What is the maximum earth fault loop impedance Zs for the Tesys U? What values are taken into consideration to calculate the Zs values?

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What is the maximum earth fault loop impedance Zs for the TeSys Ultra? What values are taken into consideration to calculate the Zs values?

The charts below detail the earth loop impedance (Z_s) for the TeSys Ultra range for any TN system based on BS7671:2008+A3:2015

Two documents are also attached:

1) Z_s tables of TeSys motor circuit breakers:

TeSys GV2
TeSys GV3
TeSys GV4
TeSys GV7
TeSys U

2) Explanation of the calculation of the maximum earth loop impedance. This also includes additional information about:

Motor rated devices
Ambient temperature

Please refer to the table below which details the maximum earth loop impedance (Z_s) for 0.4s disconnection time with U_o 230V

Zs values table for TeSys Ultra

Updated TeSys starter picture - colour change

Released for:Schneider Electric Netherlands

Attachment(s)

Tesys Zs Values.pdf

[139.87 KB]

Zs v201810.pdf

[456.56 KB]

Published on:15/02/2012Last Modified on:22/08/2025

Range:

TeSys U

Range:

TeSys U