{
  "node": {
    "id": "term:insulation-fault",
    "type": "Term",
    "label": "Insulation fault",
    "properties": {
      "id": "insulation-fault",
      "name": "Insulation fault",
      "aka": [
        "ground fault",
        "earth fault",
        "isolation fault",
        "chassis fault"
      ],
      "section": "topic-hvsafety",
      "definition": "An unintended low-resistance path between a high-voltage conductor and the chassis, from damaged insulation, coolant leaks or moisture. A vehicle’s high-voltage system floats free of the chassis, so a single fault drives no current; a second on the other pole completes a circuit through the chassis. The insulation monitor therefore flags the first before a second can arise.",
      "related": [
        "insulation-resistance",
        "insulation-test",
        "equipotential-bonding",
        "dtc",
        "voltage-class"
      ],
      "url": "https://lemonergy.com/learn/glossary/insulation-fault/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:5114",
      "source": "term:insulation-fault",
      "target": "topic:topic-hvsafety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5115",
      "source": "term:insulation-fault",
      "target": "term:insulation-resistance",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5116",
      "source": "term:insulation-fault",
      "target": "term:insulation-test",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5117",
      "source": "term:insulation-fault",
      "target": "term:equipotential-bonding",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5118",
      "source": "term:insulation-fault",
      "target": "term:dtc",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5119",
      "source": "term:insulation-fault",
      "target": "term:voltage-class",
      "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: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:insulation-test",
      "type": "Term",
      "label": "Insulation resistance test",
      "properties": {
        "id": "insulation-test",
        "name": "Insulation resistance test",
        "aka": [
          "hipot test",
          "dielectric strength test"
        ],
        "section": "topic-testing",
        "definition": "Applying a high DC or AC voltage between the high-voltage circuit and the chassis or housing to verify that insulation holds, with the leakage current below a limit. It is done on every pack at end of line and after abuse tests in R100.",
        "related": [
          "insulation-resistance",
          "un-r100-part-2",
          "high-voltage-interlock",
          "end-of-line-testing"
        ],
        "url": "https://lemonergy.com/learn/glossary/insulation-test/",
        "mentions": [
          "un-r100"
        ]
      }
    },
    {
      "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:dtc",
      "type": "Term",
      "label": "Diagnostic trouble code",
      "properties": {
        "id": "dtc",
        "name": "Diagnostic trouble code",
        "abbr": "DTC",
        "aka": [
          "fault code"
        ],
        "section": "topic-data",
        "definition": "A coded fault a controller stores when a check fails — a cell overvoltage, a sensor out of range, an isolation fault — with a status and often a snapshot of conditions when it occurred. Reading and interpreting DTCs is the first step of any battery root-cause analysis.",
        "related": [
          "uds",
          "bmu",
          "insulation-resistance",
          "freeze-frame"
        ],
        "url": "https://lemonergy.com/learn/glossary/dtc/",
        "mentions": [
          "insulation-fault"
        ]
      }
    },
    {
      "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": []
      }
    }
  ]
}