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Leipole Electric

Screw Terminal Blocks

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Overview

Our IEC screw terminal blocks comply with recognized international IEC standards. Our finger-proof terminals are designed for DIN rail mounting.

  • Screw-fixed design: Ensures secure wiring to prevent loosening or falling off.
  • Multiple specifications: Supports cables of different wire diameters and adapts to a variety of application scenarios.
  • High-temperature resistant materials: Adapt to high-temperature environments, improve safety and durability.
  • Clear identification: Equipped with terminal markings for easy wiring identification and maintenance.
  • Anti-vibration performance: Optimized structural design, suitable for high-vibration environments.

Key advantages

  • Gas‑Tight Metal‑to‑Metal Connection – Screw clamping creates a gas‑tight joint that resists oxidation, ensuring long‑term conductivity even in harsh environments.

  • High Torque Retention – Engineered threads and captive screws maintain clamping force under vibration and thermal cycling, preventing loosening over time.

  • Wide Conductor Compatibility – Accepts solid, stranded, or ferruled wires without special preparation, supporting flexible installation.

  • Thermal & Electrical Robustness – Rated for high current and temperature endurance, suitable for industrial power distribution and control circuits.

  • Multiple Wire Entry Options – Dual or multi‑conductor terminals simplify parallel connections and reduce panel space usage.

Models & specifications

JUK Screw Terminal Blocks

wdt_ID wdt_created_by wdt_created_at wdt_last_edited_by wdt_last_edited_at model size rated current rated voltage solid cross section (min) solid cross section (max) stranded cross section(min) stranded cross section(max)
1 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 2.5B T6.2×H42×W42.5 32A 800V 0.2mm² 4mm² 0.2mm² 2.5mm²
2 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 2.5N T5.2×H42×W42.5 32A 800V 0.2mm² 4mm² 0.2mm² 2.5mm²
3 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 3N T5.2×H47×W42.5 32A 800V 0.2mm² 4mm² 0.2mm² 2.5mm²
4 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 5N T6.2×H47×W42.5 41A 800V 0.2mm² 6mm² 0.2mm² 4mm²
5 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 6N T8.2×H47×W42.5 57A 800V 0.2mm² 10mm² 0.2mm² 6mm²
6 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 10N T10.2×H47×W42.5 76A 800V 0.5mm² 16mm² 0.5mm² 10mm²
7 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 16N T12.2×H54×W42.5 100A 800V 2.5mm² 25mm² 4mm² 16mm²
8 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUK 35N T15.2×H62×W55 125A 800V 10mm² 35mm² 10mm² 35mm²
9 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUKH 50 T20×H83.5×W70.5 150A 1000V 16mm² 50mm² 25mm² 50mm²
10 Kiva 04/08/2025 05:36 AM Kiva 04/08/2025 05:36 AM JUKH 95 T25×H91×W83.9 232A 1000V 25mm² 95mm² 35mm² 95mm²

All 8 model pages

Applications

  • Industrial Control Panels – Securely connect power, control, and signal wiring for PLCs, relays, and automation components.

  • Power Distribution Boards – Distribute mains or low‑voltage power safely within machinery, switchgear, and electrical cabinets.

  • Building Electrical Systems – Provide durable wiring connections for lighting circuits, HVAC systems, and fire‑alarm panels.

  • Transportation & Rail Systems – Maintain vibration‑resistant electrical connections in rolling stock, signaling, and trackside control.

  • Energy & Utility Equipment – Connect metering devices, circuit breakers, and transformer secondary wiring in substations.

  • Marine & Offshore Installations – Resist corrosion and maintain conductivity in shipboard electrical systems and offshore platforms.

  • Renewable Energy Systems – Facilitate solar PV array wiring, wind turbine control systems, and battery‑storage interconnections.

  • Test & Measurement Racks – Enable quick wiring changes and secure connections for laboratory and field testing setups.

Basic knowledge

1. Gas‑Tight Connections Extend Service Life

When correctly torqued, the screw compresses the conductor against a plated copper alloy contact, forming a gas‑tight metal‑to‑metal bond. This prevents micro‑oxidation at the contact surface—one of the leading causes of hidden electrical resistance over time.

2. Torque Accuracy is Critical

Over‑tightening can damage conductor strands or deform ferrules; under‑tightening leads to vibration‑induced loosening. Torque‑limiting screwdrivers are standard in high‑reliability sectors such as rail, aerospace, and energy distribution to ensure repeatable, optimal clamping force.

3. Vibration & Thermal Cycling Resistance

High‑quality screw terminal blocks use spring‑loaded pressure plates or anti‑vibration thread designs to maintain clamping force through thousands of thermal expansion/contraction cycles, preventing creep and loosening in high‑current or high‑temperature applications.

Frequently asked questions

Why use screw terminal blocks in industrial control panels?

They provide secure, high‑current connections that withstand vibration, temperature cycling, and heavy‑duty industrial use.

What makes a 100A screw terminal block suitable for high‑current applications?

It uses heavy‑gauge conductive elements and large clamping surfaces to ensure minimal voltage drop and safe current handling.

When should I choose a PCB‑mount screw terminal block?

For direct integration into circuit boards, allowing secure wire‑to‑board connections without extra connectors or adapters.

Why choose DIN‑rail screw terminal blocks?

They simplify installation, enable modular expansion, and meet standardized sizing for electrical panel systems.

What are the benefits of multi‑level screw terminal blocks?

They allow multiple connection layers in the same footprint, saving space in dense control panel layouts.

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Selection & support

Selecting LEIPOLE screw terminal blocks

Match conductor size, current and voltage before confirming a terminal block.

Which screw terminal blocks does LEIPOLE supply?

The LEIPOLE JUK series runs from JUK 2.5 to JUK 35N, rated 32 to 125 A at 800 V, and the JUKH 50, JUKH 95, JUKH 150 and JUKH 240 take conductors up to 50, 95, 150 and 240 mm² at 150 A, 232 A, 309 A and 415 A, 1000 V. All mount on a 35 mm DIN rail.

Check technical documents

How do I choose a terminal block size?

Pick the block whose cross-section range covers the conductor and whose rated current exceeds the circuit current: for example JUK 2.5N takes 0.2 to 4 mm² solid wire at 32 A and JUK 10N 0.5 to 16 mm² at 76 A. Choose screw clamps where installers torque each wire, and spring clamps for vibration and fast wiring.

Compare spring terminals

How do screw terminal blocks compare with spring and barrier terminal blocks?

Screw blocks clamp each conductor under a screw tightened to a set torque, which suits heavy feeders and installers who torque every wire. LEIPOLE JST spring blocks wire faster and need no retightening, but stop at 10 mm² and 52 A. UN barrier blocks also clamp with screws and put a molded PA66 wall between poles. The terminal block page compares all four types.

Compare terminal block types