Expert blogs

Hot Swap Redundancy: Reliable power supply for critical loads

In the digital age, where datacentres and hospitals form the backbone of our modern society, maintaining a constant and reliable power supply is of paramount importance. 

Imagine if the power control system for such critical installations were to encounter a sudden failure. This might lead to immediate power disruption and outage for essential services. The consequences could be dire, potentially resulting in data loss, compromised patient care, or even life-threatening situations. 

How can these potential risks to the stability of critical systems be mitigated? One solution would be to adopt Hot Swap Redundancy in your power control systems. In this article, we will delve into the necessity of redundancy in critical installations and showcase how ComAp’s advanced controllers safeguard against power disruptions with this feature and a specific failover process.

The Risks of Insufficient Redundancy

As a first step, it is crucial to understand the potential risks associated with an inadequate power generation control system for mission critical applications, such as datacentres and hospitals. Some of the risks are:

  • Downtime and Data Loss: In datacentres, an unexpected power failure could lead to server downtime and data loss. This could severely impact business operations and client services for the company using the datacentre. Data recovery can be time-consuming and costly, making it essential to prevent such occurrences.
  • Disrupted Medical Services: Hospitals depend on continuous power for life-saving equipment, patient monitoring systems, and electronic medical records. A power outage could jeopardise patient safety and hinder critical medical procedures.
  • Financial Loss: Power-related disruptions can mean significant financial losses, both in terms of direct operational costs and potential damage to an organisation's reputation. For example, in 2017, due to a single datacentre blackout in the UK, British Airways needed to cancel over 400 flights for roughly 75 000 passengers. That lead to additional costs of more than 100 million euros for the airline.  

Understanding the gravity of these risks, our team at ComAp has developed an advanced power generation control system that incorporates Hot Swap Redundancy and ensures uninterrupted power supply even in the face of unforeseen controller failures.

Hot Swap Redundancy: How does it work?


Our control system consists of a Primary controller and a Backup controller, operating in harmony to maintain a reliable power supply. The Backup controller continuously monitors the heartbeat (fast signal, which indicates proper function of the controller) of the Primary controller. If any abnormalities or failure of the Primary controller are detected, the Backup controller immediately takes over control without missing a beat.

Wiring diagram for Hot Swap redundancy

Seamless Failover Process

During regular operation, both the Primary and the Backup controllers share the generator output values over the CAN1B line. This ensures that the Backup controller is always aware of the precise state of the generator. When the Primary controller fails, the Backup controller takes over and utilises the up-to-date information it has been continuously receiving to maintain a continuous transition of power control.

To better illustrate the effectiveness of our Hot Swap Redundancy, you can see the below chart showcasing the outputs of both the Primary and Backup controllers. The chart data comes from ComAp’s internal validation of the Hot Swap functionality and shows clearly how the Speed Regulator Output (SRO), and the Voltage Regulator Output (VRO) are shared between the Primary and the Backup controller. 

Hot Swap redundancy chart showing outputs of both primary and backup controllers.Hot Swap redundancy chart showing outputs of both primary and backup controllers.

ComAp’s innovative Hot-Swap redundancy solution helps to maintain the stability of critical installations and ensure the critical load will be strong enough to tackle any power-related challenges that may arise.  The best defence against power disruptions is a proactive and robust redundancy solution, where seamless continuity is the ultimate power.

Interested in adopting Hot Swap redundancy to protect your power control systems? Contact us and let’s discuss how we can support your project. 



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