Push-In Terminal Blocks: Vibration-Resistant Connection for Industrial Controls

Push-in type terminal blocks use a stainless steel spring clamp to maintain constant contact pressure, delivering vibration-resistant, maintenance-free connections without re-torquing.

How Spring Clamp Resists Vibration

The spring clamp in a push in terminal block absorbs mechanical shock and thermal cycling—the two primary causes of screw connection loosening—by maintaining constant force without torque dependence.

• 🔹 Constant force application: Spring exerts steady pressure regardless of temperature fluctuations or vibration frequency. Spring cage terminal blocks maintain contact force of 8–12N across 500+ wire insertion cycles.

• 🔹 No re-torque required: Eliminates scheduled maintenance and torque errors common with screw terminals.

• 🔹 Gas-tight connection: Prevents oxidation and ensures stable signal transmission under continuous operation.

Test Standards & Performance

Push fit din rail terminals are tested per IEC 60068-2-6 (sinusoidal vibration) and IEC 60947-7-1 (short-circuit withstand). The spring mechanism dampens mechanical energy, preventing contact interruption exceeding one microsecond.

Test parameters under IEC 60068-2-6:

• Frequency range: 10 Hz to 150 Hz (sweep rate 1 octave/min)

• Acceleration: up to 5g (50 m/s²)

• Duration: 2 hours per axis (6 hours total on three axes)

• Requirement: zero signal interruption exceeding 1 microsecond

Additional testing per EN 61373 applies for railway and transportation applications.

Push-In vs. Screw Connection

In high-vibration environments such as conveyors, AGVs, and railway systems, spring-clamp technology maintains contact integrity without manual intervention.

Installation Steps

• Step 1: Strip the wire to the length specified (typically 8–10 mm).

• Step 2: For stranded wire, crimp a wire-end ferrule. Push fit terminal blocks require ferrules for stranded conductors—bare stranded wire is not accepted.

• Step 3: Insert the solid wire or ferrule straight into the terminal opening until resistance is felt.

• Step 4: Lightly pull the wire to confirm secure clamping—no tools required for solid wires.

Selection Criteria

Selecting the correct push in terminal block requires matching rated current, voltage, and wire gauge to the application. Housing material should meet UL94 V-0 flame resistance standards.

Mount on standard 35 mm DIN rails. Use end covers and partition plates for circuit isolation. Implement bridge systems for commoning connections across multiple terminals.

Common Challenge: Solid vs. Stranded Conductors

For stranded conductors without ferrules, the insertion force and pull-out retention differ significantly from solid wires. How does the spring clamp adapt to varying conductor stranding configurations without compromising vibration resistance?

Wiring Diagram
Thickness / Width / Height (mm)		5.2×48.8×35.3
Technical Parameters
Rated Data	Voltage (V)	800
	Current (A)	24
	Cross-section (mm²)	2.5
Crimping Range	Rigid Wire (mm²)	0.2-4
	Flexible Wire (mm²)	0.2-2.5
Insulating Material		PA
Flame retardant rating UL-94		V0
Stripping Length (mm)		10
Install the Guide Rails		TH35-7.5/TH35-15
		model
Partition plate		G
Plug-in Bridge	2P	FBS 2-5
	3P	FBS 3-5
	4P	FBS 4-5
	5P	FBS 5-5
	10P	FBS 10-5
Marker Strip	blank	ZB5
	Horizontal Printing	ZB5
	Vertical Printing	ZB5
Dimensions