Phoenix STU/STTCO/STS Series Terminal Blocks Selection Guide
Phoenix this batch of products covers 7 sub-series including STU (large-current multi-wire shunt terminals), STTCO-LG (grounding color-coded terminals), STS (multi-wire high-density terminals), ST-SI (auxiliary function terminals), and special terminals (STP/SSK/SRTK). The compatible wire cross-section ranges from 2.5mm² to 35mm², integrating multi-wire shunt, grounding protection, color coding, and signal indication functions. They are widely used in industrial power distribution cabinets, control systems, and high-density circuit wiring scenarios.
1. Core Model Classification & Product Descriptions
The series is categorized by structural and functional characteristics for quick matching of application needs, with key parameters including wire cross-section, connection type, and functional attributes:
1.1 STU Series Large-current Multi-wire Shunt Terminals
Designed for main circuit to branch circuit current distribution, realizing one large-spec main wire to multiple small-spec branch wires connection, suitable for power distribution system wiring.
| Product Code | Model | Key Features | Application Scenarios |
|---|---|---|---|
| 3033126 | STU 35/ 4X10 | 35mm² main wire, 4-way 10mm² branch wires | Heavy-power main circuit to 4-channel medium-power branch circuit shunt |
| 3033139 | STU 10/ 4X2,5 | 10mm² main wire, 4-way 2.5mm² branch wires | Medium-power main circuit to 4-channel low-power branch circuit shunt |
1.2 STTCO-LG Series Grounding Color-coded Terminals
Integrate grounding protection (PE) and color coding (GY=gray, BU=blue) functions, suitable for signal/power circuit identification and safety grounding in complex systems.
| Product Code | Model | Key Features | Application Scenarios |
|---|---|---|---|
| 3038370 | STTCO-LG 2,5/5 ZB-PE GY | 2.5mm², 5-pole, ZB structure, grounding, gray color | 2.5mm² gray signal circuit grounding protection |
| 2201573 | STTCO-LG 2,5/5 ZB-PE BU | 2.5mm², 5-pole, ZB structure, grounding, blue color | 2.5mm² blue signal circuit grounding protection |
| 3038888 | STTCO-LG 2,5/5 ZB GY | 2.5mm², 5-pole, ZB structure, gray color | 2.5mm² gray signal circuit general connection |
1.3 STS Series Multi-wire High-density Terminals
Featured with TWIN (dual-wire) and QUATTRO (quad-wire) connection structures, supporting single-wire, dual-wire, and quad-wire wiring; with grounding (PE) and color coding (BU/OG/RD) options, suitable for high-density circuit layout.
| Category | Product Code | Model | Key Features | Application Scenarios |
|---|---|---|---|---|
| 4mm² Spec | 3031665 | STS 4-TWIN | 4mm², dual-wire connection | 4mm² medium-power circuit high-density parallel wiring |
| 3031694 | STS 4-QUATTRO-PE | 4mm², quad-wire, grounding | 4mm² high-density circuit grounding protection | |
| 3036437 | STS 4 BU | 4mm², blue color-coded | 4mm² signal circuit identification and connection | |
| 2.5mm² Spec | 3031720 | STS 2,5-TWIN | 2.5mm², dual-wire connection | 2.5mm² low-power circuit high-density parallel wiring |
| 3031759 | STS 2,5-QUATTRO-PE | 2.5mm², quad-wire, grounding | 2.5mm² ultra-high-density circuit grounding protection | |
| 3037601 | STS 2,5 RD | 2.5mm², red color-coded | 2.5mm² power circuit identification and connection | |
| 3037009 | STS 2,5-TG | 2.5mm², test point function | 2.5mm² circuit on-site testing without disconnection | |
| 6mm² Spec | 3038121 | STS 6 | 6mm², single-wire connection | 6mm² medium-power circuit general connection |
| 3038147 | STS 6-PE | 6mm², grounding | 6mm² medium-power circuit grounding protection |
1.4 ST-SI Series Auxiliary Function Terminals
Include signal indication, surge protection, and auxiliary connection functions, matching UK series terminals for function expansion.
| Product Code | Model | Key Features | Application Scenarios |
|---|---|---|---|
| 0921037 | ST-SILED 24-UK 4 | 24V LED indication, matching UK 4 terminals | UK 4 terminal circuit power status monitoring |
| 0921053 | ST-SILA250-UK 4 | 250V surge protection, matching UK 4 terminals | UK 4 terminal circuit surge protection |
| 0920229 | ST-SI | Basic auxiliary terminal | Terminal block function expansion and signal branching |
1.5 Special Terminals (STP/STN/SSL/SSK/SRTK)
Cover small-spec connection, explosion-proof, and marking functions, suitable for special application scenarios.
| Product Code | Model | Key Features | Application Scenarios |
|---|---|---|---|
| 0800967 | STP 5-2 | 5mm², 2-pole terminal | 5mm² medium-power small-channel circuit connection |
| 0505055 | SSK 135 KER-EX | Explosion-proof terminal, KER-EX grade | Explosive environment circuit connection |
| 3029952 | SRTK 6 | 6mm² marking terminal | 6mm² circuit parameter labeling |
| 3043815 | SSL 2,5 | 2.5mm² special connection terminal | 2.5mm² precision signal circuit connection |
2. Quick Interpretation of Model Naming Rules
The naming logic of this batch of products follows Phoenix's standardized terminal specification, with each segment corresponding to clear product parameters:
| Naming Segment | Meaning | Explanation |
|---|---|---|
| STU/STTCO-LG/STS/ST-SI | Series Identifier | - STU: Large-current multi-wire shunt terminal- STTCO-LG: Grounding color-coded terminal- STS: Multi-wire high-density terminal- ST-SI: Auxiliary function terminal |
| X/X (35/4X10, 10/4X2,5) | STU Wire Spec | Front X = main wire cross-section; Rear X = branch wire spec & quantity |
| X (2.5/4/6/35) | Wire Cross-section | Compatible wire size (mm²), determines current-carrying capacity |
| /Y (5) | Pole Count | Number of connection channels |
| -TWIN/-QUATTRO | Connection Type | - TWIN: Dual-wire connection (1 terminal for 2 wires)- QUATTRO: Quad-wire connection (1 terminal for 4 wires) |
| -PE | Grounding Function | For circuit safety grounding protection |
| -BU/-OG/-RD/-GY | Color Coding | - BU = Blue, OG = Orange, RD = Red (signal/power circuit identification)- GY = Gray (general-purpose circuit) |
| -ZB | Structural Suffix | Phoenix proprietary ZB structure, enhancing connection stability |
| -TG | Test Point Function | Supports on-site circuit testing without disconnection |
| -EX | Explosion-proof Grade | For explosive environment application |
3. Core Advantages of This Batch of Products
- Multi-wire Shunt & High-density Wiring CapabilitySTU series realizes large-current main circuit to multi-branch shunt; STS series TWIN/QUATTRO structures save 50%–75% cabinet space, suitable for high-density control systems.
- Integrated Grounding & Identification FunctionsPE suffix models ensure circuit safety grounding; rich color coding realizes visual distinction between signal/power circuits, reducing maintenance errors in complex systems.
- Diversified Auxiliary Function ExpansionST-SI series provides LED indication and surge protection functions; special terminals like SSK meet explosion-proof requirements, with strong scenario adaptability.
- Wide Wire Spec CoverageCovers 2.5mm²–35mm² wire cross-sections, meeting the connection needs of low-power signal circuits, medium-power control circuits, and high-power main circuits.
4. Product Selection Suggestions
- Select by Current & Shunt Requirements
- For large-current main circuit shunt: Choose STU series models (e.g., STU 35/4X10 for heavy-power shunt, STU 10/4X2,5 for medium-power shunt).
- For 2.5–6mm² medium-low power circuits: Select STS series models (e.g., STS 2,5-TWIN for high-density wiring, STS 6-PE for grounding protection).
- Select by Wiring Density & Space Requirements
- For ultra-high-density wiring: Choose STS series QUATTRO quad-wire models (e.g., STS 4-QUATTRO-PE, STS 2,5-QUATTRO-PE).
- For standard parallel wiring: Select STS series TWIN dual-wire models (e.g., STS 4-TWIN, STS 2,5-TWIN).
- For single-wire general connection: Use STS series basic models (e.g., STS 4, STS 6).
- Select by Functional Requirements
- For circuit grounding protection: Prioritize PE suffix models (e.g., STS 4-QUATTRO-PE, STTCO-LG 2,5/5 ZB-PE GY).
- For signal/power circuit identification: Choose color-coded models (BU for signal, RD for power, e.g., STS 4 BU, STS 2,5 RD).
- For circuit status monitoring: Select ST-SILED 24-UK 4 indication terminals.
- For explosive environment application: Use SSK series explosion-proof terminals (e.g., SSK 135 KER-EX).
- For on-site circuit testing: Choose STS 2,5-TG models with test points.
Phoenix STU/STTCO/STS Series Terminal Blocks Selection Guide
