have high contact reliability, reduces failures due to poor contact and contributes to the stable operation of trains.


 Adopted Products

② Car body tilting device

A reliable and precise control is required for a car body tilting device, which tilts the car body when it passes through a curve to maintain speed and provide a comfortable ride for passengers.

 Solution

With the development of the car body tilting device, a relay capable of controlling the opening and closing of the air suspension valve that tilts the car body at high frequency was required, and the RZDR series Bestact board type relay, which has been used in train equipment, was adopted.

The high reliability and durability of Bestact relays in high frequency operation contribute to the stable operation of trains.



 Adopted Product

③ Auxiliary contact for circuit breaker

Vestacle trot plunger type limit switches are used for the vacuum contactor auxiliary contacts of the motor control main converter, which are opened and closed each time the vehicle passes between substations.

 Solution


Conventional auxiliary contacts are prone to contact failures due to the mesh of dust, which can cause unstable operation checks of circuit breakers.

The PPMU series of Vestacle Trotor Plunger Type Limit Switches, whose unique contact structure is unaffected by dust and oxidation, has been adopted, contributing to stable operation of trains with its stable operation.



 Adopted Product

④ VVVF inverter controller

Bestact board type relays and Bestact plug-in type relays are used in the relay unit section of VVVF inverter controllers that convert the power supplied to the vehicle into a form suitable for each device.

 Solution


Conventional general relays have been subject to contact failures, etc., depending on the environment in which they are used, which can cause instability in the VVVF inverter control equipment, resulting in unstable control of the motor that powers the train. In addition, the VVVF inverter control system needed to be downsized and required to operate under high ambient temperatures.

Therefore, Bestact relays, which are less prone to contact failure, were adopted to ensure reliable operation even in high ambient temperatures, thereby contributing to the stable operation of trains. In addition, the Bestact relay, which has the same contact reliability as the mercury relay, has been adopted as a substitute for the mercury relay used in the past, which had to be replaced due to a decrease in its distribution.



 Adopted Products

⑤ General switchboard

Bestact board type relays are used in the general switchboard that transmits signals from the driver's cab and ATC equipment to each car, and play an important role in monitoring the movement of the entire train.

 Solution

Conventional relays have a tendency to have contact failures or other problems depending on the environment in which they are used, resulting in unstable transmission of vehicle information from the driver's cab.
In addition, the large size of the relay resulted in a large general switchboard, which occupied a large amount of space in the vehicle.

The RZDR series of vestibule-based relays, which are less prone to contact failures, have been adopted to reduce the size of the equipment and contribute to the stable operation of trains.



 Adopted Products

⑥ Automatic Train Control (ATC) equipment / Automatic Train Operation (ATO) equipment

ATC: These relays are used as interface relays for brake control of ATC devices that keep the vehicle speed below the speed limit.
ATO: These relays are used as interface relays for ATO devices, which are responsible for vehicle operation-related control, information linkage with each station, operation support, etc.

 Solution


Conventional relays are large in size, resulting in large ATC devices that occupy a large amount of space in the train car. In addition, contact failure of conventional relays sometimes interfered with train operation.

The RZDR/RIW series of vestibule-type relays has enabled the miniaturization of the equipment. The unique contact structure of the Bestact products, which are not affected by dust or oxidation and are less prone to contact failures, contributes to the stable operation of trains.


 Adopted Products

⑦ Main controller (mass controller)

Bestact proximity switches, Bestact micro-switches, and Bestact relays are used in the master controller, which controls the vehicle speed in the driver's cab.
The driver controls the speed by selecting a notch on the master controller according to the situation. The speed is set for each notch. The proximity switch detects the position of each notch, and the relay transmits the output signal of the notch.

 Solution


Conventional proximity switches, microswitches, and relays have been prone to contact failures under minute load opening and closing.

Therefore, Bestact products, which are less susceptible to dust and oxidation due to their unique contact structure and can operate stably even under minute loads, have been adopted to contribute to the stable operation of trains.


 Adopted Products

⑧ Automatic Train Stop System (ATS system ground terminal)

The ATS system that stops the train automatically stops the train when the train passes the ground equipment and the driver does not operate the system to stop the train in response to the alarm that the train is approaching the stop position.

 Solution


Conventional relays are susceptible to line vibration and external magnetic fields, requiring the installation of a control box for the relay at a distance from the ground terminal.

The RS Series of vestibule-type relays, which are resistant to vibration from the line and to external magnetic fields, can be built into the ground terminal within the line, eliminating the need for a control box.



 Adopted Product

⑨ Station platform door

Bestact relays are used in platform doors to prevent accidents involving falls on station platforms.
Upon arrival of a train, the platform doors open and close synchronized with the train doors.

 Solution


With the installation of platform doors at stations, relays were needed that could control the opening and closing of platform doors as reliably as the opening and closing of train doors.

The RB series Bestact relays, which have a proven track record in the railroad market, were adopted for use as platform door signal relays, taking advantage of their features of high reliability and high durability.



 Adopted Products

⑩ Station platform abnormality reporting device

Bestact proximity switches and Bestact board type relays are used inside the emergency stop buttons that communicate abnormal conditions on the platform to the train and the surrounding area.
Reliable operation is required even though they are used infrequently.

 Solution


Conventional proximity switches and relays sometimes fail to operate due to contact failure caused by dust entrapment or oxidation of the contact area.

Therefore, Bestact products with a unique contact structure that is unaffected by dust and oxidation have been adopted to help ensure passenger safety.


 Adopted Products