Since amendment 1 of the 17th edition of BS7671:2008 back in January 2012, there has been a wider requirement for the installation of surge protection devices (SPDs). Arguably, this change was to become one of the most significant changes to the wiring regulations for some time.
Fast forward to 2024 and after numerous committee meetings, the launch of the 18th edition of BS7671 (and further amendments), most consumer units on the shelf now have an SPD device protecting the circuits and equipment within an installation.
So how do we go about testing SPDs? Currently, the guidance set provided in section 2.5.2 of The IET’s Guidance Note 3 - BS7671:2018+A2:2022 - at the time of writing, is as non-committal as ever (excuse my satire). It advises that apart from simple installations, other surge protection installations are typically designed and installed by specialist suppliers in accordance with BS EN 62305, and in these cases, advises inspectors to review the type of SPD against the scheme documentation provided by the specialist suppliers, and to review their test and commissioning documentation.
So, specifically there is no guidance on testing the devices if you’re completing an installation certificate or a condition report. Surely, if an SPD is classed as a safety device, you’d want to make sure that it works before signing off, and not solely rely on the indicator built within? I know I would.
Manufacturers of SPDs seem quite reluctant to release any test and measurement guidance, and for good reason. If a test instrument does not have the correct SPD test setting, there is a risk of damaging the devices permanently if a typical insulation resistance test is carried out. Therefore, it’s important to understand the differences between a typical insulation resistance test and a surge protection device test.
I reached out to Marc Sherwood, Senior Technical Manager at Fluke, for his view. Marc explains “SPD testing is actually a very simple two wire test. Unlike an insulation resistance test which outputs the selected test voltage almost instantaneously, the instrument very gently ramps up the test voltage and detects when current flows. This point is displayed along with the equivalent value in AC and can be recorded if required.”
Subsequently, the flagship model 1674FC of Fluke’s new touchscreen MFT range boasts the SPD test setting, if required. And this is just one unique feature within a myriad of other time-saving test features that Fluke’s new 1670-series boasts.
Check out the new range here and don’t hesitate to contact us on 0113 248 99 66 if you have any enquiries we can help with.
About the Author
Chris Fox is a Master Electrician and Business Development Manager at Test Meter Group. He is passionate about building lasting relationships through his ability to deliver tailored solutions that exceed client expectations. Outside of work, Chris is an avid mountaineer, finding solace and adventure in the great outdoors.