Technical FAQs

Ask a Question

What is the maximum earth fault loop impedance Zs for the Tesys GV7? What values are taken into consideration to calculate the Zs values?

The charts below detail the Earth Loop impedance (Zs) for the GV7 range for any TN system based on the British Standard BS7671:2008+A3:2015

Two documents are also attached:
1) Sheet with Zs charts of Tesys motor circuit breakers:
  • Tesys GV2
  • Tesys GV3
  • Tesys GV4
  • Tesys GV7
  • Tesys U
2) Explaination of the calculation of the maximum Earth Loop Impedancee
This also includes additional information about:
  • Motor Rated devices
  • Ambient Temperature
Tesys GV7 Range
Please refer to the charts below that detail the maximum earth loop impedance Zs for 0.4s disconnection time with Uo 230V
GV7
Reference Thermal Adjustment
Range In
Magnetic Tripping Current Im Tolerance
Im+20%
Maximum Loop
Impedance Zs
  (A) (A) (A) (Ω) 
GV7RE150 90 .. 150   2520 0.09
GV7RS150 90 .. 150  
GV7RE220 132 .. 220   3696 0.06
GV7RS220 132 .. 220  
Was this helpful?
What can we do to improve the information ?