{}

Our Brands

Welcome to the Schneider Electric Website

Welcome to our website.
How can we help you today?
What is Class 5 timing accuracy as described in the Sepam Operation manual?
Issue
User needs clarification of what Sepam class 5 timing accuracy is as a percentage

Product Line
Sepam series 20, 40, and 80

Environment
Accuracy specifications

Resolution
Class 5 accuracy is defined in the IEC 60255-151 standard. Class 5 accuracy is ±5%.

This 5% has factors to be considered referring to different parts of the IDMT curve. These factors are defined in part 5.2(Accuracy related to the operate time) table 1 IEC60255-151(2009). This table is provided below.

This table gives the factors for different ranges (Gs= threshold). To determine the real accuracy, multiply the assigned error of 5% by the limiting error from the above table. The assigned error is based on the accuracy class 5 for the Sepam relay. The real accuracy values for each of these ranges is below:
  • For current between 2 to 5, real accuracy would be 2.5*5% = 12.5%
  • For current between 5 to 10, real accuracy would be 1.5*5% = 7.5%
  • For current higher than 10*Gs or 10 times threshold, real accuracy would be 1*5% = 5%

Schneider Electric Nigeria

What is Class 5 timing accuracy as described in the Sepam Operation manual?
Issue     
User needs clarification of what Sepam class 5 timing accuracy is as a percentage

Product Line    
Sepam series 20, 40, and 80

Environment   
Accuracy specifications

Resolution
Class 5 accuracy is defined in the IEC 60255-151 standard. Class 5 accuracy is ±5%. 

This 5% has factors to be considered referring to different parts of the IDMT curve. These factors are defined in part 5.2(Accuracy related to the operate time) table 1 IEC60255-151(2009). This table is provided below. 

This table gives the factors for different ranges (Gs= threshold). To determine the real accuracy, multiply the assigned error of 5% by the limiting error from the above table. The assigned error is based on the accuracy class 5 for the Sepam relay. The real accuracy values for each of these ranges is below:
  • For current between 2 to 5, real accuracy would be 2.5*5% = 12.5% 
  • For current between 5 to 10, real accuracy would be 1.5*5% = 7.5% 
  • For current higher than 10*Gs or 10 times threshold, real accuracy would be 1*5% = 5% 

Schneider Electric Nigeria

Explore more
Range:
Explore more
Range:
Users group

Discuss this topic with experts

Visit our Community for first-hand insights from experts and peers on this topic and more.
Users group

Discuss this topic with experts

Visit our Community for first-hand insights from experts and peers on this topic and more.
Explore more
Range:
Explore more
Range:
Your browser is out of date and has known security issues.

It also may not display all features of this website or other websites.

Please upgrade your browser to access all of the features of this website.

Latest version for Google Chrome, Mozilla Firefox or Microsoft Edgeis recommended for optimal functionality.
Your browser is out of date and has known security issues.

It also may not display all features of this website or other websites.

Please upgrade your browser to access all of the features of this website.

Latest version for Google Chrome, Mozilla Firefox or Microsoft Edgeis recommended for optimal functionality.