{
  "node": {
    "id": "term:extra-low-voltage",
    "type": "Term",
    "label": "Extra-low voltage",
    "properties": {
      "id": "extra-low-voltage",
      "name": "Extra-low voltage",
      "abbr": "ELV",
      "aka": [
        "SELV",
        "PELV",
        "FELV",
        "safety extra-low voltage",
        "protective extra-low voltage"
      ],
      "section": "topic-hvsafety",
      "definition": "Voltage low enough to need reduced shock protection: at most 50 V AC rms or 120 V ripple-free DC under IEC 61140. SELV is separated from higher voltages and from earth; PELV is separated but earthed; FELV is low in value only, without protective separation, so it is protected like the circuit feeding it. Vehicle rules draw their line lower, at 60 V DC.",
      "related": [
        "voltage-class",
        "insulation-resistance",
        "equipotential-bonding",
        "48v-system"
      ],
      "url": "https://lemonergy.com/learn/glossary/extra-low-voltage/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:5031",
      "source": "term:extra-low-voltage",
      "target": "topic:topic-hvsafety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5032",
      "source": "term:extra-low-voltage",
      "target": "term:voltage-class",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5033",
      "source": "term:extra-low-voltage",
      "target": "term:insulation-resistance",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5034",
      "source": "term:extra-low-voltage",
      "target": "term:equipotential-bonding",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5035",
      "source": "term:extra-low-voltage",
      "target": "term:48v-system",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    }
  ],
  "neighbors": [
    {
      "id": "topic:topic-hvsafety",
      "type": "Topic",
      "label": "High-voltage and functional safety",
      "properties": {
        "id": "topic-hvsafety",
        "name": "High-voltage and functional safety",
        "lede": "Keeping people safe from the pack’s voltage and keeping its electronics safe when they fail: insulation, switching, fusing and the functional-safety process.",
        "context": "Relate protection to faults, detection and response.",
        "example": "Normal-operation current limits do not demonstrate correct contactor behavior under a welded-contact or sensor fault.",
        "lesson_url": "https://lemonergy.com/learn/fundamentals/battery-basics/",
        "lesson_label": "Open battery basics"
      }
    },
    {
      "id": "term:voltage-class",
      "type": "Term",
      "label": "Voltage class",
      "properties": {
        "id": "voltage-class",
        "name": "Voltage class",
        "aka": [
          "voltage class A",
          "voltage class B",
          "high-voltage threshold",
          "HV",
          "LV"
        ],
        "section": "topic-hvsafety",
        "definition": "The line between circuits that need high-voltage protection and those that do not. UN R100 calls a circuit high voltage above 60 V DC or 30 V AC rms, up to 1500 V DC or 1000 V AC; ISO 6469-3 calls the same band voltage class B and anything lower class A. A 48 V system stays below the line.",
        "related": [
          "pack-voltage",
          "48v-system",
          "extra-low-voltage",
          "un-r100",
          "iso-6469",
          "high-voltage-interlock"
        ],
        "url": "https://lemonergy.com/learn/glossary/voltage-class/",
        "mentions": []
      }
    },
    {
      "id": "term:insulation-resistance",
      "type": "Term",
      "label": "Insulation resistance",
      "properties": {
        "id": "insulation-resistance",
        "name": "Insulation resistance",
        "aka": [
          "isolation resistance",
          "IMD"
        ],
        "section": "topic-hvsafety",
        "definition": "The resistance between the high-voltage circuit and the vehicle chassis, which must stay above about 100 Ω per volt of pack voltage so a person touching the chassis is safe. An insulation monitoring device measures it continuously.",
        "unit": "Ω/V",
        "related": [
          "pack-voltage",
          "high-voltage-interlock",
          "functional-safety",
          "insulation-test"
        ],
        "url": "https://lemonergy.com/learn/glossary/insulation-resistance/",
        "mentions": [
          "volt"
        ]
      }
    },
    {
      "id": "term:equipotential-bonding",
      "type": "Term",
      "label": "Equipotential bonding",
      "properties": {
        "id": "equipotential-bonding",
        "name": "Equipotential bonding",
        "aka": [
          "potential equalisation",
          "earth bonding",
          "chassis bonding",
          "bonding impedance"
        ],
        "section": "topic-hvsafety",
        "definition": "Connecting every exposed metal part — pack enclosure, motor frame, charger case — firmly to the chassis so that none can sit at a different voltage after an insulation fault. UN R100 requires under 0.1 Ω between exposed conductive parts and the chassis, measured with at least 0.2 A; during conductive charging the chassis is also tied to protective earth.",
        "related": [
          "insulation-fault",
          "insulation-resistance",
          "un-r100",
          "enclosure",
          "extra-low-voltage"
        ],
        "url": "https://lemonergy.com/learn/glossary/equipotential-bonding/",
        "mentions": [
          "charger"
        ]
      }
    },
    {
      "id": "term:48v-system",
      "type": "Term",
      "label": "48 V system",
      "properties": {
        "id": "48v-system",
        "name": "48 V system",
        "aka": [
          "mild hybrid"
        ],
        "section": "topic-applications",
        "definition": "A vehicle electrical architecture at 48 V, used for mild hybrids and heavy accessories. It stays below the 60 V threshold at which high-voltage safety rules begin, so it needs no orange cables or interlocks.",
        "related": [
          "hybrid-vehicle",
          "auxiliary-battery",
          "pack-voltage",
          "24v-system"
        ],
        "url": "https://lemonergy.com/learn/glossary/48v-system/",
        "mentions": []
      }
    }
  ]
}