An apparatus includes a first terminal configured to be coupled to a substation around mat for a substation and a second terminal configured to be coupled to a safety around mat for a piece of electrical equipment powered by the substation. The system further includes at least one voltage-dependent resistance device, such as at least one metal oxide varistor (MOV) configured to be coupled between the first and second terminals. At least one circuit interruption device, such as a fuse and/or a disconnect switch may be coupled in series with the at least one voltage-dependent resistance device.