{
  "node": {
    "id": "term:contactor-arc-suppression",
    "type": "Term",
    "label": "Contactor arc suppression",
    "properties": {
      "id": "contactor-arc-suppression",
      "name": "Contactor arc suppression",
      "aka": [
        "magnetic blow-out",
        "arc quenching",
        "arc chute",
        "gas-filled contactor"
      ],
      "section": "topic-hvsafety",
      "definition": "The means by which a high-voltage DC contactor breaks current under load. Permanent magnets push the arc sideways to stretch and cool it — so many contactors are polarised and break less current in reverse — and hermetically sealed chambers filled with hydrogen or hydrogen–nitrogen gas cool the arc and keep the contacts clean.",
      "related": [
        "contactor",
        "arcing",
        "contactor-weld-detection",
        "battery-disconnect-unit",
        "pyrofuse"
      ],
      "url": "https://lemonergy.com/learn/glossary/contactor-arc-suppression/",
      "mentions": []
    }
  },
  "edges": [
    {
      "id": "edge:5075",
      "source": "term:contactor-arc-suppression",
      "target": "topic:topic-hvsafety",
      "type": "belongsTo",
      "properties": {
        "sourceFile": "terms.json"
      }
    },
    {
      "id": "edge:5076",
      "source": "term:contactor-arc-suppression",
      "target": "term:contactor",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5077",
      "source": "term:contactor-arc-suppression",
      "target": "term:arcing",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5078",
      "source": "term:contactor-arc-suppression",
      "target": "term:contactor-weld-detection",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5079",
      "source": "term:contactor-arc-suppression",
      "target": "term:battery-disconnect-unit",
      "type": "relatedTo",
      "properties": {
        "sourceFile": "terms.json",
        "meaning": "Related context; not a causal claim"
      }
    },
    {
      "id": "edge:5080",
      "source": "term:contactor-arc-suppression",
      "target": "term:pyrofuse",
      "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:contactor",
      "type": "Term",
      "label": "Contactor",
      "properties": {
        "id": "contactor",
        "name": "Contactor",
        "section": "topic-hvsafety",
        "definition": "A heavy-duty electrically operated switch that connects the pack to the vehicle or inverter and opens it on fault or shutdown. Packs use at least two, one per pole, plus a pre-charge path to avoid welding them on the first connection.",
        "related": [
          "pre-charge",
          "battery-disconnect-unit",
          "pyrofuse",
          "bms"
        ],
        "url": "https://lemonergy.com/learn/glossary/contactor/",
        "mentions": [
          "inverter"
        ]
      }
    },
    {
      "id": "term:arcing",
      "type": "Term",
      "label": "Arcing",
      "properties": {
        "id": "arcing",
        "name": "Arcing",
        "aka": [
          "electric arc",
          "DC arc"
        ],
        "section": "topic-hvsafety",
        "definition": "Current continuing through ionised gas across a gap, typically between contacts as they separate. An AC arc goes out by itself at each current zero, a hundred times a second at 50 Hz; a DC arc has no zero and keeps burning until it is stretched and cooled so far that its voltage exceeds the source’s, which makes high-voltage DC far harder to interrupt.",
        "related": [
          "contactor-arc-suppression",
          "arc-flash",
          "contactor",
          "fuse",
          "direct-current",
          "electrical-breakdown"
        ],
        "url": "https://lemonergy.com/learn/glossary/arcing/",
        "mentions": []
      }
    },
    {
      "id": "term:contactor-weld-detection",
      "type": "Term",
      "label": "Contactor weld detection",
      "properties": {
        "id": "contactor-weld-detection",
        "name": "Contactor weld detection",
        "aka": [
          "welded contactor",
          "stuck contactor diagnostic",
          "contactor diagnostics"
        ],
        "section": "topic-hvsafety",
        "definition": "A diagnostic that checks a contactor really opened when told to. The BMS compares voltages on each side of each contactor — if the load side still shows pack voltage after opening, the contacts have welded — or reads mirror auxiliary contacts. A welded contactor is latched as a fault, because the pack can no longer be fully disconnected.",
        "related": [
          "contactor",
          "pre-charge",
          "battery-disconnect-unit",
          "dtc",
          "contactor-arc-suppression"
        ],
        "url": "https://lemonergy.com/learn/glossary/contactor-weld-detection/",
        "mentions": [
          "pack-voltage",
          "bms"
        ]
      }
    },
    {
      "id": "term:battery-disconnect-unit",
      "type": "Term",
      "label": "Battery disconnect unit",
      "properties": {
        "id": "battery-disconnect-unit",
        "name": "Battery disconnect unit",
        "abbr": "BDU",
        "aka": [
          "battery junction box"
        ],
        "section": "topic-hvsafety",
        "definition": "The box inside the pack that holds the contactors, pre-charge circuit, main fuse or pyrofuse and current sensor, where the pack’s high-voltage connections are made and broken.",
        "related": [
          "contactor",
          "pre-charge",
          "fuse",
          "pyrofuse",
          "current-sensor"
        ],
        "url": "https://lemonergy.com/learn/glossary/battery-disconnect-unit/",
        "mentions": []
      }
    },
    {
      "id": "term:pyrofuse",
      "type": "Term",
      "label": "Pyrofuse",
      "properties": {
        "id": "pyrofuse",
        "name": "Pyrofuse",
        "aka": [
          "pyrotechnic disconnect"
        ],
        "section": "topic-hvsafety",
        "definition": "A high-voltage disconnect fired by a small pyrotechnic charge on command, typically from the airbag controller in a crash. It cuts the pack from the vehicle in milliseconds, faster and more reliably than a contactor can open under fault current.",
        "related": [
          "fuse",
          "contactor",
          "battery-disconnect-unit",
          "high-voltage-interlock"
        ],
        "url": "https://lemonergy.com/learn/glossary/pyrofuse/",
        "mentions": []
      }
    }
  ]
}