The last year has been a time of changing standards and regulations for electrical testing, as Steve Dunning from Martindale explains.
The latest changes to the 17th Edition of the Wiring Regulations, Amendment 3, which came into full effect during the summer, have had an impact on the way testing is carried out. Fast and reliable testing of RCDs has become even more important with the increased use of RCDs where there are concealed cables and with the requirement for the protection of all socket outlets up to 20A in dwellings. New multifunction testers with auto RCD testing and the capability to display all results on one screen now make it easier and quicker to get the job done.
From a testing perspective, one of the most important changes is a reduction in all maximum earth loop impedance values, Zs, for protective devices. The new values take into account that the supply voltage can dip below 230V, in which case, the necessary disconnection times required to prevent electrocution may not be achieved at the old pass/fail loop impedance values. From a practical point of view, the benefits of using a multifunction tester which has the latest maximum loop impedance values built-in, significantly reduces the risk of errors, by removing the need to cross reference complex tables for different devices and ratings. The latest ET4000 multifunction installation testers from Martindale have both the latest values built-in and clear red/green pass fail indicators, enabling you to work smarter and faster on-site.
“The new regs also mean new certificate pads for the verification of electrical installation and changes to PC software for the auto-filling of certificates. ET-Link PRO software from Martindale includes the latest Amendment 3 certificates and comes as standard with ET4500 PRO multifunction tester package.”
The new regs also mean new certificate pads for the verification of electrical installation and changes to PC software for the auto-filling of certificates. ET-Link PRO software from Martindale includes the latest Amendment 3 certificates and comes as standard with ET4500 PRO multifunction tester package.
What’s new in GS38
The Health & Safety Executive Guidance Note GS38 has been fully updated in June 2015 to clarify the latest safety standards for electrical test tools and accessories and precautions that need to be taken to stay safe. It’s aimed at electricians and other trades and gives advice and guidance on how to work safely and ensure the right equipment is used and maintained properly. It also provides details of the risks associated with the use of unsatisfactory test equipment and includes a list of safety precautions and requirements all professional electricians should be aware of. Clearly it’s in everybody’s interest to 
comply and ensure you and your employees stay safe.
There are some changes that could affect the way you test, or the equipment you are using. There is a new ‘Test Equipment’ section with the focus on selecting the correct equipment and more information on the common causes of accidents including using equipment and accessories not rated to the right installation category, using damaged or modified leads and using multimeters for safe isolation.
When it comes to safe isolation, GS38 now references the latest standard for voltage indicators, BS EN 61243-3, requiring a resistor to limit the current in the event of damage to the cable, as opposed to a fuse. This is much more effective at limiting the current that can flow under fault conditions, particularly when the resistor is built-in to the handheld probe as is the case with Martindale voltage indicators. It’s also made clear that non-contact voltage sticks should never be used for safe isolation procedures and highlights accidents caused through the use of multimeters and other test equipment which have switchable ranges and require batteries for voltage indication. The need to prove your voltage indicator before and after use is also now strongly emphasised.
Get the right kit
Other changes include making sure that test equipment and leads are to the right safety installation category for the application. This is an important safety issue as using equipment that is not correctly rated for the installation category can, and has resulted in serious injury and death. It’s also important to understand that using CAT II rated test leads connected to a CAT III rated instrument would not be suitable for testing a CAT III installation. Clarification of the different installation categories and where they apply is included in the guidance note and the new 2016 Martindale test equipment catalogue.
Choosing your next set of test equipment can be a minefield. To simplify the whole process Martindale has put together a range of safe isolation kits suitable for all installation categories and introduced 17th Edition testers with the latest Amendment 3 limits built-in.
