Calculate and look up the maximum permitted Zs value ( earth loop impedance ) to BS 7671. Max Zs Values also includes the 80% temperature adjusted values and a some MCCB 60947-2 manufacture Zs charts. - 100% BS 7671 Zs Values - 80% On Site Guide Zs Values - Printable 60947-2 MCCB Zs Tables - 0.4 (s) second disconnection times - 0.2 (s) second disconnection times - 5 (s) second disconnection times > Common BS EN Devices: Scroll through the list of protective devices and select the device rating to calculate the maximum permitted Zs value for your selected protective device and rating combination. > 60947-2 MCCB's Zs Tables: Look up the maximum permitted Zs tables for a selection of MCCB manufacture devices (some). Maximum Zs Features: + Maximum Disconnection Times + BS 7671 18th Edition Zs Tables + Fuse's + MCB's + RCBO's + RCD's in TT earthing systems + Max REC Ze values + 100% values + 80% values + 0.4 second disconnection times + 0.2 second disconnection times + 5 second disconnection times + Uo 55v (U 110v) single phase and Uo 63.5v (three phase) Zs values + BS EN 60947-2 MCCB manufacture device charts (some) There is now a new "Zs Converter" to convert old Zs values to the new 18th edition 230v Cmin Zs values. A maximum Zs calculator for iPhone and iPad. Check out our collection of electrical apps such as the "Pro Certs" Electrical Certification App for iPad.
