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mine load centre feeder

9 Min Read
The Grasberg copper-gold mine in Indonesia, operated by PT Freeport Indonesia, is one of the world's largest and most technically complex hard rock mining operations. In recent years, the operation has transitioned to block cave mining (caving by gravity) to achieve depth-efficient extraction of ore from depths exceeding 1,000 meters. This transition creates unprecedented electrical infrastructure demands. 印尼自由港公司(PT Freeport Indonesia)运营的格拉斯伯格铜金矿是全球最大、技术最复杂的硬岩矿山之一。近年来，该矿区已过渡到自然崩落法(通过重力采矿)，以实现深度超过1000米的矿石的深度高效开采。这一转变对电气基础设施提出了前所未有的要求。 Operational Context: Block cave mining requires large mobile substations, underground primary crushers, and heavy-duty drilling equipment (drill jumbos) to be positioned and repositioned continuously throughout the deep mine workings. Each of these installations demands flexible high-voltage power distribution cables capable of surviving: (1) Acidic sulfide-rich groundwater exposure, (2) Extreme mechanical abrasion from sharp porphyry rock fragments, (3) Continuous flexing and reeling during equipment repositioning, (4) High-voltage electrical stress at 11kV.
Technical Department
on06/03/2026

Grasberg Block Cave: Sourcing AS/NZS 1802 Type 241 11/11kV 3x95mm² for Indonesia Copper Mines

The Grasberg copper-gold mine in Indonesia, operated by PT Freeport Indonesia, is one of the world’s largest and most technically complex hard rock mining operations. In recent years, the operation has transitioned to block cave mining (caving by gravity) to achieve depth-efficient extraction of ore from depths exceeding 1,000 meters. This transition creates unprecedented electrical infrastructure demands. 印尼自由港公司(PT Freeport Indonesia)运营的格拉斯伯格铜金矿是全球最大、技术最复杂的硬岩矿山之一。近年来，该矿区已过渡到自然崩落法(通过重力采矿)，以实现深度超过1000米的矿石的深度高效开采。这一转变对电气基础设施提出了前所未有的要求。 Operational Context: Block cave mining requires large mobile substations, underground primary crushers, and heavy-duty drilling equipment (drill jumbos) to be positioned and repositioned continuously throughout the deep mine workings. Each of these installations demands flexible high-voltage power distribution cables capable of surviving: (1) Acidic sulfide-rich groundwater exposure, (2) Extreme mechanical abrasion from sharp porphyry rock fragments, (3) Continuous flexing and reeling during equipment repositioning, (4) High-voltage electrical stress at 11kV.
9 Min Read
Standards Clarification: AS/NZS 1972 defines Type 9 explicitly as a gas non-transmission cable, specifically engineered for flameproof (Ex d) electrical equipment enclosures. Type 9 cables are typically small-diameter, multi-core control or monitoring cables (0.5 mm², 1.5 mm², etc.)—never large power conductors like 3×95 mm². 标准澄清：AS/NZS 1972明确定义Type 9为防气体传输电缆，特别是为了防爆(Ex d)电气设备外壳而设计。Type 9电缆通常是小径、多芯的控制或监测电缆(0.5 mm²、1.5 mm²等)——绝对不是大功率导体如3×95 mm²。 Why the Confusion? The numbering system in AS/NZS 1972 progresses from Type 1 (fixed installation) through Type 8 (vertical shaft DWA cables). Type 9's designation comes last but reflects a specialized application (flameproof enclosures) rather than advancement in power capacity. Engineers sometimes assume higher type numbers equal higher voltage/current capacity—this assumption is incorrect for Type 9.
Technical Department
on06/03/2026

Tensile Load Limits: Calculating Maximum Suspension Depth for AS/NZS 1972 Mining Cables

Standards Clarification: AS/NZS 1972 defines Type 9 explicitly as a gas non-transmission cable, specifically engineered for flameproof (Ex d) electrical equipment enclosures. Type 9 cables are typically small-diameter, multi-core control or monitoring cables (0.5 mm², 1.5 mm², etc.)—never large power conductors like 3×95 mm². 标准澄清：AS/NZS 1972明确定义Type 9为防气体传输电缆，特别是为了防爆(Ex d)电气设备外壳而设计。Type 9电缆通常是小径、多芯的控制或监测电缆(0.5 mm²、1.5 mm²等)——绝对不是大功率导体如3×95 mm²。 Why the Confusion? The numbering system in AS/NZS 1972 progresses from Type 1 (fixed installation) through Type 8 (vertical shaft DWA cables). Type 9’s designation comes last but reflects a specialized application (flameproof enclosures) rather than advancement in power capacity. Engineers sometimes assume higher type numbers equal higher voltage/current capacity—this assumption is incorrect for Type 9.Standards Clarification: AS/NZS 1972 defines Type 9 explicitly as a gas non-transmission cable, specifically engineered for flameproof (Ex d) electrical equipment enclosures. Type 9 cables are typically small-diameter, multi-core control or monitoring cables (0.5 mm², 1.5 mm², etc.)—never large power conductors like 3×95 mm². 标准澄清：AS/NZS 1972明确定义Type 9为防气体传输电缆，特别是为了防爆(Ex d)电气设备外壳而设计。Type 9电缆通常是小径、多芯的控制或监测电缆(0.5 mm²、1.5 mm²等)——绝对不是大功率导体如3×95 mm²。 Why the Confusion? The numbering system in AS/NZS 1972 progresses from Type 1 (fixed installation) through Type 8 (vertical shaft DWA cables). Type 9’s designation comes last but reflects a specialized application (flameproof enclosures) rather than advancement in power capacity. Engineers sometimes assume higher type numbers equal higher voltage/current capacity—this assumption is incorrect for Type 9.
19 Min Read
For a Type 3S 11kV feeder cable with 82–88 mm outer diameter (typically a 3x95mm² to 3x240mm² conductor), the appropriate Ex d cable gland must be sized to accommodate the cable's full outer diameter while maintaining the flange-threaded sealing design required by ATEX EN 60079-1 for Zone 1 explosive atmospheres. A typical selection for a 3x95mm² Type 3S cable would be an M100 or M105 flange-threaded gland rated for ATEX II 2G Ex d IIB T4, with a compressive sealing ring (typically 2 mm thick polyurethane or equivalent elastomer) that creates a pressure-tight barrier against explosive gas ingress, and a separate earthing screw or braided conductor that bonds the cable's steel wire armor directly to the enclosure's earth continuity. This is not simply a matter of finding any cable gland that fits the cable diameter—it is a critical safety component that must be certified, specified, and installed with precision.
Technical Department
on06/03/2026

Ex d Gland Matching: Terminating Type 3S 11kV SWA Armor in Hazardous Zone 1

For a Type 3S 11kV feeder cable with 82–88 mm outer diameter (typically a 3x95mm² to 3x240mm² conductor), the appropriate Ex d cable gland must be sized to accommodate the cable’s full outer diameter while maintaining the flange-threaded sealing design required by ATEX EN 60079-1 for Zone 1 explosive atmospheres. A typical selection for a 3x95mm² Type 3S cable would be an M100 or M105 flange-threaded gland rated for ATEX II 2G Ex d IIB T4, with a compressive sealing ring (typically 2 mm thick polyurethane or equivalent elastomer) that creates a pressure-tight barrier against explosive gas ingress, and a separate earthing screw or braided conductor that bonds the cable’s steel wire armor directly to the enclosure’s earth continuity. This is not simply a matter of finding any cable gland that fits the cable diameter—it is a critical safety component that must be certified, specified, and installed with precision.