Automatic power by-pass units in wall-mounted and rack-mounted configurations are being designed and manufactured for the South African market by uninterruptible power supply (UPS) specialist Square One Power Solutions.
Reliance on computers and electronic technology to conduct business has created the demand for automatic by-pass units. Retail operations, particularly large supermarket and department store chains that operate many cash tills, now tend to specify by-pass units as an essential component of their UPS requirements.
"Automatic bypass installations are also essential for other business applications when the operations are such that they cannot tolerate any downtime," said Neil Burnard, managing director of Square One Power, a company in the JSE-listed Square One Solutions Group.
"Any operation that requires critical reliability and predictable performance from computers, telecommunications equipment, office equipment such as routers and digital copiers and in industrial applications, programmable logic controllers (PLCs) and distributed control systems (DCS), has a motivation for installing bypass power as well as UPS."
An automatic bypass unit permits "daisy chaining" with any UPS, providing bypass to conventional AC circuits or generator-supported AC circuits and ensuring uninterrupted AC to the load even in the unlikely event of a UPS failure. It takes mains power in and supplies power out to the UPS unit, which sends clean power free of voltage variance back to the bypass from where it is routed to computers, cash tills, digital copiers, PLCs and other critical equipment.
"The by-pass units are fitted with four circuit-breakers -- a mains breaker and three subsidiaries," said Burnard. "The automation function ensures the by-pass unit will feed corrected clean power from the UPS and that it will switch to mains supply in the unlikely event of a UPS fault or overload. The unit then automatically reverts to clean UPS power when the fault is rectified."
The system provides additional peace of mind for the user because the bypass ensures that maintenance work on the UPS installation or its replacement can be carried out without taking the user's system off line.
"A bypass will provide uninterrupted AC to the load even if the UPS happens to fail. It protects critical equipment against extended power outages and catastrophic system shutdowns caused by events such as accidental circuit breaker trips, weak or old UPS batteries, accidental UPS shutdown or loose power connections."
When the primary power (UPS) source detector circuit in the bypass unit senses loss of power on that circuit, a contactor with mechanical interlock switches the load over to the mains power source feed in less than 10 milliseconds. Burnard said the speed of this switchover is invisible to computer switch mode power supplies, so the system remains online.
Increasing demand for rack-mounted UPS solutions prompted Square One Power to design and manufacture a rack-mounted by pass unit on a standard 19-inch rack which slots in above the UPS.
The automatic bypass units have a flashing red LED and audible alarm warning system that ensures users switch the unit back to UPS source from mains after it has been manually switched over to mains to allow UPS maintenance or replacement without going offline.
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Square One Power Solutions is a national UPS and facility services integrator, an APC High Power Partner and a member of the JSE-listed Square One Solutions Group. It provides power solutions for the SOHO, PCA and SME network environment, telecommunications, medical, security, lighting and general industry as well as major corporations and government.
The Square One Solutions Group focuses on providing IT-based business enabling solutions. The company has a national footprint and more than 18 years of experience of the South African market. Square One offers value-based solutions centred around biometric authentication; integrated wireless and mobile applications; enterprise storage and backup/recovery; enterprise power; coding and marking; and enterprise LAN, WAN and infrastructure for the corporate, SME and government markets. The company also distributes document solutions, colour input and output devices and provides 24x7 national support and service.
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