IET Code of Practice for In-service Inspection and Testing of Electrical Equipment, 5th Edition.

The core purpose of this Code of Practice is to help achieve high standards of electrical safety. It provides advice on in-service inspection and testing to determine whether electrical equipment is fit for continued service.

Among some of the changes reflected in this 5th edition are: the need for electrical equipment maintenance; changes to acceptable test result limits and the hierarchy of tests; suggestions for how to approach testing frequency and intervals; reaffirmation of the demarcation between equipment connected to a fixed electrical installation and the installation itself; greater emphasis and guidance regarding user-checks; and advice on the types of test available to duty-holders.