{
  "node": {
    "id": "term:creepage-distance",
    "type": "Term",
    "label": "Creepage distance",
    "properties": {
      "id": "creepage-distance",
      "name": "Creepage distance",
      "aka": [
        "creepage",
        "surface distance"
      ],
      "section": "topic-hvsafety",
      "definition": "The shortest path between two conductors measured along the surface of the insulation between them. Moisture and dirt on that surface can carry leakage current and tracking, so the required distance grows with working voltage, pollution and a poorer tracking index: at 400 V and pollution degree 2, basic insulation needs about 2 mm on a group I material but 4 mm on group III.",
      "related": [
        "clearance",
        "comparative-tracking-index",
        "electrical-breakdown",
        "voltage-class",
        "insulation-resistance"
      ],
      "url": "https://lemonergy.com/learn/glossary/creepage-distance/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:5042",
      "source": "term:creepage-distance",
      "target": "topic:topic-hvsafety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5043",
      "source": "term:creepage-distance",
      "target": "term:clearance",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5044",
      "source": "term:creepage-distance",
      "target": "term:comparative-tracking-index",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5045",
      "source": "term:creepage-distance",
      "target": "term:electrical-breakdown",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5046",
      "source": "term:creepage-distance",
      "target": "term:voltage-class",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5047",
      "source": "term:creepage-distance",
      "target": "term:insulation-resistance",
      "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:clearance",
      "type": "Term",
      "label": "Clearance",
      "properties": {
        "id": "clearance",
        "name": "Clearance",
        "aka": [
          "clearance distance",
          "air gap"
        ],
        "section": "topic-hvsafety",
        "definition": "The shortest distance through air between two conductive parts at different potentials. It is sized for the highest transient voltage the insulation must withstand, since air breaks down at roughly 3 kV/mm, and must grow above 2000 m altitude where thinner air breaks down sooner. IEC 60664-1 sets the values for most electronics.",
        "related": [
          "creepage-distance",
          "electrical-breakdown",
          "voltage-class",
          "comparative-tracking-index",
          "insulation-test"
        ],
        "url": "https://lemonergy.com/learn/glossary/clearance/",
        "mentions": []
      }
    },
    {
      "id": "term:comparative-tracking-index",
      "type": "Term",
      "label": "Comparative tracking index",
      "properties": {
        "id": "comparative-tracking-index",
        "name": "Comparative tracking index",
        "abbr": "CTI",
        "aka": [
          "tracking resistance"
        ],
        "section": "topic-hvsafety",
        "definition": "The highest voltage at which an insulating material survives 50 drops of a conductive ammonium chloride solution without forming a carbonised track, tested to IEC 60112. Materials fall in groups from I (CTI ≥ 600) to IIIb (100–175); a better group permits shorter creepage distances, which matters for compact 800 V busbar holders and circuit boards.",
        "unit": "V",
        "related": [
          "creepage-distance",
          "clearance",
          "electrical-breakdown",
          "voltage-class",
          "iec-60112"
        ],
        "url": "https://lemonergy.com/learn/glossary/comparative-tracking-index/",
        "mentions": [
          "busbar"
        ]
      }
    },
    {
      "id": "term:electrical-breakdown",
      "type": "Term",
      "label": "Electrical breakdown",
      "properties": {
        "id": "electrical-breakdown",
        "name": "Electrical breakdown",
        "aka": [
          "dielectric breakdown",
          "breakdown voltage",
          "dielectric strength"
        ],
        "section": "topic-hvsafety",
        "definition": "The sudden failure of an insulator to block current once the electric field exceeds its dielectric strength, about 3 kV/mm for air at sea level and far higher for solid films. In 800 V drives, partial discharges in voids, driven by fast inverter switching edges, can erode insulation until it fails at normal voltage.",
        "related": [
          "clearance",
          "insulation-resistance",
          "insulation-test",
          "arcing",
          "creepage-distance"
        ],
        "url": "https://lemonergy.com/learn/glossary/electrical-breakdown/",
        "mentions": [
          "inverter"
        ]
      }
    },
    {
      "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"
        ]
      }
    }
  ]
}