Phoenix ST-REL Series: Industrial Relay Modules - Selection Guide
Product Overview
The Phoenix ST-REL Series comprises high-reliability industrial relay modules designed for switching and control applications in automation systems. Covering 2-channel (ST-REL2), 3-channel (ST-REL3), 4-channel (ST-REL4), and 7-channel (ST-REL7) configurations, these modules support control voltages from 24V DC/AC to 230V AC/DC, with contact configurations including dual changeover (21-21), single changeover (21), and single normally open (1) variants. Featuring robust construction, 35mm DIN rail mounting, and compliance with global industrial standards, they’re ideal for controlling actuators, valves, motors, and other industrial loads in manufacturing, process automation, and control cabinet applications where reliability and switching performance are critical.
Model Quick Reference Table
1. ST-REL7 Series (7-Channel Relay Modules)
| Model No. |
Product Name |
Control Voltage |
Contact Configuration |
Key Features |
Application Scenarios |
| 2892520 |
ST-REL7-KG 24/21-21 |
24V DC/AC |
7-channel, dual changeover (21-21) |
KG variant, high reliability |
24V DC/AC multi-channel dual-load control |
| 2827197 |
ST-REL7-HW230/4X21 |
230V AC |
4-channel, single changeover (21) |
HW variant, AC control |
230V AC 4-channel load switching (e.g., pumps, fans) |
| 2892465 |
ST-REL7-HG220/4X21 |
220V DC |
4-channel, single changeover (21) |
HG variant, DC control |
220V DC 4-channel industrial load control |
| 2899303 |
ST-REL7-HG110/4X21 |
110V DC |
4-channel, single changeover (21) |
HG variant, medium voltage |
110V DC 4-channel control circuits |
| 2892740 |
ST-REL7-HG 48/4X21 |
48V DC |
4-channel, single changeover (21) |
HG variant, low voltage |
48V DC 4-channel sensor/actuator control |
| 2827139 |
ST-REL7-HG 24/4X21 |
24V DC/AC |
4-channel, single changeover (21) |
HG variant, universal voltage |
24V DC/AC 4-channel general automation control |
2. ST-REL4 Series (4-Channel Relay Modules)
| Model No. |
Product Name |
Control Voltage |
Contact Configuration |
Key Features |
Application Scenarios |
| 2826431 |
ST-REL4-KG230/21-21/AU |
230V AC |
4-channel, dual changeover (21-21) |
KG variant, AU suffix |
230V AC 4-channel dual-load switching (safety circuits) |
| 2822419 |
ST-REL4-KG230/21-21 |
230V AC |
4-channel, dual changeover (21-21) |
KG variant, standard design |
230V AC 4-channel dual-load control |
| 2826198 |
ST-REL4-KG230/1-1/AU |
230V AC |
4-channel, single normally open (1) |
KG variant, AU suffix |
230V AC 4-channel single-load switching |
| 2823337 |
ST-REL4-KG120/21-21 |
120V AC |
4-channel, dual changeover (21-21) |
KG variant, medium voltage |
120V AC 4-channel dual-load control |
| 2829551 |
ST-REL4-KG 24/21-21/AU |
24V DC/AC |
4-channel, dual changeover (21-21) |
KG variant, AU suffix |
24V DC/AC 4-channel dual-load switching (automation) |
| 2823308 |
ST-REL4-KG 24/21-21 |
24V DC/AC |
4-channel, dual changeover (21-21) |
KG variant, standard design |
24V DC/AC 4-channel general control |
| 2852353 |
ST-REL4-KG 24/1-1 |
24V DC/AC |
4-channel, single normally open (1) |
KG variant, compact |
24V DC/AC 4-channel low-power load control |
| 2823434 |
ST-REL4-HG220/21-21 |
220V DC |
4-channel, dual changeover (21-21) |
HG variant, DC control |
220V DC 4-channel dual-load switching |
| 2823405 |
ST-REL4-HG 24/21-21 |
24V DC/AC |
4-channel, dual changeover (21-21) |
HG variant, universal voltage |
24V DC/AC 4-channel reliable load control |
3. ST-REL3 Series (3-Channel Relay Modules)
| Model No. |
Product Name |
Control Voltage |
Contact Configuration |
Key Features |
Application Scenarios |
| 2824255 |
ST-REL3-SG-B 24/21/P |
24V DC/AC |
3-channel, single changeover (21) |
SG-B variant, P suffix |
24V DC/AC 3-channel specialized load control |
| 2832027 |
ST-REL3-KG230/21/SO46 |
230V AC |
3-channel, single changeover (21) |
KG variant, SO46 interface |
230V AC 3-channel load control with SO46 compatibility |
| 2822406 |
ST-REL3-KG230/21 |
230V AC |
3-channel, single changeover (21) |
KG variant, standard design |
230V AC 3-channel general industrial control |
| 2821164 |
ST-REL3-KG120/21 |
120V AC |
3-channel, single changeover (21) |
KG variant, medium voltage |
120V AC 3-channel load switching |
| 2826091 |
ST-REL3-KG 24/21/SO46 |
24V DC/AC |
3-channel, single changeover (21) |
KG variant, SO46 interface |
24V DC/AC 3-channel control with SO46 integration |
| 2824190 |
ST-REL3-KG 24/21 AU |
24V DC/AC |
3-channel, single changeover (21) |
KG variant, AU suffix |
24V DC/AC 3-channel enhanced reliability control |
| 2861014 |
ST-REL3-KG 24/21 |
24V DC/AC |
3-channel, single changeover (21) |
KG variant, standard design |
24V DC/AC 3-channel automation control |
| 2821083 |
ST-REL3-HW230/21 |
230V AC |
3-channel, single changeover (21) |
HW variant, AC control |
230V AC 3-channel heavy-load switching |
4. ST-REL2 Series (2-Channel Relay Modules)
| Model No. |
Product Name |
Control Voltage |
Contact Configuration |
Key Features |
Application Scenarios |
| 2826486 |
ST-REL2-KG230AC/1AU |
230V AC |
2-channel, single normally open (1) |
KG variant, AU suffix |
230V AC 2-channel enhanced reliability switching |
| 2826525 |
ST-REL2-KG230AC/1 |
230V AC |
2-channel, single normally open (1) |
KG variant, standard design |
230V AC 2-channel general load control |
| 2826512 |
ST-REL2-KG220DC/1 |
220V DC |
2-channel, single normally open (1) |
KG variant, DC control |
220V DC 2-channel industrial load switching |
| 2823670 |
ST-REL2-KG 24/2 |
24V DC/AC |
2-channel, dual normally open (2) |
KG variant, high current |
24V DC/AC 2-channel high-power load control |
| 2823722 |
ST-REL2-KG 24/1AU |
24V DC/AC |
2-channel, single normally open (1) |
KG variant, AU suffix |
24V DC/AC 2-channel enhanced reliability control |
| 2823625 |
ST-REL2-KG 24/1 |
24V DC/AC |
2-channel, single normally open (1) |
KG variant, standard design |
24V DC/AC 2-channel compact control circuits |
Core Technical Specifications (Universal)
| Parameter |
Value |
Notes |
| Control Voltage Range |
24V DC/AC, 48V DC, 110V DC, 120V AC, 220V DC, 230V AC |
Model-dependent universal/DC/AC options |
| Contact Rating |
10A @ 250V AC, 5A @ 24V DC |
Handles standard industrial loads |
| Contact Configuration |
21 (single changeover), 21-21 (dual changeover), 1 (single NO), 2 (dual NO) |
Model-dependent switching options |
| Operating Temperature |
-25℃~70℃ |
Adapts to harsh industrial environments |
| Mounting Type |
35mm DIN rail (NS 35/7.5) |
Compact design for space-saving cabinet layout |
| Protection Class |
IP20 (cabinet mounting) |
Dust-proof for industrial control cabinets |
| Insulation Voltage |
4kV (coil-contact) |
Anti-interference, protects control systems |
| Certifications |
CE, UL, CSA, IEC 61810 |
Global industrial compliance |
| Power Consumption |
≤3W per channel |
Low heat generation for dense mounting |
| Mechanical Life |
≥10 million operations |
High reliability for long-term use |
Application Scenarios & Recommended Models
1. Multi-Channel Dual-Load Control (24V DC/AC)
- Requirement: 4-channel dual changeover control for 24V DC/AC automation systems
- Recommended Model: 2823308 (ST-REL4-KG 24/21-21)
- Key Reason: 4-channel dual changeover (21-21) configuration; KG variant reliability for general automation
2. High-Voltage Heavy-Load Switching (230V AC)
- Requirement: 3-channel 230V AC heavy-load control (e.g., industrial fans/pumps)
- Recommended Model: 2821083 (ST-REL3-HW230/21)
- Key Reason: HW variant optimized for AC heavy loads; single changeover (21) for versatile switching
3. Compact 2-Channel Control (24V DC/AC)
- Requirement: 2-channel single-load control for space-constrained cabinets
- Recommended Model: 2823625 (ST-REL2-KG 24/1)
- Key Reason: Compact 2-channel design; standard single NO contact for simple load switching
4. Safety-Critical Dual-Load Switching (230V AC)
- Requirement: 4-channel enhanced reliability dual-load control for safety circuits
- Recommended Model: 2826431 (ST-REL4-KG230/21-21/AU)
- Key Reason: AU suffix for enhanced reliability; dual changeover (21-21) for fail-safe applications
5. Medium-Voltage Control (110V DC/120V AC)
- Requirement: 4-channel 120V AC dual-load control or 7-channel 110V DC load switching
- Recommended Models: 2823337 (120V AC), 2899303 (110V DC)
- Key Reason: Voltage-matched variants; multiple channels for medium-scale control systems
Core Advantages
- Multi-Channel Flexibility: 2~7 channel configurations cover small-to-large scale load control needs
- Wide Voltage Compatibility: 24V~230V AC/DC control voltages fit global industrial standards
- Diverse Contact Options: Single/dual changeover (21/21-21) and normally open (1/2) contacts for versatile switching
- Industrial-Grade Reliability: -25℃~70℃ operating temperature, 4kV insulation, and ≥10 million mechanical operations
- Enhanced Variants: AU suffix for improved reliability; SO46 interface for system compatibility
- Easy Installation: 35mm DIN rail mounting and standardized wiring for quick deployment
- Global Compliance: CE/UL/CSA certifications enable international industrial applications
Installation & Usage Notes
- Voltage Matching: Ensure control voltage aligns with module rating (AC/DC-specific models must match power type)
- Contact Configuration: Select 21 (changeover) for dual-load switching, 1/2 (NO) for single-load control
- Current Limitation: Do not exceed 10A/250V AC or 5A/24V DC contact rating; use contactors for higher loads
- Mounting Spacing: Reserve ≥5mm between modules for heat dissipation, especially for 7-channel variants
- Wiring Specifications: Use 0.5~2.5mm² conductors; tighten terminals to 0.5~0.8Nm for secure connections
- Safety Wiring: For safety circuits, use AU-suffixed models and separate control/power wiring by ≥10mm
- Maintenance Checks: Regularly inspect module status indicators (if equipped) and terminal tightness; replace modules with worn contacts
