EP3480155A1

EP3480155A1 - Elevator system

Info

Publication number: EP3480155A1
Application number: EP17823852.3A
Authority: EP
Inventors: Shinsuke Inoue; Naoto Ohnuma; Tomoaki TERUNUMA; Naoki Takayama
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2016-07-04
Filing date: 2017-04-27
Publication date: 2019-05-08
Anticipated expiration: 2037-04-27
Also published as: EP3480155B1; CN109153538B; JP6578253B2; EP3480155A4; WO2018008244A1; JP2018002405A; KR20180134947A; CN109153538A

Abstract

An elevator system includes: a power supply switch that opens and closes a first power source route for connecting a power source and a power converter; a brake circuit that causes a brake to perform a release motion when receiving a supply of electric power from the power source, and causes the brake to perform a braking motion when the supply of the electric power from the power source is blocked; a first contact point that opens and closes a second power source route for connecting the power source and the brake circuit; a second contact point that is parallel-connected to the first contact point and opens and closes the second power source route; a first control circuit that controls opening and closing of the power supply switch; a second control circuit that controls opening and closing of the first contact point; a third control circuit that controls opening and closing of the second contact point; and a controller that controls operation of the power converter and manages the first control circuit, the second control circuit, and the third control circuit as control targets, wherein the controller: issues a command to the first control circuit, during a release operation of the brake, to perform an opening motion of the power supply switch and blocks a supply of the power source to the power converter; issues a command to the second control circuit to perform an opening motion of the first contact point and blocks the supply of the electric power to the brake circuit; and then issues a command to the third control circuit to perform a closing motion of the second contact point and supplies the electric power from the power source to the brake circuit by bypassing the first contact point.

Description

TECHNICAL FIELD

The present invention relates to an elevator system for performing a brake release operation.

BACKGROUND ART

A conventional elevator is designed to enable raising and lowering of a car, which is connected to a rope, by causing a power converter to rotate an electric motor and moving the rope upwards and downwards via a sheave which is coupled to the electric motor. If any part of a drive system such as this power converter, the electric motor, or an encoder connected to the electric motor fails, the elevator stops. When the stopped elevator car is positioned between floors and if there is any passenger(s) in the car, confinement occurs. Since the car does not move in a confined state, the safety of the passenger(s) is assured, but the passenger(s) will suffer discomfort.
A method for rescuing the passenger(s) confined due to such a failure of the drive system is generally performed by a maintenance operator. Particularly, when the weight within the car is not balanced with a balance weight, a brake is released manually and the car is moved to the closest floor by making use of the unbalance with the balance weight, thereby rescuing the passenger(s). Furthermore, other rescue methods include: a method for rescuing the passenger(s) by moving the car to a rescue port which is provided in a hoistway to rescue the passenger(s), but not to the closest floor; and a rescue method of making a normally-operating, adjacent elevator car come abreast of the stopped car and letting the passenger(s) in the stopped car move through an escape exit provided in the car to the normally-operating, adjacent elevator car.
Meanwhile, the above-described methods are performed after waiting for the maintenance operator to arrive, so that waiting time is required to rescue the passenger(s). As a method of solving this problem, there is disclosed an early rescue method by using a dedicated terminal that automatically releases the brake (see PTL 1).

CITATION LIST

PATENT LITERATURE

PTL 1: WO2010/058453

SUMMARY OF INVENTION

TECHNICAL PROBLEM

However, the technique disclosed in PTL 1 releases the brake by connecting to a brake control device for performing rescue work independently from a driving control device of the elevator and supplying electric power from the brake control device to the brake, thereby moving the car. Therefore, work to firstly connect to the brake control device is required in order to perform the rescue work, so that the time required for the rescue work increases. Furthermore, a common rescue work method is to move the car by having the maintenance operator directly operate the brake or turn a manual winding handle connected to a sheave of a hoist; however, regarding either of the above-mentioned work, the rescue work cannot be started unless the maintenance operator comes to the site of the elevator. So, the time required for the rescue work also increases.
It is an object of the present invention to provide an elevator system capable of stopping movements of a car during a release operation of a brake and then causing the brake to automatically perform a release motion.

SOLUTION TO PROBLEM

In order to solve the above-described problems, provided according to the present invention is an elevator system for an elevator equipped with a passenger car, a sheave around which a rope for connecting the passenger car and a balance weight is wound, a motor for applying a rotating force to the sheave, a power converter for controlling rotations of the motor, and a brake that performs a braking motion to apply a braking force to the sheave or a release motion to release the braking force on the sheave, wherein the elevator system includes: a power supply switch that opens and closes a first power source route for connecting a power source and the power converter; a brake circuit that causes the brake to perform the release motion when receiving a supply of electric power from the power source, and causes the brake to perform the braking motion when the supply of the electric power from the power source is blocked; a first contact point that opens and closes a second power source route for connecting the power source and the brake circuit; a second contact point that is parallel-connected to the first contact point and opens and closes the second power source route; a first control circuit that controls opening and closing of the power supply switch; a second control circuit that controls opening and closing of the first contact point; a third control circuit that controls opening and closing of the second contact point; and a controller that controls operation of the power converter and manages the first control circuit, the second control circuit, and the third control circuit as control targets, wherein the controller: issues a command to the first control circuit, during a release operation of the brake, to perform an opening motion of the power supply switch and blocks a supply from the power source to the power converter; issues a command to the second control circuit to perform an opening motion of the first contact point and blocks the supply of the electric power to the brake circuit; and then issues a command to the third control circuit to perform a closing motion of the second contact point and supplies the electric power from the power source to the brake circuit by bypassing the first contact point.

ADVANTAGEOUS EFFECTS OF INVENTION

After the movement of the car is stopped during the release operation of the brake, the brake can be caused to automatically perform the release motion according to the present invention.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 is an overall configuration diagram of an elevator system, which illustrates an embodiment of the present invention;
Fig. 2 is a configuration diagram of a power control circuit;
Fig. 3 is a block diagram for explaining the processing content of a controller; and
Fig. 4 is a flowchart for explaining the operation of the controller.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described below in detail with reference to the drawings.

[Embodiment]

Fig. 1 is an overall configuration diagram of an elevator system according to an embodiment of the present invention. Referring to Fig. 1, the elevator system is a system to which electric power is supplied from an external power source 1 via a breaker 2 and which is configured by including a contactor 3, a power converter 4, a controller 5, a power control circuit 6, a hoist 7, a car (passenger car) 8, a speed governor 9, a transformer 10, a first contact point 11, a second contact point 12, a power conversion circuit 13, a contactor 14, a brake coil 15, a brake 16, a rope 17, and so on; and primary sides of the contactor 3 and the transformer 10 are respectively connected to the breaker 2.
The breaker 2 is a switch provided in a control panel and is used to manually switch a supply of the external power source 1. The contactor 3 is a power supply switch for opening and closing a first power source route for connecting the external power source 1 and the power converter 4, is a switching device for supplying the electric power to the power converter 4, and is controlled by the controller 5 and the power control circuit 6. The power converter 4 is a power converting device for supplying the electric power to the hoist 7 and is composed of, for example, an inverter and the output electric power is controlled by a speed command from the controller 5. The controller 5 outputs a speed command for controlling the operation of the car 8 to the power converter 4 and also outputs a command for controlling the contactor 3, the first contact point 11, and the second contact point 12 to the power control circuit 6. The power control circuit 6 controls the contactor 3, the first contact point 11, and the second contact point 12 based on the command from the controller 5. The hoist 7 is a drive unit for causing movements to raise and lower the car 8 and includes a brake drum, a hoist motor coupled to one end of a rotating shaft of the brake drum, and a sheave coupled to the other end of the rotating shaft of the brake drum (none of the above-mentioned components is illustrated in the drawing); and a rope (main rope) 17 is wound around the sheave, one end side of the rope 17 is coupled to the car 8, and the other end side of the rope 17 is coupled to a balance weight (not illustrated in the drawing). Under this circumstance, the hoist motor is configured as a motor that applies a rotating force to the sheave; and the power converter 4 is configured as a power converter that controls rotations of the motor. The speed governor 9 is a safety device that detects a speed of the car 8 via a pulley 18 and a slave rope 19; and when the speed of the car 8 becomes a specified speed or higher, the speed governor 9 applies a brake to the car 8 by blocking an electric signal at a safety circuit belonging to the power control circuit 6 and blocking the power supply (the power source composed of the electric power distributed from the breaker 2 to the contractor 3 side) and the brake power source (the power source composed of the electric power distributed from the breaker 2 to the transformer 10 side).
The first contact point 11 is a contact point that controls supplying of the electric power to a brake circuit including the contactor 14 and the brake coil 15 (a first contact point that opens and closes a second power source route connecting the external power source 1 and the brake circuit). As the first contact point 11 is loaded, the electric power is supplied to the brake circuit and excitation of the brake coil 15 causes the brake 16 to be activated. Once the brake 16 is activated, the brake 16 moves away from the brake drum and the suppression of the car 8 is cancelled. Under this circumstance, the first contact point 11 is controlled by the power control circuit 6, including the safety circuit, and the controller 5. The second contact point 12 is a contact point that controls supplying of the electric power to the brake circuit independently from the first contact point 11 (the second contact point that is parallel-connected to the first contact point 11 and opens and closes the second power source route). The second contact point 12 is parallel-connected to the first contact point 11 and is controlled by the power control circuit 6, including the safety circuit, and the controller 5.
The power conversion circuit 13 is a bridge circuit composed of, for example, a diode and converts an AC voltage output from the transformer 10 into a DC voltage and applies a desired voltage to the brake circuit. The contactor 14 is a contactor in the brake circuit and is a device regarding which its loaded state is cancelled when performing braking by the brake 16. The contactor 14 is controlled by the power control circuit 6, including the safety circuit, and the controller 5. The brake coil 15 is a circuit element for controlling the brake 16 with an electromagnetic force. Normally, applying the electric power to the brake coil 15 causes the brake 16 to be pulled up and then the hoist 7 enters a rotatable state; and on the other hand, blocking the electric power to the brake coil 15 causes the brake 16 to be pulled down and then the hoist 7 enters a suppressed state. Under this circumstance, the brake 16 is designed to perform a braking motion to apply the braking force on the sheave or a release motion to release the braking force on the sheave. Furthermore, when the brake circuit including the contactor 14 and the brake coil 15 receives the supply of the electric power from the power source (the external power source 1), it causes the brake 16 to perform the release motion; and when the supply of the electric power from the power source is blocked, the brake circuit causes the brake 16 to perform the braking motion.
Fig. 2 is a configuration diagram of a power control circuit. Referring to Fig. 2, the power control circuit 6 is a circuit for controlling the contactor 3, the first contact point 11, and the second contact point 12 and is composed of a safety circuit 20, circuits 21, 23, 25, and buffer circuits 22, 24, 26; and the circuits 21, 23, 25 and the buffer circuits 22, 24, 26 are series-connected to the safety circuit 20 and are inserted into a feeder circuit connecting a direct current power source (+B) and the ground (GND).
The safety circuit 20 is composed of a plurality of contact points 20a, 20b, 20c, 20d belonging to a safety device group and the respective contact points are connected in series (the plurality of contact points which respond to activation or non-activation of the plurality of safety devices are series-connected to each other). The respective contact points 20a to 20d are composed of, for example, a final limit switch for detecting excessive movements of the car 8, a governor switch for detecting excessive speeds of the car 8, a switch for detecting opening and closing of doors for a landing area, and a switch for detecting opening and closing of doors for the car 8. Under this circumstance, when any one of the respective contact points 20a to 20d is turned OFF, the feeder circuit is released and the supply of the electric power to the circuits 21, 23, 25 and the buffer circuits 22, 24, 26 is blocked. For example, when the governor switch operates, the contact point of the governor switch is turned OFF, which causes the feeder circuit to be released, blocks the power supply to the circuits 21, 23, 25 for controlling the contactor 3, the first contact point 11, and the second contact point 12, and blocks the power supply to the power converter 4 and the hoist 7; and then the brake 16 is activated to apply the brake on the car 8.
When the supply of the electric power to the circuit 21 for controlling the contactor 3 is disrupted, the circuit 21 blocks (or turns off) the contactor 3 and blocks the supply of the electric power to the power converter 4; and when the electric power is supplied to the circuit 21, the circuit 21 causes the contactor 3 to enter a conduction state (or turns on the contactor 3) and supplies the electric power to the power converter 4. The buffer circuit 22 connected to the secondary side of the circuit 21 for controlling the contactor 3 is a circuit controlled by the controller 5. For example, when the control of the elevator car is conducted and if the safety device group is in a non-active state (where each contact point 20a to 20d is ON) as a result of loading of the buffer circuit 22 by the controller 5, the electric power is supplied to the circuit 21, the contactor 3 enters the conduction state, and the state where the electric power is supplied to the power converter 4 is established. Under this circumstance, the circuit 21 and the buffer circuit 22 are configured as a first control circuit for controlling opening and closing of the contactor (power supply switch) 3.
When the supply of the electric power to the circuit 23 for controlling the first contact point 11 is disrupted, the circuit 23 blocks the first contact point 11 and the contactor 14 and blocks the supply of the electric power to the brake coil 15; and when the electric power is supplied to the circuit 23, the circuit 23 causes the first contact point 11 and the contactor 14 to enter a conduction state and supplies the electric power to the brake coil 15. As the supply of the electric power to the brake coil 15 is disrupted, braking on the car 8 is performed by the brake 16; and when the electric power is supplied to the brake coil 15, the brake 16 is released and braking on the car 8 by the brake is cancelled. The buffer circuit 24 connected to the secondary side of the circuit 23 for controlling the first contact point 11 is a circuit controlled by the controller 5, basically performs the same motions as those of the buffer circuit 22 connected to the secondary side of the circuit 21 for controlling the contactor 3, and is used to release the brake 16 or to perform braking by the brake 16. For example, when the safety device group is in a non-active state (where each contact point 20a to 20d is ON) and the controller 5 loads the buffer circuit 24, the first contact point 11 and the contactor 14 enter the conduction state and the brake 16 is released; and when the controller 5 does not load the buffer circuit 24, the first contact point 11 and the contactor 14 enter a non-conduction state and braking by the brake 16 is performed. Under this circumstance, the circuit 23 and the buffer circuit 24 are configured as a second control circuit for controlling opening and closing of the first contact point 11.
The circuit 25 for controlling the second contact point 12 is a circuit parallel-connected to the circuit 23 for controlling the circuit 21, which controls the contactor 3, and the first contact point 11 and is used to bypass the first contact point 11. The buffer circuit 26 connected to the secondary side of the circuit 25 for controlling the second contact point 12 is a circuit controlled by the controller 5 and is a circuit to be loaded for bypassing the first contact point 11 in the state where the contactor 3 and the first contact point 11 are blocked. Specifically speaking, when the controller 5 loads the buffer circuit 26 in the state where the safety device group is not active (where each contact point 20a to 20d is ON), the second contact point 12 enters a conduction state and a brake power source is supplied to the brake circuit by bypassing the first contact point 11 even in the state where the contactor 3 and the first contact point 11 are blocked. Under this circumstance, the circuit 25 and the buffer circuit 26 are configured as a third control circuit for controlling opening and closing of the second contact point 12. Furthermore, the controller 5 controls the operation of the power converter 4 and manages the first control circuit, the second control circuit, and the third control circuit as control targets.
Next, how to use the circuit 25, which controls the second contact point 12, and the buffer circuit 26 will be explained. When a passenger rescue operation is to be carried out by the release operation of the brake 16, it is necessary to supply the electric power to the brake circuit. However, if the power converter 4 is in a state where the electric power is being supplied, there is a possibility that the motor of the hoist 7 may operate. So, as the controller 5 turns off the buffer circuits 22, 24 without loading the buffer circuits 22, 24, it blocks the circuit 21 for controlling the contactor 3 and the circuit 23 for controlling the first contact point 11 and firstly suppresses the car 8. Then, as the controller 5 loads the buffer circuit 26, it causes the circuit 25 for controlling the second contact point 12 to enter the conduction state and can supply the brake electric power to only the brake circuit via the second contact point 12, and it thereby becomes possible as the system to perform the rescue operation by releasing the brake 16.
Under this circumstance, the controller 5: issues a command to the first control circuit, during the release operation of the brake 16, to perform a motion to open the contactor (power supply switch) 3 and blocks the supply of the power source to the power converter 4; issues a command to the second control circuit to perform a motion to open the first contact point 11 and blocks the supply of the electric power to the brake circuit; and then issues a command to the third control circuit to perform a motion to close the second contact point 12 and supplies the electric power from the power source (the external power source 1) to the brake circuit by bypassing the first contact point 11. In this case, on condition that each of the safety devices is in a non-active state and each contact point belonging to the safety circuit 20 is in a closing motion state, the contactor (power supply switch) 3 and the first contact point 11 execute the opening motion and the second contact point 12 executes the closing motion.
Furthermore, the safety circuit 20 of the safety device group is connected to the primary side of the circuit 25 for controlling the second contact point 12. Accordingly, when any one of the safety devices is activated even during the release operation of the brake 16, the supply of the electric power to the circuit 25 for controlling the second contact point 12 is disrupted and the supply of the electric power to the brake circuit is also blocked, thereby making it possible to perform braking by the brake 16. In this case, on condition that any one of the safety devices is in an active state and any one of the contact points belonging to the safety circuit 20 enters an opening motion state, the second contact point 12 executes the opening motion.
Fig. 3 is a block diagram for explaining the processing content of the controller. Referring to Fig. 3, the controller 5 is a computer device equipped with information processing resources such as a CPU (Central Processing Unit), a memory, and an input/output interface. When a rescue operation start command is input, the CPU executes rescue operation start detection processing 30; when a safety device output is input, for example, when a signal indicating that each of the safety devices is activated is input, the CPU executes the safety device detection processing 31; when a feedback signal indicative of each motion state of the circuits 21, 23, 25 is input, the CPU executes processing 32 for detecting the circuits 21, 23, 25 and executes brake circuit loading processing 33 based on the respective processing results of the rescue operation start detection processing 30, the safety device detection processing 31, and the circuits 21, 23, 25 detection processing 32. Specifically speaking, the brake circuit loading processing 33 is executed based on feedback signals which indicate the state of the rescue operation start command indicative of the processing result of the rescue operation start detection processing 30, the active state of the safety device indicative of the processing result of the safety device detection processing 31, and each motion state of each circuit 21, 23, 25 indicative of the processing result of the circuits 21, 23, 25 detection processing 32. Incidentally, the rescue operation start command may be output from another software processing within the controller or, for example, may be manually input by the maintenance operator.
For example, when the rescue operation start command is input and the CPU executes the rescue operation start detection processing 30, the CPU executes, as a result of the processing result of the brake circuit loading processing 33, circuit 21 command creation processing 34 for creating a command to block the circuit 21 for controlling the contactor 3 and executes circuit 23 command creation processing 35 for creating a command to block the circuit 23 for controlling the first contact point 11. Then, after confirming, based on the feedback signal during the brake circuit loading processing 33, that the circuit 21 for controlling the contactor 3 and the circuit 23 for controlling the first contact point 11 are blocked, the CPU executes circuit 25 command creation processing 36 for creating a command to load the circuit 25 for controlling the second contact point 12. Furthermore, after confirming during the brake circuit loading processing 33 that the system is in a state capable of staring the rescue operation, the CPU executes rescue operation state output processing 37. Incidentally, during each of the circuit 21 command creation processing 34, the circuit 23 command creation processing 35, and the circuit 25 command creation processing 36, a command for controlling each circuit is output to each of the buffer circuits 22, 24, and 26 on the basis of an output signal which is input from the brake circuit loading processing 33. Furthermore, during the rescue operation state output processing 37, a signal indicative of the state capable of starting the rescue operation is output to, for example, another software block which performs the rescue operation, an LED attached to a substrate, and another control terminal connected to the controller 5.
Fig. 4 is a flowchart for explaining the operation of the controller. Referring to Fig. 4, the controller 5 firstly judges whether the rescue operation start command is ON or not (step S101). When the rescue operation start command is not ON, that is, when the rescue operation start command is not input, the controller 5 terminates the processing in this routine. On the other hand, when the rescue operation start command is ON, that is, when the rescue operation start command is input from the input device connected to the controller 5, the controller 5 judges whether the feedback signal of each of the circuits 21, 23, 25 is OFF or not (step S102). When the judgment result is NO in step S102, that is, when any one of the feedback signals is ON, the controller 5 outputs a command to turn off each circuit 21, 23, 25 again and terminates the processing (step S103); and when the judgment result is YES in step S102, that is, when any one of the feedback signals is OFF, the controller 5 outputs a command to turn off the circuit 21 and the circuit 23 and outputs a command to turn on the circuit 25 (step S104). Specifically speaking, the controller 5 executes the operation to bypass the first contact point 11, at which the electric power is blocked, by loading the second contact point 12.
Subsequently, the controller 5 judges whether or not the feedback signals of the circuits 21, 23 are OFF and the feedback signal of the circuit 25 is ON (step S105). When the judgment result is YES in step S105, that is, when the feedback signals are successfully detected correctly, the controller 5 outputs that the rescue operation can be started (step S106) and terminates the sequence of processing. When the judgment result is NO in step S105, that is, when the feedback signals cannot be detected correctly, the controller 5 determines a failure of any one of the circuits and suspends the processing (step S107) and terminates the sequence of processing.
According to this embodiment, after the car is stopped during the release operation of the brake, the brake can be caused to automatically perform the release motion. Specifically speaking, as the controller 5 blocks the electric power to the power converter 4, which supplies the electric power to the motor of the hoist 7, and supplies the electric power to only the brake 16, it can release the brake 16 and move the car 8. Furthermore, as a result of blocking the electric power to the power converter 4, unnecessary operations on the side of the motor for the hoist 7 can be eliminated and the safety during the release operation of the brake 16 can be enhanced. Furthermore, the primary side of the circuit 25 for controlling the second contact point 12 is connected to the safety circuit 20. So, when any one of the safety devices is activated during the release operation of the brake 16, emergency braking by the brake 16 can be performed by blocking the electric power supplied to the brake 16. Therefore, the safety during the release operation of the brake 16 can be enhanced.
Incidentally, the present invention is not limited to the aforementioned embodiment and includes various variations. For example, the aforementioned embodiment has been described in detail in order to explain the present invention in an easily comprehensible manner and is not necessarily limited to those having all the configurations explained above. Furthermore, regarding part of the configuration of an embodiment, another configuration can be added to, deleted from, or replaced with the above-mentioned part of the configuration.
Furthermore, part or all of the aforementioned configurations, functions, and so on may be realized by hardware by, for example, designing them in integrated circuits. Also, each of the aforementioned configurations, functions, and so on may be realized by software by processors interpreting and executing programs for realizing each of the functions. Information such as programs, tables, and files for realizing each of the functions may be recorded and retained in memories, storage devices such as hard disks and SSDs (Solid State Drives), or storage media such as IC cards, SD memory cards, and DVDs.

REFERENCE SIGNS LIST

3:: contactor
4:: power converter
5:: controller
6:: power control circuit
7:: hoist
8:: car
9:: speed governor
11:: first contact point
12:: second contact point
14:: contactor
15:: brake coil
16:: brake
20:: safety circuit
21, 23, 24:: circuits
22, 24, 26:: buffer circuits

Claims

An elevator system comprising a passenger car, a sheave around which a rope for connecting the passenger car and a balance weight is wound, a motor for applying a rotating force to the sheave, a power converter for controlling rotations of the motor, and a brake that performs a braking motion to apply a braking force to the sheave or a release motion to release the braking force on the sheave,
the elevator system comprising:
a power supply switch that opens and closes a first power source route for connecting a power source and the power converter;

a brake circuit that causes the brake to perform the release motion when receiving a supply of electric power from the power source, and causes the brake to perform the braking motion when the supply of the electric power from the power source is blocked;

a first contact point that opens and closes a second power source route for connecting the power source and the brake circuit;

a second contact point that is parallel-connected to the first contact point and opens and closes the second power source route;

a first control circuit that controls opening and closing of the power supply switch;

a second control circuit that controls opening and closing of the first contact point;

a third control circuit that controls opening and closing of the second contact point; and

a controller that controls operation of the power converter and manages the first control circuit, the second control circuit, and the third control circuit as control targets,

wherein the controller: issues a command to the first control circuit, during a release operation of the brake, to perform an opening motion of the power supply switch and blocks a supply of the power source to the power converter; issues a command to the second control circuit to perform an opening motion of the first contact point and blocks the supply of the electric power to the brake circuit; and then issues a command to the third control circuit to perform a closing motion of the second contact point and supplies the electric power from the power source to the brake circuit by bypassing the first contact point.
The elevator system according to claim 1,
further comprising a safety circuit in which a plurality of contact points for responding to activation or non-activation of a plurality of safety devices are series-connected to each other,
wherein the first control circuit, the second control circuit, and the third control circuit are inserted into a feeder circuit for connecting a direct current power source and
ground, are parallel-connected to each other, and are respectively series-connected to the safety circuit; and
wherein on condition that each of the safety devices is in a non-active state and each of the contact points belonging to the safety circuit is in a closing motion state, the power supply switch and the first contact point executes the opening motion and the second contact point executes the closing motion.
The elevator system according to claim 2,
wherein on condition that any one of the safety devices is in an active state and any one of the contact points belonging to the safety circuit enters an opening motion state, the second contact point executes the opening motion.