What is it and how does the Mains/Genset switching work?

Mains/Genset switching is a key process in the installation of gensets, ensuring continuous power supply during grid failures. This mechanism is essential in critical sectors, where a lack of electricity can cause serious problems.

In this article, we explain in detail what Mains/Genset switching is, the different types of systems, and how to choose the most suitable for your installation.

What is a Mains/Genset switch?

Concept and definition

Mains/Genset switchover is the process of switching from the main power source (the mains) to a backup power source (the genset) when a mains failure is detected. This switching can be done manually or automatically and ensures continuity of power supply.

Importance in uninterruptible power supply

This process is essential in facilities that cannot afford a prolonged power outage, such as hospitals, industries or data centres. Thanks to switching, the generator set is activated to ensure that power continues to flow without interruption, avoiding economic losses and possible damage to sensitive equipment.

Mains/Genset switchboards and diagrams

Mains/Genset switchboard: Function and components

The switchboard is an essential device in this process. It is composed of two power inputs: the mains and the generating set, and an output which distributes the electricity to the loads. While the grid is in operation, the switchboard keeps its input active, but in case of failure, it switches to the genset input.

Types of switching systems

Based on their operation, there are 3 types of switching systems:

• Manual: Requires human intervention to switch from mains to genset.
• Automatic: The system acts automatically as soon as it detects a mains failure.
• Remote: Allows remote switching, which can be useful in decentralised installations.

Manual (local) switching

This is the simplest switching system. Manual switching requires an operator to physically intervene to switch from the mains to the genset. This type of system is usually used in installations where power outages do not have a serious impact or in cases where simplicity and low cost are a priority. The operator, in the event of a mains failure, must operate a switch or device to start the genset and transfer the load.

Advantages of Manual Switching

• Reduced cost: Manual systems are more economical compared to automatic systems.
• Simplicity: They are easy to install and operate in non-critical environments.
• Direct control: The operator can decide when and how to switch.

Disadvantages of Manual Switching

• Slow response time: Requires human intervention, which delays the reactivation of the supply.
• Operator dependency: If no personnel are available, switching will not take place.
• Risk of errors: Manual operation can lead to errors, such as failures in the switching procedure.

Automatic switching

Automatic switchover is the most advanced and efficient option. This system is designed to detect faults in the electrical network immediately and switch over to the generator set without human intervention. It is ideal for installations where continuity of power supply is crucial, as the process is fast and avoids prolonged outages.

Advantages of automatic switchover

• Fast response: Switching is done in a matter of seconds, minimising outage time.
• Increased reliability: No reliance on human intervention, reducing the margin of error.
• Continuity of service: Ideal for critical installations where a prolonged outage could have serious consequences.

Remote switching

Remote switching allows remote switching between the grid and the genset to be performed remotely. This system is useful in decentralised installations or in large installations where physical access to the switching systems is not practical, such as telecommunications installations scattered throughout the territory.

The operator can activate the switching from a remote panel, a mobile device or via a programmed system.

Advantages of remote switching

• Remote access: The system can be controlled from any location, which facilitates management in complex installations.
• Operational flexibility: Can be integrated with other remote control and automation systems.
• Reduced physical intervention: Reduces the need for physical travel to the equipment location.
• Can be both automatic and manual (remotely).

Maintenance and considerations for Mains/Genset switching

Common problems and solutions in unstable networks

In areas with unstable power grids, switchboards can be damaged by constant power surges and outages. A common solution is to use surge arresters and opt for DC-supplied switchboards, which are less susceptible to mains fluctuations.

Maintenance of switchboards

Regular maintenance of switchboards is essential to ensure their proper functioning. It is recommended to check contactors and control relays, and to ensure that there is no wear or damage to coils or circuit breakers.

Mains/Genset switching is an essential component in any installation using generator sets as a backup power source. Selecting the right system and carrying out regular maintenance is key to ensuring that the power supply is continuous and uninterrupted.

Check this article for more information on connecting generators.