What are Bypass Switches? How do they work?

Bypass switches are important components of various technical systems designed to ensure uninterrupted operation and reliability. These switches offer another route to carry power or data, on occasions when continuity is imperative. Bypass switches are used in uninterruptible power supply systems, data centres, and numerous industrial applications to separate smooth transitions for things like maintenance, repairs, or random outages of power sources. Only by knowing how bypass switches work—whether they can help redirect power flow effectively or what contributions they make toward making whole systems more robust and efficient—you can take different measures for any particular application.

What is a Bypass Switch?

A bypass switch is an external software controller designed to provide a hardware access port for a live active network security device, such as an intrusion prevention system (IPS) or next-generation firewall (NGFW). In-line security appliances pose a weakness in live computer networks because a power failure, software crash, or a decision to update them can disturb the flow of traffic through the essential connection. The bypass switch overcomes this vulnerability by automatically putting the traffic in bypass mode whenever necessary to keep the crucial network link up.

How Bypass Switch Works?

The Static Bypass Switch is a component found in Online UPS systems that plays a crucial role in maintaining continuous power flow. It automatically reroutes the power from the main supply, bypassing the UPS system when there's an internal issue or failure. This means essential digital functions can continue to operate while necessary repairs or replacements are completed on the failed UPS system.

Online UPS bypass switches often feature this mechanism because it allows for the instantaneous transition of load towards mains electricity during issues, including malfunctions within the UPS itself or short circuits. Once these difficulties are resolved, the switch will then bring back electrical supply management to its regular state with ease. 

It's essential not to confuse external maintenance bypass switches and internal static ones since their roles are different although serve one root – continuity of power provision. This manual device takes various shapes like circuit breaker sets, wraparound switches, and rotary switches but all have the same utility – enabling manual uptake control if required while consumers continuously receive direct power regardless of intervention event progress.

Types of Bypass Switches

Two primary types of bypass switches fulfil similar yet distinct functions: the static bypass switch and the external maintenance bypass switch.

• The static bypass serves as a failsafe for the inverter. In the event of inverter failure, the load automatically shifts to the mains input feed, ensuring uninterrupted power. Typically integrated into the internal circuitry of almost all online UPS systems, it includes an external switch for manual invocation, providing an added safety measure against inverter failure. While not ideal for repair purposes, as the majority of the UPS remains connected to power, it proves effective in safeguarding against inverter issues.
• On the other hand, the external maintenance bypass switch is affixed to the exterior of the UPS, sometimes referred to as a wraparound bypass. This bypass facilitates continuous power flow while the UPS is isolated and easily detachable for repairs. Using this switch avoids the need to power down the entire network, preventing prolonged downtime and significant costs for some businesses. Additionally, in the rare event of a UPS fault, this switch ensures a safe transfer of the load, making the unit easy to remove and replace.

Uses of Bypass Switches

Here are some common uses of bypass switches:

1. Bypass switches form a critical part of a functioning UPS system. In cases where a failure occurs or even if scheduled maintenance is occurring of a UPS, bypass switches ensure that electrical load passes directly onto the mains power source and hence the provision of uninterrupted power supply is not interrupted for any essential equipment it was hooked to.
2. Bypass switches play a significant role in enabling a continuous supply of uninterrupted power to servers and networking equipment in data centres. A bypass switch enables an easy, fast, and secure transition from the use of generator power or other resources such as utility power.
3. In case of scheduled maintenance or repair of electric equipment, a bypass switch helps the technicians redirect power without an interruption in the supply meant for connected devices. Thus it helps in reducing the downtime and makes sure that the shifting from one source to another is hassle-free.
4. Bypass switches normally find applications in load testing situations whereby the test aims to simply bypass the load around a system or component, given its test. In this analogy, they allow in-depth examination without interfering with the normal routine operation of the whole system.
5. In an industrial environment, however, especially when uninterrupted operation is necessary for economic considerations, bypass switches are installed to reroute power in the event of failure of a given equipment or in case it should be taken out for maintenance. The idea behind this is that it will then still be possible to continue the production process with little disturbance.

Advantages and Disadvantages of Bypass Switch

While bypass switches have several advantages it also has a few disadvantages. In this section, we will highlight both the advantages and disadvantages of bypass switch:

Advantages

• Continuity to Network Traffic: An external bypass switch can be connected with NGFW, IPS or DDoS, which will chain the in-line appliances together and hence there will be a couple of advantages. In the case that functionality tumbles into one inline equipment, it will not affect network traffic and hence the appliance can be serviced or removed without stopping the network traffic.
• Maintenance Flexibility: In the event of an IPS requiring upgrading, maintaining, or troubleshooting, an external bypass switch allows these with no instigation of any interruption in network traffic. Further, moving in-line hardware from one to another segment can be effected without affecting network operations.
• Internal Bypass-Switch Systems Not Providing Functionality: Examples, where NGFW/IPS appliances that employ internal bypass-switch functionality do not provide functionalities, include the ability to take down an IPS system for updates nor reposition in-line hardware between network segments without affecting traffic.

Disadvantages

• Versatility: Various bypass TAPs providing aggregation, regeneration (SPAN), breakout (standard) and others in various configurations will have different configurations at the life of the network.
• Increased Cost: Even though bypass switches and TAPs can significantly increase the uptime of the network for lower costs in the long run it also increases the general cost of the monitoring system.
• Single Point of Failure: Bypass switches convert a single point of failure from the bypass switch of in-line monitoring equipment. As a more specialised device that is designed for fault tolerance, it brings up dependency.

Bypass Switches from Lauritz Knudsen (Formerly L&T Switchgear)

Bypass switches are available in various amperages and with different options to cater to different electrical requirements. And to have hassle-free shopping for the best bypass switches, check out Lauritz Knudsen (Formerly L&T Switchgear). We have a CZ SD & Bypass Switch Auxiliary Contact Kit which has 1 C/O contact. Furthermore, the 4P configuration, as well as 440 Vac rating CZ2 Bypass models, are available in a variety of amperages from 630A, 400A to 315A. These switches divert power without a hitch when something needs cleaning or happens to break down. But these are not all, we have more in store for you to easily navigate through and have a satisfying shopping experience. 

Also Read: What Is A Changeover Switch And Its Function?

FAQs:

Q1. What are static bypass switches, and where are they used?

Ans: Static bypass switches refer to the electrical devices that allow the transfer of a load between a primary power source and an alternate source. They allow this transfer without interrupting the power supply. They are commonly used in Uninterruptible Power Supply (UPS) systems to ensure continuous power delivery during maintenance or faults in the primary source. These switches provide seamless transition to help maintain critical operations in data centres, hospitals, and other sensitive environments.

Q2. Are bypass switches manual or automatic?

Ans: Bypass switches can be either manual or automatic. Manual bypass switches require human intervention to transfer the load between power sources. These are usually used during planned maintenance. On the other hand, automatic bypass switches detect issues with the primary power source and automatically switch to the backup source without human intervention.

Q3. What are the common challenges associated with bypass switches?

Ans: Common challenges associated with bypass switches include improper installation. This can lead to electrical faults, and the risk of accidental activation, causing unexpected power interruptions. In automatic systems, a malfunctioning switch can fail to transfer the load correctly, leading to downtime. Additionally, bypass switches require regular maintenance and testing to ensure reliability, and they must be appropriately rated to handle the electrical load without overheating or causing circuit damage.

Q4. How do manual bypass switches differ from automatic bypass switches?

Ans: Manual bypass switches require human intervention to operate. They are typically used for planned maintenance or troubleshooting, allowing operators to control when the load is transferred. Automatic bypass switches, however, detect faults or power failures and automatically switch to an alternate source without manual input. While manual switches offer more control, automatic switches provide faster response times, which is essential in environments where continuous power is critical, reducing the risk of downtime.

Q5. What are the key factors to consider when installing a bypass switch?

Ans: When installing a bypass switch, key factors include ensuring the switch is correctly rated for the electrical load to prevent overheating or failure. The installation location should be easily accessible for maintenance but secure to avoid accidental activation. Consider the type of switch based on the application’s needs. Additionally, ensure compatibility with the existing power system, and follow safety standards and regulations to ensure reliable and safe operation.