The Raritan Blog

Why the Hybrid Rack Transfer System is Superior to Both ATS and STS Systems

Posted on June 4, 2014 by Michael Bord

Lots of data center vendors offer transfer switches, but they normally fall into one of only two categories: relay-based Automatic Transfer Switches (ATS) or Static Transfer Switches (STS) that rely on silicon-controlled rectifiers.  Although effective in switching between power feeds, they both have inherent design flaws that hinder both performance and reliability – two areas where a hybrid rack transfer switch really excels.  But, to understand why the hybrid transfer switch is superior, you first need to understand the limitations of ATS and STS devices.

ATS switch transfer times vary from 10 to 16ms, and switching requires an additional 4 to 5ms, often exceeding the 20ms needed to keep IT equipment running making it a potential liability. Another disadvantage is that the contact and pole often fuse together due to electrical arcing; it’s one of the leading causes of relay-based ATS failure. And since ATS do not indicate when the relay has fused and is no longer able to switch power feeds, data center operators only know their transfer switch has failed when it’s too late!

STS systems offer very fast transfer times - normally 4 to 6ms.  But, there’s a huge trade-off here in terms of price; they are often over five and a half times more expensive than relay-based switches!  Another major downside is that they draw significantly more energy than relay-based switches and thereby produce more heat, forcing you to provide greater power and cooling resources than you may have the capacity for.

So, it’s easy to see why ATS and STS systems fall short of the mark.  But why is the hybrid rack transfer switch a better solution for your data center power management system? Consider the following points:

  • A hybrid automatic transfer switch combines electromechanical relays and silicon-controlled rectifiers providing a speedy transfer at 4 to 8ms, virtually identical to the STS, at a much lower cost.
  • The hybrid system offers oversized relays and air gaps that are nearly five and a half times wider than on the majority of relay based switches on the market – eliminating electrical arcing that leads to transfer failure.
  • Hybrids also offer surge protection, field replaceable fuses, and disaster recovery in case of shorted load. They’re also energy efficient and thereby produce less heat resulting in fewer considerations during installation and day-to-day use.

Thus, it’s clear to see how the hybrid transfer switch cleverly uses the qualities of both electromechanical relays and silicon-controlled rectifiers to maximize the positive and minimize the negative characteristics of each type of switch for the kind of performance and reliability you should demand in your data center power chain.

 

Learn more about Raritan’s innovative hybrid rack transfer switch or speak to a data center power management expert today!

Other Blog Posts

What Happens When Energy Consumption Leads To Unnecessary Spending?
Posted on January 8, 2019
What Happens When A University Needs A More Effective Approach To Data Center Locations And Management?
Posted on December 27, 2018
5 Critical Steps to Safeguard Against Weak Links In Your Security Policy
Posted on December 13, 2018
Dominion SX II: Raritan’s Next Generation Serial Console Server
Posted on December 6, 2018
The Importance of Data Center Colocations in Your Hybrid Environment
Posted on November 21, 2018

View all Blog Posts

Subscribe


Upcoming Events

West 2019
February 13 - 15  •  San Diego, CA
Data Center World Global 2019
March 19 - 22  •  Phoenix, AZ
Data Center Dynamics NY
April 9 - 10  •  New York, NY
National Association of Broadcasters Show
April 6 - 11  •  Las Vegas
Interop 19
May 20 - 23  •  Las Vegas, NV

View all Events

Latest Raritan News

Raritan Extends Reach of Remote Server Management with New KVM Product
Posted on November 26, 2018
Raritan Expands Intelligent Rack Management Portfolio with New Electronic Locking System for Equipment Cabinet Doors
Posted on July 26, 2018
Legrand Makes 451 Research’s List of Largest Data Center Technology Suppliers
Posted on May 4, 2018
Finding Weak Links in Your Security Policy and How to Safeguard Data Centers Will Be Addressed by Raritan Speaker at AFCOM Conference
Posted on March 8, 2018
Raritan Introduces Secure Switch for KVM Access to Government and Military Computers
Posted on March 6, 2018

View all news