{
 "description": "Annex I.4: cases wired as clause 6.1 and 6.3 ask, every conductor with its gauge and length. tools/distribution.py computes each conductor's resistance from data/power_interfaces.json row_wiring (solid copper × the strand factor, plus a termination at each end), its drop at the current it carries, and checks it against PWR-006, PWR-007 (5 mΩ), ASM-009 (2 mΩ links), PWR-008 (bonds), and the two rings a terminal takes.",
 "examples": [
  {
   "id": "one-row",
   "title": "One row from a DC adapter",
   "case": "A 3U, 84 HP desktop case in wood with anodized rails and steel M3 strips. A 12 V, 5 A desktop adapter plugs into a DC-DIN4 case DC entry panel at the left end of the row; a 48 W-class supply (2.6 A on +12 V, 1.0 A on −12 V, 1.0 A on +5 V) sits behind the row beside the entry; one bus board runs the row, its inlet terminals at mid-row.",
   "tie": "The DC entry panel bonds 0 V to its panel through a 0 Ω link and carries the M4 CHASSIS stud; the case is wood and the rails anodized, so the chassis is the steel strips and whatever panels are bare under their screw heads, and no strap is needed (6.3). The adapter floats.",
   "conductors": [
    {
     "name": "entry +12 V to supply +12 V in",
     "from": "entry.+12V",
     "to": "psu.+12V_in",
     "amps": 5.0,
     "awg": 16,
     "length_mm": 150,
     "kind": "row"
    },
    {
     "name": "entry 0 V to supply 0 V in",
     "from": "entry.0V",
     "to": "psu.0V_in",
     "amps": 5.0,
     "awg": 16,
     "length_mm": 150,
     "kind": "row"
    },
    {
     "name": "supply +12 V to bus board +12 V",
     "from": "psu.+12V",
     "to": "board.+12V",
     "amps": 2.6,
     "awg": 16,
     "length_mm": 300,
     "kind": "row",
     "alternative_awg": 18
    },
    {
     "name": "supply −12 V to bus board −12 V",
     "from": "psu.-12V",
     "to": "board.-12V",
     "amps": 1.0,
     "awg": 16,
     "length_mm": 300,
     "kind": "row"
    },
    {
     "name": "supply +5 V to bus board +5 V",
     "from": "psu.+5V",
     "to": "board.+5V",
     "amps": 1.0,
     "awg": 16,
     "length_mm": 300,
     "kind": "row"
    },
    {
     "name": "supply 0 V to bus board 0 V",
     "from": "psu.0V",
     "to": "board.0V",
     "amps": 3.6,
     "awg": 16,
     "length_mm": 300,
     "kind": "row",
     "zero_v_of": [
      "supply +12 V to bus board +12 V",
      "supply −12 V to bus board −12 V",
      "supply +5 V to bus board +5 V"
     ]
    }
   ],
   "notes": [
    "One gauge for the whole case: 16 AWG, 1.5 mm² silicone, with red, blue, yellow, and black insulation for +12 V, −12 V, +5 V, and 0 V, and a 22 to 16 AWG ring terminal at every end.",
    "The 0 V conductor to the bus board carries the three rails' return, 3.6 A at most, and is the same gauge as the rail conductors beside it (PWR-007).",
    "Every module hangs on a power ribbon of at most 400 mm (BUS-015); the row wiring ends at the bus board."
   ]
  },
  {
   "id": "two-rows",
   "title": "Two rows from one supply",
   "case": "A 6U, 104 HP case in powder-coated aluminum with bare pads where the rails meet its sides, so the sides, rails, and strips are one chassis (GND-005). A DC-DIN4 case DC entry at the left feeds a 100 W-class supply (6.0 A on +12 V, 2.5 A on −12 V, 2.0 A on +5 V, 112 W out, about 11 A in at 85 % efficiency) mounted between the rows at the left end; each row has its own bus board with its inlet at mid-row, 250 mm from the supply for the upper row and 400 mm for the lower.",
   "tie": "The tie is the DC entry panel's CHASSIS stud. A strap from it to the nearest bare pad on the case side bonds the metalwork; the supply's 0 V is not bonded to the case anywhere else, and the supply publishes that.",
   "conductors": [
    {
     "name": "entry +12 V to supply +12 V in",
     "from": "entry.+12V",
     "to": "psu.+12V_in",
     "amps": 11.0,
     "awg": 12,
     "length_mm": 200,
     "kind": "row"
    },
    {
     "name": "entry 0 V to supply 0 V in",
     "from": "entry.0V",
     "to": "psu.0V_in",
     "amps": 11.0,
     "awg": 12,
     "length_mm": 200,
     "kind": "row"
    },
    {
     "name": "supply +12 V to upper board",
     "from": "psu.+12V",
     "to": "upper.+12V",
     "amps": 3.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row",
     "alternative_awg": 18
    },
    {
     "name": "supply −12 V to upper board",
     "from": "psu.-12V",
     "to": "upper.-12V",
     "amps": 1.25,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply +5 V to upper board",
     "from": "psu.+5V",
     "to": "upper.+5V",
     "amps": 1.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 0 V to upper board",
     "from": "psu.0V",
     "to": "upper.0V",
     "amps": 4.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row",
     "zero_v_of": [
      "supply +12 V to upper board",
      "supply −12 V to upper board",
      "supply +5 V to upper board"
     ]
    },
    {
     "name": "supply +12 V to lower board",
     "from": "psu.+12V",
     "to": "lower.+12V",
     "amps": 3.0,
     "awg": 14,
     "length_mm": 400,
     "kind": "row",
     "alternative_awg": 16
    },
    {
     "name": "supply −12 V to lower board",
     "from": "psu.-12V",
     "to": "lower.-12V",
     "amps": 1.25,
     "awg": 14,
     "length_mm": 400,
     "kind": "row"
    },
    {
     "name": "supply +5 V to lower board",
     "from": "psu.+5V",
     "to": "lower.+5V",
     "amps": 1.0,
     "awg": 14,
     "length_mm": 400,
     "kind": "row"
    },
    {
     "name": "supply 0 V to lower board",
     "from": "psu.0V",
     "to": "lower.0V",
     "amps": 4.0,
     "awg": 14,
     "length_mm": 400,
     "kind": "row",
     "zero_v_of": [
      "supply +12 V to lower board",
      "supply −12 V to lower board",
      "supply +5 V to lower board"
     ]
    },
    {
     "name": "0 V link, upper board to lower board",
     "from": "upper.0V",
     "to": "lower.0V",
     "amps": 0,
     "awg": 12,
     "length_mm": 180,
     "kind": "link"
    },
    {
     "name": "strap, CHASSIS stud to the case side",
     "from": "entry.CHASSIS",
     "to": "case.pad",
     "amps": 0,
     "awg": 14,
     "length_mm": 100,
     "kind": "bond"
    }
   ],
   "notes": [
    "The lower board's conductors are 14 AWG because of their length: 16 AWG over 400 mm would be over the 5 mΩ limit, as the table's alternative column shows.",
    "Each supply output terminal carries two ring terminals, one per board (6.1 recommends at most two); the +12 V terminal carries 6.0 A, within a 15 A terminal.",
    "The two boards hang on one supply, so ASM-009 does not require the link, but the two returns drop differently under load; the 12 AWG link holds the rows' references together for the cost of 180 mm of wire."
   ]
  },
  {
   "id": "two-supplies",
   "title": "Four rows from two supplies",
   "case": "A 12U, 104 HP case, four rows, two 100 W-class supplies, one DC-MF8 case DC entry rated 28 A at the left feeding both supplies in parallel, about 11 A each. Supply 1 sits between rows 1 and 2 and feeds their boards; supply 2 between rows 3 and 4 and feeds theirs. Each board's inlet is at mid-row, 250 mm from its supply.",
   "tie": "One tie, at the DC entry: its CHASSIS stud, strapped to the case side. Both supplies publish their 0 V as floating from the case. Row wiring returns run as two stars, one per supply; the links between the boards hold the four rows at one reference (ASM-009).",
   "conductors": [
    {
     "name": "entry +12 V to supply 1 +12 V in",
     "from": "entry.+12V",
     "to": "psu1.+12V_in",
     "amps": 11.0,
     "awg": 12,
     "length_mm": 150,
     "kind": "row"
    },
    {
     "name": "entry 0 V to supply 1 0 V in",
     "from": "entry.0V",
     "to": "psu1.0V_in",
     "amps": 11.0,
     "awg": 12,
     "length_mm": 150,
     "kind": "row"
    },
    {
     "name": "entry +12 V to supply 2 +12 V in",
     "from": "entry.+12V",
     "to": "psu2.+12V_in",
     "amps": 11.0,
     "awg": 12,
     "length_mm": 350,
     "kind": "row",
     "alternative_awg": 14
    },
    {
     "name": "entry 0 V to supply 2 0 V in",
     "from": "entry.0V",
     "to": "psu2.0V_in",
     "amps": 11.0,
     "awg": 12,
     "length_mm": 350,
     "kind": "row"
    },
    {
     "name": "supply 1 +12 V to board 1",
     "from": "psu1.+12V",
     "to": "b1.+12V",
     "amps": 3.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 1 0 V to board 1",
     "from": "psu1.0V",
     "to": "b1.0V",
     "amps": 4.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 1 +12 V to board 2",
     "from": "psu1.+12V",
     "to": "b2.+12V",
     "amps": 3.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 1 0 V to board 2",
     "from": "psu1.0V",
     "to": "b2.0V",
     "amps": 4.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 2 +12 V to board 3",
     "from": "psu2.+12V",
     "to": "b3.+12V",
     "amps": 3.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 2 0 V to board 3",
     "from": "psu2.0V",
     "to": "b3.0V",
     "amps": 4.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 2 +12 V to board 4",
     "from": "psu2.+12V",
     "to": "b4.+12V",
     "amps": 3.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "supply 2 0 V to board 4",
     "from": "psu2.0V",
     "to": "b4.0V",
     "amps": 4.0,
     "awg": 16,
     "length_mm": 250,
     "kind": "row"
    },
    {
     "name": "0 V link, board 1 to board 2",
     "from": "b1.0V",
     "to": "b2.0V",
     "amps": 0,
     "awg": 12,
     "length_mm": 180,
     "kind": "link"
    },
    {
     "name": "0 V link, board 2 to board 3 (the one ASM-009 requires)",
     "from": "b2.0V",
     "to": "b3.0V",
     "amps": 0,
     "awg": 12,
     "length_mm": 180,
     "kind": "link"
    },
    {
     "name": "0 V link, board 3 to board 4",
     "from": "b3.0V",
     "to": "b4.0V",
     "amps": 0,
     "awg": 12,
     "length_mm": 180,
     "kind": "link"
    },
    {
     "name": "strap, CHASSIS stud to the case side",
     "from": "entry.CHASSIS",
     "to": "case.pad",
     "amps": 0,
     "awg": 14,
     "length_mm": 100,
     "kind": "bond"
    }
   ],
   "notes": [
    "The −12 V and +5 V conductors of each board are left out of the table; they follow the +12 V ones at 16 AWG and 250 mm.",
    "The DC entry's +12 V and 0 V terminals each carry two ring terminals, one lead per supply, and 22 A in all, within a 30 A terminal and the entry's 28 A; a 15 A terminal would need one lead per stud, which is why a high-current entry carries two studs per pole.",
    "Boards 2 and 3 each take their return and two links on 0 V, three rings: a bus board's second M4 0 V position, or a 0 V strip with a bar (BUS-021), is where the third goes.",
    "A chain of three links satisfies ASM-009 here, since every board reaches a board of the other supply through them; a fourth link, board 1 to board 4, would make it a grid."
   ]
  },
  {
   "id": "rack-ac",
   "title": "A rack frame with an AC inlet",
   "case": "A zinc-plated steel 19-inch rack frame, 3U, 84 HP, with an AC inlet on its rear panel and a linear bus supply (2.0 A on +12 V, 2.0 A on −12 V, 1.0 A on +5 V) on the rear panel too, 350 mm from the bus board's inlet at mid-row. The frame's plated steel bonds at every bolt.",
   "tie": "The chassis is bonded to protective earth at the AC inlet, under the safety standard the supply is built to; 0 V meets the chassis at the supply's earth terminal, which the supply publishes (GND-003), on a strap to the frame. The DC side has no case DC entry, so there is no second tie.",
   "conductors": [
    {
     "name": "supply +12 V to bus board +12 V",
     "from": "psu.+12V",
     "to": "board.+12V",
     "amps": 2.0,
     "awg": 14,
     "length_mm": 350,
     "kind": "row",
     "alternative_awg": 16
    },
    {
     "name": "supply −12 V to bus board −12 V",
     "from": "psu.-12V",
     "to": "board.-12V",
     "amps": 2.0,
     "awg": 14,
     "length_mm": 350,
     "kind": "row"
    },
    {
     "name": "supply +5 V to bus board +5 V",
     "from": "psu.+5V",
     "to": "board.+5V",
     "amps": 1.0,
     "awg": 14,
     "length_mm": 350,
     "kind": "row"
    },
    {
     "name": "supply 0 V to bus board 0 V",
     "from": "psu.0V",
     "to": "board.0V",
     "amps": 3.0,
     "awg": 14,
     "length_mm": 350,
     "kind": "row",
     "zero_v_of": [
      "supply +12 V to bus board +12 V",
      "supply −12 V to bus board −12 V",
      "supply +5 V to bus board +5 V"
     ]
    },
    {
     "name": "bond, supply earth terminal to the frame",
     "from": "psu.EARTH",
     "to": "frame.pad",
     "amps": 0,
     "awg": 14,
     "length_mm": 80,
     "kind": "bond"
    }
   ],
   "notes": [
    "2 A on +12 V would allow 18 AWG by current, but 350 mm of 18 AWG is 8.2 mΩ and 16 AWG 5.3 mΩ; the length, not the current, sets 14 AWG here. Shorter leads, a supply nearer the inlet, would do the same with 16 AWG.",
    "The 0 V conductor carries 3.0 A at most, +12 V and +5 V returning together against −12 V's 2.0 A."
   ]
  },
  {
   "id": "two-cases",
   "title": "Two cases, each with its supply",
   "case": "Two desktop cases of the first example side by side, each with its own adapter, DC entry, supply, and bus board, patched together. Each case's bus board carries a second M4 0 V terminal for the link.",
   "tie": "Each case has its own tie at its DC entry; the adapters float, so the two ties make no loop. Each case has its own supply, so EIS recommends a 0 V link between the two bus boards (6.3): 10 AWG or heavier, as short as the cases allow, at most 2 mΩ where it can be. ASM-009's 2 mΩ binds inside one enclosure; three or more cases link as a grid.",
   "conductors": [
    {
     "name": "0 V link, case A bus board to case B bus board",
     "from": "a.0V",
     "to": "b.0V",
     "amps": 0,
     "awg": 10,
     "length_mm": 400,
     "kind": "link",
     "alternative_awg": 12,
     "between_cases": true
    }
   ],
   "notes": [
    "A 400 mm link on 10 AWG measures 1.9 mΩ, inside the 2 mΩ EIS recommends between cases; 12 AWG would reach only 270 mm, and past about 440 mm even 10 AWG cannot hold it, which is why the figure binds only inside a case. Hinton Instruments' ZeroVolt links between cases measure under 2 mΩ on heavy cable and high-current connectors.",
    "If the two cases shared one adapter through a case DC entry with two outlets, they would be one system with one tie; the supplies would still be two, so the link would still be wanted."
   ]
  }
 ]
}