Category: BS 7671

Zs Converter

Convert Old Zs Values to 18th Edition Zs Values

Convert Zs values from a previous version of BS 7671 to BS 7671 18th edition 230v Cmin values.

Bathroom Zones

Bathroom Zones

Bathroom zones and the specification and minimum requirements of electrical equipment within a room containing a bath or shower.

BS 7671 Reference Methods

BS 7671 Reference Methods

Installation Reference Method table for your electrical certificates & determining the current carrying capacity of a cable.

Cable Limiting Temperature Time Calculator

Protection Against Exceeding Cable Limiting Temperature

Calculate how long a cable will take to reach its limiting temperature under fault conditions.


AFDD Max Zs Values

Here we answer a common question we keep getting asked: What is the max Zs for AFDD’s?

Sockets in a Bathroom

Socket in a Bathroom

Are sockets in bathrooms permitted or not? Read more to find out if a socket is permitted in a bathroom.

Spurs in a Bathroom

Spurs in Bathrooms

Are spurs in bathrooms permitted? Yes, but only if certain conditions are met, read more to find out what those conditions are.

BS 7671 18th Edition Amendment 2

Pre-order BS 7671 Amendment 2 2022

BS 7671 18th Edition Amendment 2 2022 is now available to pre-order.

Maximum demand diversity

How to calculate diversity and maximum demand

Diversity Calculator App. How to calculate total connected load, apply diversity and calculate the maximum demand, with examples. Download for iOS + Android.

Cooker Switch Behind Oven

Cooker Switch Distance from a Hob or Cooker

Guidance on the minimum distances electrical accessories such as sockets and switches can be installed from an oven, hob or free standing cooker.