Phoenix Contact ST 2,5-3L BU Multi-level Terminal Block

Technical Overview

3-level, 500V/20A spring-cage terminal block for 0.08-4mm² conductors. Operates -60°C to 110°C. Compact 5.2mm width.

Key Features

3-level design providing 6 connections for up to 3 potentials
Spring-cage connection method for reliable and vibration-resistant wiring
Supports rigid conductors from 0.08 mm² to 4 mm² (28-12 AWG)
Supports flexible conductors from 0.08 mm² to 2.5 mm² (28-14 AWG)
Nominal voltage of 500 V and nominal current of 20 A
Wide operating temperature range from -60 °C to 110 °C
DIN rail mountable on NS 35/7,5 and NS 35/15
Flammability rating according to UL 94: V0
Blue color (RAL 5015) for easy identification

Technical Specification Matrix

Parameter	Value
Nominal Voltage	500 V
Nominal Current	20 A
Rated Surge Voltage	6 kV
Number of Connections	6
Number of Rows	3
Potentials	3
Connection Method	Spring-cage connection
Rated Cross Section	2.5 mm²
Conductor Cross-Section Rigid (min-max)	0.08 mm² - 4 mm² (28-12 AWG)
Conductor Cross-Section Flexible (min-max)	0.08 mm² - 2.5 mm² (28-14 AWG)
Stripping Length	8 mm - 10 mm
Overvoltage Category	III
Degree of Pollution	3
Insulating Material	PA
Flammability Rating (UL 94)	V0
Operating Temperature Range	-60 °C ... 110 °C
Mounting Type	NS 35/7,5, NS 35/15 (DIN rail)
Color	Blue (RAL 5015)
Physical Weight (kg)	0.02
Dimensions L x W x H (cm)	9.95 x 0.52 x 5.8

Industrial Applications

1. High-Density Industrial Control Panel Wiring

This terminal block is ideal for high-density wiring in industrial control cabinets where panel space is severely limited. Its compact 5.2 mm width and 3-level design efficiently utilize vertical space, allowing for 6 connections across 3 distinct potentials.

Problem Solved

Solves the engineering challenge of accommodating numerous control and signal connections within constrained enclosure footprints while maintaining clear potential separation and reliable, vibration-resistant electrical integrity.

High-density wiringCompact control panelsSpace optimizationMulti-level connectionsDIN rail mountingIndustrial automation

2. Machine Control Systems in Dynamic Environments

Suitable for interconnecting components within machine control systems, particularly in environments subject to significant vibration, shock, or wide temperature fluctuations. The spring-cage connection ensures enduring contact integrity, and the -60°C to 110°C operating range guarantees stable performance.

Problem Solved

Addresses the critical need for secure and stable electrical terminations in industrial machinery, preventing intermittent faults and maintaining operational continuity despite mechanical stresses and extreme thermal conditions.

Vibration resistanceWide operating temperatureMachine controlSpring-cage technologyIndustrial machineryDynamic environments

3. Distributed Power and Signal Routing in Building Automation

Utilized in building automation sub-panels for organized distribution of 500V power or routing multiple control signals. Its 3-level structure enables segregated, compact wiring of various potentials, critical for complex building management systems.

Problem Solved

Provides a robust and space-efficient solution for managing diverse power and signal circuits within building automation infrastructure, ensuring electrical safety (500V, Overvoltage Cat III) and systematic wiring of different functional potentials.

Building automationPower distributionSignal routingMulti-potentialCompact designElectrical safetyDIN rail