60947-2 Max Zs Charts

60947-2 Max Zs Charts

The maximum Zs tables and charts for BS EN 60947-2 MCCB’s varies between manufactures and specific to the MCCB part number, and again depending on the settings of the actual MCCB device.

Due to the many variables there isn’t a quick Zs calculation for 60947-2 MCCB (molded case circuit breaker) or ACB (air circuit breaker) protection devices.

In order to obtain the correct Zs value for ACB’s and MCCB’s based on BS 7671 Amendment 4 (A4:2026) you need to refer to the manufacturers data table for the specific device part number and specific device settings.

Amendment 4 was published on 15 April 2026, and the previous edition is withdrawn on 15 October 2026

Trying to locate the Zs value for a BS EN 60947-2 MCCB or ACB can be extremely time consuming, therefore we designed and developed the Max Zs App which includes all common protective devices such as MCB’s, Fuses and RCBO’s, along with a selection of manufacture specific MCCB’s, the Max Zs Values app is available on iPhone, iPad and Android

Stop wasting hours searching for MCCB Zs tables. Get instant access to our database of tables with our Cloud Electrical Software.

Zs Values for 60947-2 MCCB’s

We have a number 60947-2 Max Zs charts from different MCCB manufacturers, such as Hager, Merlin Gerin, Dorman Smith, Siemens and Eaton, amongst many others.

Maximum permitted Zs for BS EN 60947-2 Protective Devices

BS 7671 A4:2026 maximum permitted Zs values for 60947-2 protective devices vary between different manufacturers, for instance 60947-2 Merlin Gerin Zs values are different to 60974-2 Eaton Zs values and 60947-2 Square D max Zs values are different to Dorman Smith and ABB max Zs values for example.

BS EN 60947-2 Zs Tables

Tables and charts for MCCB’s and ACB’s are normally available to download from the manufacturer’s website, on occasions you maybe able to phone the manufacturer who can point you in the right direction, ACB | MCCB | 60947-2.​

We have included some BS EN 60947-2 Zs tables within our Max Zs Values App where you can look up the Zs chart for the MCCB listed by the part number such as NSX250 or TMD160D. The MCCB Zs charts are grouped by manufacture for easy to find look up Zs charts for MCCB’s.