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Leipole Electric

Spring Terminal Blocks

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Overview

Efficient spring terminal blocks, no screw operation, fast wiring, adapt to vibration and temperature difference environment.

  • Hook-blade connection technology: suitable for specific industrial applications, providing a more stable connection effect.
  • Quick and safe installation: after inserting the cable, the spring automatically fixes the conductor without additional operation.
  • Screw-free design: using the spring clamping structure, there is no need to tighten or loosen the screws, simplifying the wiring process.
  • Convenient operation: loosen the spring clamp with a flat screwdriver and easily push the wire into the terminal block.
  • Anti-vibration and temperature difference resistance: The spring clamping structure can resist vibration and temperature changes to ensure long-term stable connection.
  • Adapt to a variety of wire diameters: compatible with cables of different specifications, strong adaptability, and meet diverse needs.

Key advantages

  • Tool-Free Installation & Removal


    The spring-clamp system automatically grips conductors inserted into the terminal mouth. Wires can be added or removed by simply pressing the release lever—no screwdriver required.

  • Consistent Contact Pressure


    Stainless-steel spring elements maintain uniform clamping force over time and temperature cycles, preventing loose connections and reducing maintenance frequency.

  • High Vibration & Shock Resistance


    The dynamic spring mechanism absorbs vibration, ensuring contact reliability in machinery, transportation, and high-movement environments.

  • Wide Conductor Range


    JST terminals support 0.14 mm² to 10 mm² conductor cross-sections, handling both fine-stranded signal wires and medium-gauge power conductors.

  • Slim, Modular Design


    Compact housing footprints allow up to 20 % more terminal points per DIN rail compared to traditional screw-clamp blocks, optimizing cabinet real estate.

  • Enhanced Safety & Insulation


    Made from UL94 V-0 flame-retardant PA66, with reinforced barriers between poles, ensuring creepage and clearance distances meet high-voltage requirements up to 800 V AC/DC.

  • Integrated Marking & Bridging


    Each JST terminal features an easy-access marking slot for labels or printed markers, along with lateral and vertical bridge channels for quick circuit parallelization.

Models & specifications

LEIPOLE Spring Terminal Blocks JST4

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-max) stranded cross section (min-max)
48 Kiva 26/06/2025 08:43 AM Kiva 26/06/2025 08:43 AM JSTTB 2.5 (double layer） T5.2xH47.5xW68 26A 800V 0.2mm² - 4mm² 0.2mm² - 2.5mm²
53 Kiva 26/06/2025 08:44 AM Kiva 26/06/2025 08:45 AM JST 2.5-QU (four lead) T5.2xH36xW73 28A 800V 0.2mm² - 4mm² 0.2mm² -2.5mm²
54 Kiva 26/06/2025 08:49 AM Kiva 26/06/2025 08:49 AM JST1.5 T4.2 H36.5 W48.5 17.5A 500V 0.14mm² - 1.5mm² 0.14mm² -1.5mm²
55 Kiva 26/06/2025 08:50 AM Kiva 26/06/2025 08:50 AM JST 2.5 T5.2 H36.5 W48.5 31A 800V 0.14mm² - 1.5mm² 0.2mm² - 2.5mm²
56 Kiva 26/06/2025 08:50 AM Kiva 26/06/2025 08:50 AM JST 4 T6.2 H36.5 W56 40A 800V 0.2mm² - 6mm² 0.2mm² - 4mm²
57 Kiva 26/06/2025 08:51 AM Kiva 26/06/2025 08:51 AM JST 6 T8.2 H43.5 W69.5 52A 800V 0.5mm² - 10mm² 0.5mm² - 6mm²
58 Kiva 26/06/2025 08:52 AM Kiva 26/06/2025 08:52 AM JST 2.5-TW T5.2 H36 W71 28A* 800V 0.2mm² - 4mm² 0.2mm² - 2.5mm²
59 Kiva 26/06/2025 08:52 AM Kiva 26/06/2025 08:52 AM JST 4-TW T6.2 H36 W78 40A* 800V 0.5mm² - 6mm² 0.5mm² - 4mm²

Applications

  • Automation & Control Panels:

    Signal wiring for PLC I/O modules, sensor networks, and small actuators.

  • Machine Tool Distribution:

    Power feed to servomotors, spindle drives, and heating elements, benefiting from high vibration tolerance.

  • Building Management Systems:

    Secure termination of HVAC control circuits, lighting control wiring, and fire-alarm loops.

  • Transportation & Railway Equipment:

    Robust connections in rolling stock, ensuring electrical integrity through shocks and vibrations.

  • Industrial Power Distribution:

    Branching of 24 V, 48 V, or higher DC bus and AC control voltages in machinery and switchgear.

  • Renewable Energy Inverters:

    Termination of string inputs and auxiliary DC supplies in solar and wind inverters.

Basic knowledge

What Is a Spring Terminal Block?

A

spring terminal block

uses a spring steel or stainless-steel hairpin inside the terminal housing to clamp conductors when inserted. This design eliminates the need for manually tightening screws, providing tool-free conductor insertion and removal.

Advantages Over Screw Terminal Blocks

  • Faster Wiring:

    Instant wire insertion without screwdriver saves installation time.

  • Consistent Contact:

    Spring tension remains uniform over thermal cycles, reducing maintenance.

  • Reduced Risk of Over/Under Tightening:

    No torque-setting is needed, preventing conductor damage.

DIN Rail Mounting Standards

  • NS 35/7.5 vs. NS 35/15:

    JST blocks clip onto standard 35 mm rails—either the slimmer 7.5 mm-height version for compact layouts or the 15 mm rail for heavier assemblies.

Understanding Conductor Sizing

  • Always choose a JST model whose maximum wire size meets or exceeds the gauge needed. Undersized blocks can lead to poor contact or overheating; oversized blocks ensure safe, low-impedance connections.

Frequently asked questions

Q1: Can I insert stranded wires directly into JST blocks?


Yes. JST terminals securely hold both solid and stranded wires. For stranded wires, using ferrules can improve insertion consistency.

Q2: How do I release a wire from a JST spring terminal?


Use a flat-blade screwdriver or the integrated release button to depress the spring element, then pull the conductor out easily.

Q3: Are JST spring terminals suitable for high-vibration environments?


Absolutely. The spring mechanism consistently maintains clamping force even under continuous vibration, making them ideal for mobile machinery and rail applications.

Q4: What safety standards do JST blocks comply with?


JST Series uses UL94 V-0 flame-retardant PA66 housing and meets IEC/EN 60947-7-1 requirements for terminal blocks. They also conform to RoHS and REACH directives.

Q5: Can I stack or bridge multiple JST blocks?


Yes. JST blocks feature standardized lateral and vertical bridge slots, allowing quick installation of jumper bars or busbars for parallel or multi-pole circuit distribution.

Q6: What ambient temperatures are supported?


JST blocks operate safely from –20 °C to +70 °C. Ensure panels remain within this range and provide adequate ventilation for continuous loads.

Why use spring‑loaded terminal blocks in control wiring?

They ensure stable, vibration‑proof connections that maintain contact pressure without re‑tightening, ideal for long‑term panel reliability.

How do push‑in spring terminal blocks speed up installation?

Simply insert the conductor without tools; the spring mechanism locks it securely, reducing wiring time by up to 50%.

What’s the benefit of a DIN‑rail spring terminal block with a lever?

The lever allows easy conductor release without tools, making frequent wiring changes faster and safer.

When should I choose a 41A spring clamp terminal block?

For compact power distribution where high‑current capability and maintenance‑free performance are required.

Why choose a compact multi‑level spring terminal block?

It maximizes wiring density in control cabinets while maintaining clear circuit separation in a small footprint.

Product inquiry

Related products

Selection & support

Selecting LEIPOLE spring terminal blocks

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

Should I choose spring clamp or screw terminal blocks?

Spring terminals clamp the conductor as soon as it is pushed in, and stainless-steel springs keep the pressure constant under vibration and temperature changes, so there are no screws to retighten. Screw terminals suit installers who prefer tightening each conductor to a set torque.

Compare terminal block types

What wire sizes and voltage do JST spring terminal blocks take?

JST spring terminals take solid conductors from 0.14 mm² to 10 mm² (up to 6 mm² stranded) and are rated 17.5 to 52 A at up to 800 V, in flame-retardant PA66 (UL94 V-0). Each has a marking slot and bridge channels for linking circuits; ratings per model are in the table.

Check technical documents