What Electrical Faults Will Be Caused by Unqualified Crimping of SC (JGK) Inspection Hole Copper Lugs?

In low-voltage distribution panels, industrial automation control cabinets, photovoltaic energy storage systems, and rail transit vehicles, SC(JGK) inspection hole copper lugs are basic power connection fittings for reliable conduction between cables and electrical equipment. This series is made of T2 high-purity purple copper with 99.9% purity, surface-treated with tin for corrosion protection, adapting to copper conductors with cross-sections of 1.5-1000mm2, and working temperatures from -55°C to 150°C, meeting most harsh industrial requirements. However, in many engineering practices, electrical faults are often not caused by terminal quality defects but by non-standard on-site crimping construction and unqualified quality.

Local overheating caused by insufficient crimping depth is a common fault type. The SC(JGK) series has an inspection hole structure, primarily for construction personnel to visually confirm the wire core is fully inserted into the crimping barrel. If the insertion length is insufficient, with only a few conductors at the front in contact with the inner wall, the effective conductive cross-section will be significantly reduced, leading to a marked increase in contact resistance. When the equipment runs at full load, abnormal high temperature will be generated at the contact point, accelerating cable insulation aging and terminal tin-layer oxidation, causing abnormal tripping or even ignition of surrounding materials and electrical fires.

Insufficient crimping tightness leads to intermittent connection failure under high vibration. When crimping tool tonnage is mismatched or die specifications deviate, the gripping force between terminal and cable fails to meet design requirements, leaving tiny gaps. In scenarios like engineering machinery and rail transit with continuous vibration, cables are repeatedly affected by pull and vibration, causing the contact surface to oxidize into a high-impedance layer, resulting in intermittent power failure. This not only damages expensive electrical components like frequency converters and servo motors but also causes unplanned downtime and direct production losses.

Over-crimping causes structural damage to the conductor and terminal body. Excessive force or wrong die selection can crack the crimping barrel or even cut internal multi-strand copper wires, directly weakening rated current-carrying capacity. Meanwhile, the protective tin layer on the surface will be damaged due to extrusion, losing its anti-corrosion function. In humid or salt spray environments, exposed copper substrate will corrode quickly, with contact resistance rising continuously, potentially leading to short circuits or open circuits.

Inadequate pre-treatment of wire cores before construction also hides faults. Residual insulation debris, scattered strands, or oil stains on the core surface will isolate conductors from the inner wall, forming high-resistance contact surfaces even if the crimping itself is standard. These faults are hard to troubleshoot initially, but long-term operation will lead to insulation breakdown and grounding or short-circuit faults, representing major safety risks in outdoor distribution and PV plants.

To avoid these faults, a standardized crimping process must be established: match SC(JGK) terminals to cable sections; control stripping length to ensure the core enters the visual area of the inspection hole; use calibrated crimping tools and matching dies; re-check insertion depth via the hole after crimping and conduct pull tests to verify connection strength. High-quality terminal substrate is the foundation of reliability, but standardized construction is necessary to fully exploit the performance advantages of T2 purple copper tin-plated terminals in high conductivity, wide temperature range, and corrosion resistance, reducing life-cycle O&M risks.

Hubei HOORED Electric Co., Ltd. is a manufacturer with core competitiveness in the field of wires and cables, integrating R&D, manufacturing, trade, and service. Product categories include: terminal blocks, power fittings, quick connectors, waterproof joints, cable ties, wire ducts, etc. For more information about SC(JGK) inspection hole copper lug, welcome to call for consultation.

Email: info@hooyeegroup.com, cinderella@hooyeegroup.com

WhatsApp: +86 138 0660 7069, +86 189 5881 2001

Tel: 86-577-62190012, 62190013, 62033001

Website: https://www.hooyeegroup.com/

Headquarters Address: Zhucheng Avenue, Yuwang High-tech Zone Industrial Park, Huangzhou District, Huanggang City, Hubei Province

Branch Address: No. 13, Tengfei Road, Dongfeng Industrial Zone, Liushi Town, Yueqing, Wenzhou, Zhejiang Province