Phoenix 3214663 PTTBS 1,5/S-KNX Double-Level Terminal Block for KNX Bus Systems, Push-in Connection, Black/Red and White/Yellow

For KNX bus installations demanding compactness without sacrificing clarity, the Phoenix 3214663 PTTBS 1,5/S-KNX double-level terminal block packs four push-in connections into a footprint normally reserved for two. Its upper level carries the red/black KNX pair, while the lower level handles auxiliary white/yellow conductors — a color-coded layout that reduces wiring errors during commissioning and maintenance.

Highlights

• Two-level design with four push-in terminations: two per level, accepting solid or stranded conductors from 0.14 mm² to 1.5 mm² (AWG 26–16).
• KNX-specific color coding: upper level black/red, lower level white/yellow, matching standard KNX cable colors for instant identification.
• Rated for 500 V nominal voltage and 17.5 A nominal current (IEC), with 6 kV rated surge voltage — suitable for KNX bus and auxiliary circuits.
• Tool-free push-in connection: simply insert a stripped conductor (8–10 mm) for a secure, vibration-resistant termination.
• Mounts on standard DIN rail NS 35/7.5 or NS 35/15, enabling fast integration into distribution boards and control panels.
• Housing made of polyamide (PA) with UL 94 V0 flammability rating, ensuring fire safety in building installations.
• Wide operating temperature range from -60 °C to +105 °C, with pollution degree 3 and overvoltage category III for demanding environments.

In daily use

Installers benefit from the unmistakable color pairing: the upper level's black and red terminals mirror the KNX bus conductors, while the lower white and yellow terminals provide a dedicated point for auxiliary wiring such as additional power or signal lines. The push-in mechanism accepts both solid and stranded conductors without ferrules, speeding up panel assembly. The compact double-level footprint halves the rail space compared to two separate single-level blocks, leaving more room for other components. The PA housing withstands mechanical stress and maintains insulation integrity across the full temperature range, making it reliable in both heated and unheated locations.

Full specifications

• Connection method: Push-in
• Number of levels: 2
• Number of connections: 4 (2 per level)
• Nominal voltage (IEC): 500 V
• Nominal current (IEC): 17.5 A
• Rated surge voltage: 6 kV
• Conductor cross section solid: 0.14 mm² – 1.5 mm²
• Conductor cross section stranded: 0.14 mm² – 1.5 mm²
• AWG range: 26 – 16
• Stripping length: 8 – 10 mm
• Insulating material: Polyamide (PA)
• Connection point color coding: Upper level black/red, lower level white/yellow
• Mounting type: DIN rail NS 35/7.5 or NS 35/15
• Operating temperature: -60 °C to +105 °C
• Pollution degree: 3
• Overvoltage category: III
• Flammability rating (UL 94): V0
• Application: KNX bus systems

Final note

This terminal block is not a generic feed-through component — it is engineered specifically for KNX installations, with color-coded levels that align with standard bus wiring. Its push-in technology and dual-level density make it a practical choice for modern building automation projects.