@efixx247: Why Switches Must Be ON During IR Tests Why do switches need to be in the ON position during insulation resistance testing? In this quick tip, Joe explains how leaving them OFF could mean missing parts of the circuit - and potentially missing faults. It’s a simple step, but it makes all the difference. Free Insulation Resistance Training 👉 https://hub.efixx.co.uk/TISIRCPD Check out the TIS MFT Pro 👉 https://hub.efixx.co.uk/TISMFTPRO #electricaltesting #electricalinstallation #electricaltraining