Mechanical Services Switchboards: Components and Functions Explained
Mechanical services switchboards are an essential component of any building's mechanical systems. They are responsible for managing the electrical power distribution and control for HVAC (heating, ventilation, and air conditioning) equipment, as well as other building services, such as lifts, escalators, and lighting. In this article, we will explore the different form factors of mechanical services switchboards and the components that make them work.
Form Factor
Form 1, 2, 3, and 4 are different types of switchboards used in the electrical distribution system of buildings and other facilities. The main difference between them lies in their design and the level of protection they provide.
Form 1 switchboards are typically used for low voltage control applications, and they feature a single enclosure with a separate door for the power and control sections. The power section typically includes circuit breakers or fused switches for individual circuits, while the control section contains relays, timers, and other control devices.
Form 2 switchboards are similar to Form 1 switchboards, but they have separate enclosures for the power and control sections. The power section usually includes a main circuit breaker or switch, while the control section contains a range of control devices.
Form 3 switchboards are more complex than Form 1 and 2 switchboards and are used for larger installations. They feature a single, larger enclosure with a separate section for the busbar and the individual circuit breakers or fused switches. The control section is often located in a separate enclosure.
Form 4 switchboards are the most complex and sophisticated type of switchboard, and they are used for very large electrical installations. They feature a separate enclosure for the busbar, the incoming and outgoing cables, and the circuit breakers. The control section is usually located in a separate enclosure.
The main differences between Form 1, 2, 3, and 4 switchboards are the number of enclosures, the separation of power and control sections, and the level of protection they provide for the electrical distribution system. The choice of switchboard type depends on the specific requirements of the installation, including the size of the facility, the type of equipment used, and the level of electrical load.
Power and Control Sections
Mechanical services switchboards consist of two main sections: the power section and the control section. The power section is responsible for managing the electrical power distribution, while the control section manages the electrical control signals for HVAC equipment and other building services.
The Power Section
The power section of a mechanical services switchboard contains several essential components, including the isolator, circuit breaker, bus bar, chassis, submain, and outgoing circuits.
The isolator is used to isolate the switchboard from the mains power supply, allowing for safe maintenance and repair work.
The circuit breaker protects the switchboard from power surges and other electrical faults. If a fault is detected, the circuit breaker will automatically trip, cutting off the power to the switchboard.
The bus bar is responsible for distributing power from the incoming cable to the various circuits within the switchboard. It is usually made of copper and is designed to handle high current loads.
The chassis is the frame that holds all the components of the switchboard together. It is typically made of steel and is designed to be strong and durable.
The submain is a cable that connects the switchboard to the main distribution board. It carries power from the switchboard to other areas of the building.
The outgoing circuits are the cables that connect the switchboard to individual pieces of HVAC equipment, such as air conditioning units and fans.
The Control Section
The control section of a mechanical services switchboard is responsible for managing the electrical control signals for HVAC equipment and other building services. It typically contains several components, including contactors, relays, and timers.
Contactors are used to control the power to HVAC equipment. They allow for the safe switching on and off of equipment, and they can also be used to control the speed of fans and other motors.
Relays are used to switch the control signals for HVAC equipment. They are responsible for turning equipment on and off and for controlling the temperature and humidity of the building.
Timers are used to control the timing of HVAC equipment. They can be used to turn equipment on and off at specific times of the day, or to adjust the temperature and humidity of the building based on the time of day.
In Conclusion
Mechanical services switchboards are essential components of any building's mechanical systems. They are responsible for managing the electrical power distribution and control for HVAC equipment, as well as other building services. The different form factors of mechanical services switchboards make the choice of switchboard type important to ensure the proper level of protection and functionality for the specific installation
