The heart of these systems is the elevator control panel. So, what exactly is an elevator control panel and what does it do? In this article, we will comprehensively discuss the topic of elevator control panels, explaining everything you need to know, from the history of elevator control panels to types and features of elevator control panels, their structure and working principle, selection, usage, and maintenance of elevator control panels.
What is an Elevator Control Panel?
The elevator control panel can be defined as the brain of the elevator system. It is a central unit where electronic and electromechanical components come together, controlling all movements, stops, door opening and closing operations, and safety functions of the elevator. Simply put, it is the control center that ensures the safe and orderly movement of the elevator between floors.
What Does an Elevator Control Panel Do?
The basic functions of an elevator control panel are as follows:
- Motion Control: Determines in which direction, at what speed, and when the elevator will move. When call buttons are pressed or floor selection is made, a signal is sent to the panel, and the panel activates the motor, allowing the cabin to reach the desired floor.
- Stop Control: Ensures that the elevator stops precisely at the desired floor. It continuously monitors the cabin's position through floor sensors and encoders and performs the stop at the correct floor.
- Door Control: Manages the synchronized opening and closing of elevator car and landing doors. It checks for any obstacles between the doors with safety sensors and ensures safe closing.
- Safety Functions: Controls various safety measures to ensure the safe operation of the elevator. It monitors systems such as overload sensors, emergency stop buttons, and safety circuits, and stops the elevator in case of any danger, ensuring safety.
- Fault Detection and Management: Detects malfunctions in the elevator system and informs users. Modern panels keep fault records, assisting maintenance teams in diagnosing faults.
- Energy Efficiency: Advanced control panels optimize motor speed and energy consumption according to the frequency of elevator use, saving energy.
History of Elevator Control Panels
The history of elevator control panels has progressed in parallel with the development of elevator technology. While early elevators were controlled by simple mechanical systems, control systems evolved with the advent of electric elevators.
- Early Periods: In the early examples of steam and hydraulic elevators, manual control systems were used. Operators controlled the movement of the elevator through mechanical levers and valves.
- Relay Logic Control Panels: With the widespread use of electric elevators, relay logic control panels began to be used. These panels controlled the basic functions of the elevator through electromechanical relays. Although relay systems offered more reliable and automatic control, they were complex and bulky in structure.
- Thyristor and Transistor Control Panels: With the development of semiconductor technology, thyristors and transistors began to be used in control panels. This made the panels more compact, increased control precision, and provided energy efficiency.
- Microprocessor-Based Control Panels: Today, elevator control panels are generally microprocessor-based. Microprocessors have significantly increased the control capabilities of panels, allowing for the implementation of more complex algorithms and the addition of advanced features. Microprocessor-based panels used with Variable Voltage Variable Frequency (VVVF) drives have maximized elevator performance and comfort.
Types and Features of Elevator Control Panels
Types of elevator control panels vary according to control technologies, intended uses, and elevator types. The main types and features of elevator control panels are:
- Single Speed Control Panels: Simple panels generally used in older and low-speed elevators. The elevator moves at a single speed, and the stopping precision is lower. They may have relay logic or simple electronic control systems.
- Two-Speed Control Panels: Offer more advanced control. The elevator moves at high speed during start-up and travel, and at low speed when approaching a stop. This provides a more comfortable ride and better stopping precision. They can use thyristor or transistor control systems.
- Variable Voltage Variable Frequency (VVVF) Control Panels: The most common panels used in today's modern elevators. Variable Voltage Variable Frequency (VVVF) inverters continuously adjust the motor's speed and torque, allowing the elevator to move much more smoothly and precisely. They offer advantages such as energy efficiency, comfort, stopping precision, and low noise levels. They are used with microprocessor-based control systems.
- Hydraulic Elevator Control Panels: Specially designed panels for hydraulic elevators. They control the hydraulic pump and valves to move the elevator. They are generally simpler in structure and may use relay logic or electronic control systems.
- Freight Elevator Control Panels: Powerful panels specially designed for freight elevators with high carrying capacity. They control motors and brake systems capable of safely carrying heavy loads. They generally use Variable Voltage Variable Frequency (VVVF) or two-speed control systems.
- Panoramic Elevator Control Panels: Specially designed panels for panoramic elevators where aesthetics are prioritized. They can also control transparent cabins and special lighting. They generally use Variable Voltage Variable Frequency (VVVF) control systems.
Structure of an Elevator Control Panel
The structure of an elevator control panel basically consists of electronic and electromechanical components. The main components inside the panel are:
- Control Board (Main Board): Considered the brain of the panel. It includes a microprocessor, memory, input-output units, and communication interfaces. It runs all elevator control algorithms and provides communication with other components.
- Drive (Inverter): A power electronics circuit that controls the motor's speed and torque. Found in Variable Voltage Variable Frequency (VVVF) panels and provides energy efficiency and comfortable movement.
- Power Supply: Provides the low voltage and current required for the electronic circuits in the panel. It usually produces voltages such as 24V DC and 5V DC.
- Relays and Contactors: Electromechanical switching elements. They are used to control high-power circuits such as the motor, brake, and door motor.
- Fuses and Circuit Breakers: Safety elements that protect circuits in case of overcurrent and short circuit.
- Terminals and Cable Connections: Terminals that provide electrical connections between components in the panel.
- Buttons and Indicators: Elements such as test buttons, fault indicators, and parameter setting knobs located on the panel.
- Car and Landing Call Boards: Electronic boards that detect signals from call buttons in the car and on the landings.
- Encoder and Sensor Input Boards: Boards that process position information from the motor encoder and floor sensors.
- Communication Boards: Boards that enable communication with other systems (building management system, remote monitoring system, etc.) through protocols such as serial communication (RS485, CANbus, etc.) or Ethernet.
Working Principle of an Elevator Control Panel
The working principle of an elevator control panel is based on controlling the elevator's movement in accordance with user requests (call buttons, floor selections) and feedback from the elevator system (position sensors, safety sensors). The basic working principle steps of an elevator control panel are as follows:
- Call or Floor Selection: The user makes an elevator call by pressing the call buttons on the landings or by using the floor buttons inside the car, or selects the floor they want to go to.
- Signal Detection: Signals from call buttons or floor buttons are detected by the input boards in the elevator control panel.
- Control Algorithm: The microprocessor on the control board uses pre-programmed control algorithms (e.g., picking up the nearest call, direction optimization) to determine in which direction to move and which floor to go to.
- Motor Control: The control board sends a signal to the drive (inverter) to activate the motor. In Variable Voltage Variable Frequency (VVVF) panels, the drive continuously adjusts the motor's speed and torque, providing smooth start-up, acceleration, deceleration, and stopping.
- Position Tracking: The motor encoder and floor sensors continuously track the cabin's position and send this information back to the control board.
- Stop Control: Using position information, the control board detects that the cabin is approaching the desired floor and sends deceleration and stop commands to the drive. The cabin stops precisely at the floor.
- Door Control: After stopping is complete, the control board sends signals to the door motors to open the car and landing doors. The door opening time can be adjusted.
- Safety Inspection: Continuously monitors signals from safety sensors. In case of overload, obstacle between doors, safety circuit fault, etc., it stops the elevator and activates safety measures.
- Fault Management: When a fault is detected in the system, the control board records the fault and informs users (usually via the indicator panel or remote monitoring system).
Elevator Control Panel Selection
Elevator control panel selection depends on many factors such as elevator type, intended use, building characteristics, and performance expectations. Some important points to consider for correct elevator control panel selection are:
- Elevator Type: Different control panel solutions may be required for different elevator types such as hydraulic elevators, rope elevators, freight elevators, panoramic elevators. A panel suitable for the elevator type should be selected.
- Speed and Performance Requirements: Elevator speed, stopping precision, start-up and stopping comfort performance expectations affect panel selection. Variable Voltage Variable Frequency (VVVF) panels should be preferred for applications requiring high performance.
- Energy Efficiency: If energy saving is an important factor, Variable Voltage Variable Frequency (VVVF) panels offer a more efficient solution.
- Safety Features: The safety functions of the panel (overload protection, emergency stop, door safety sensors, etc.) should be adequate. Panels compliant with safety standards should be preferred.
- Ease of Use and Fault Detection: It is important that the panel has a user-friendly interface, parameter settings are easy to make, and it offers quick diagnosis in case of faults.
- Building Characteristics: Building height, number of floors, traffic density, etc. factors may affect panel selection. More advanced control algorithms may be needed for high-rise buildings and high-traffic structures.
- Cost: Panel cost is also an important factor in the selection. However, instead of focusing solely on cost, factors such as performance, safety, and energy efficiency should also be considered.
- Compliance with Standards: Compliance of the selected panel with relevant elevator standards (e.g., EN 81-20/50) is a legal requirement and is important for safety.
Usage of Elevator Control Panels and Rules to be Followed
Usage of elevator control panels is usually done by expert personnel (elevator technicians, maintenance teams). Direct user intervention with the panel is generally not involved. However, there are some rules that users must also follow for the safe and efficient operation of the elevator:
- Avoid Unauthorized Intervention: Unauthorized intervention with the elevator control panel is dangerous and strictly prohibited. High voltage and complex circuits inside the panel can cause serious injury or system malfunctions.
- Know Emergency Procedures: It is important to be informed about what to do in an emergency (being trapped in the elevator, malfunction, etc.). The location and use of the emergency stop button should be known.
- Avoid Overloading: Loading should not be done in a way that exceeds the elevator's carrying capacity. Although overload sensors stop the elevator, continuous overloading can damage the system.
- Do Not Force Doors: Elevator doors open and close automatically. Forcing the doors or trying to keep them open can damage the mechanism and create safety risks.
- Do Not Use in Case of Fire: Elevators are not safe in case of fire. Fire escapes should be used.
- Do Not Neglect Maintenance and Inspections: Regular maintenance and inspections of elevators are vital to ensure their safe and trouble-free operation. The maintenance schedule should be followed, and regular inspections should be carried out by authorized services.
Elevator Control Panel Maintenance
Elevator control panel maintenance is critical for the overall safety and performance of the elevator system. Regular elevator control panel maintenance can prevent malfunctions, extend system life, and maintain energy efficiency. Elevator control panel maintenance usually includes the following steps:
- Visual Inspection: Visual inspection of the exterior and interior of the panel. The condition of cable connections, terminals, fuses, and other components is checked. Dust, moisture, and corrosion signs are investigated.
- Electrical Measurements: Voltage, current, and resistance values in the panel are measured to check whether the circuits are working properly. Insulation tests are performed to determine leakage current risks.
- Component Tests: Functional tests of relays, contactors, drives, control board, and other electronic components are performed. Faulty or worn components are identified and replaced.
- Parameter Control and Adjustment: The parameter settings of the panel (speed, acceleration, stopping precision, door opening time, etc.) are checked and readjusted if necessary.
- Software Update: In modern microprocessor-based panels, system performance and safety can be improved by performing software updates.
- Cleaning: The inside and outside of the panel are cleaned of dust. Air ducts and fans are cleaned to increase the efficiency of the cooling system.
- Function Tests: After maintenance, all functions of the elevator (call reception, floor stop, door opening-closing, safety systems, etc.) are tested to confirm that the system is working correctly.
Elevator control panel maintenance should be performed periodically by authorized and expert elevator services. Maintenance frequency is determined according to the elevator's usage intensity, age, and type.
In conclusion, the elevator control panel, as the heart and brain of modern elevator systems, is of vital importance for safe, comfortable, and efficient elevator operation. The history of elevator control panels has continuously evolved in parallel with technological development, and today, microprocessor-based, Variable Voltage Variable Frequency (VVVF) panels offer the highest level of control and performance. Types and features of elevator control panels are offered in a wide range according to different needs and elevator types. While the structure of the elevator control panel consists of complex electronic and electromechanical components, the working principle is based on precisely managing elevator movement in accordance with user requests and system feedback. Correct elevator control panel selection is of critical importance in terms of elevator performance, safety, and energy efficiency. Usage of elevator control panels and rules to be followed are important for both expert personnel and users. Regular elevator control panel maintenance, on the other hand, guarantees the long-lasting, safe, and trouble-free operation of the system.