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Blog posts tagged with 'ATS Transfer Switches'

Keep Things Switched On: Thanks to Automatic Transfer Switches

An automatic transfer switch automatically switches between your primary and backup power sources. Here are some key points about ATS:

  •      Automatically transitions powered loads to a generator or other backup source during an outage
  •      Prevents back feed of power into utility lines during an outage
  •      Allows safe switching between power sources
  •      Provides seamless transition of power to prevent interruption

Used for any application where a power disruption would cause significant disruption, danger and high costs - like data centres, industrial processes, and infrastructure.

Why Are Automatic Transfer Switches Used?

There are several reasons why ATS are a common component of backup power systems:

They prevent injury and damage by preventing the back feed of power into utility lines. This protects workers who may be repairing lines.

They provide a quick, seamless transition to backup power. This avoids interruption and disruption to equipment and processes.

They require no manual intervention to switch power sources. The transition is automatic.

They may be required as part of backup systems for life safety systems in facilities such as hospitals

ATS Key Features and Options

There are several key specifications and options to consider when selecting an automatic transfer switch:

  • Transition Time - The time it takes to transfer loads to backup power. Faster times prevent interruption.
  • Withstand and Closing Ratings - The amount of current/voltage the switch can handle without damage. Matches the generator size.
  • Number of Poles - Single pole (2-wire) or multi-pole (3 or 4-wire) configurations are available. Matches the electrical system.
  • Enclosure Type - Indoor and outdoor rated enclosures to match the environment. Outdoor models provide more placement flexibility.
  • Controller Logic - Digital microprocessors that supervise and control the switching process. Provide precise timing and control.
  • Keypad Programming - Allows easy adjustment of the operating parameters and timing as needed.
  • Network Communication - Allows monitoring and control of the ATS remotely over a network for convenience.
  • Testing and Simulation - Used to periodically test the generator and ATS operation for reliability. Prevents problems.
  • Predictive Maintenance - Advanced models track operation metrics to catch issues early before failure. Maximises uptime.
  • Durability - Components designed to handle years of reliable switching cycles, temperature fluctuations, dirt, etc.

ATS are used in a wide variety of facilities across many industries and applications. Proper selection requires consideration of factors like transition time, withstand/closing ratings, number of poles, enclosure type, controller features, and more.

Our ATS specialists can help assess your specific needs and recommend the right model to suit your requirements.

Our specialists are ready to help assess your needs and ensure you get an ATS that meets the requirements of your emergency power, legally required, or mission-critical backup system.

How An Automatic Transfer Switch Works

If you are installing a standby generator on-premises with a mains power supply, it is a legal requirement to have a transfer switch. This can be either manual or automatic. This avoids the mains power burning out the generator which would be almost certain to happen if the mains power came back on while the generator was running, and it avoids the generator back-feeding the mains which would endanger the safety of the electricity utility workers.

Both types of switches perform the same function, but the automatic transfer switch obviously does it automatically, saving time and restoring power almost immediately. Furthermore, if you have a manual switch, it means that you have to be on the premises in order to start the generator, so if you are away there will be no power until you return and switch over.

There are two types of automatic transfer switches, or ATS, panels. One has mains detection built-in and monitors the mains supply. When it detects a mains failure it will send a signal to the generator to start. When the generator has started it then sends a signal back to the ATS saying that it is available, and the ATS will then switch to the generator.

If the ATS does not have mains detection built-in, this will have to be part of the generator and it will monitor the mains supply. When it detects the mains failure it will send a signal to the ATS to disconnect from the mains and start itself automatically. As soon as it is up and running it then sends a signal to the ATS telling it to switch to the generator.

There are a number of different designs of ATS panels, but usually, a mains failure relay is fitted with two contactors in an enclosure. The contactors are mechanically and electrically interlocked, and a mechanical device called an interlock ensures that the two contactors cannot be closed at the same time. If you have two contactors, A and B, the circuit to close contactor A is wired through the auxiliary of B, therefore when B is closed, it is not possible to energize A. The same is true for B which is wired through the auxiliary of A. This provides the electrical interlock.

When the mains fails and the generator starts, the ATS opens the mains contactor and closes the generator contactor. When mains power is restored, the reverse happens. Since the two contactors can never be closed together, there is always a short break in the supply as the contactors change over.