Phoenix Contact ST-REL4-HG220/21-21 Relay Connector with 220 V DC Coil
The Phoenix Contact ST-REL4-HG220/21-21 Relay Connector is a high-quality relay module built for precise control in industrial automation. It operates on 220 V DC and integrates a Hengstler miniature round relay that manages both small and large electrical loads with high reliability. Featuring two changeover contacts and gold-plated silver-tin oxide (AgSnO₂+Au) materials, it ensures stable signal transmission and long-term durability. The LED status indicator provides quick visual feedback, while its plug-in design simplifies installation in terminal block systems. Compact and transparent in construction, it is ideal for control cabinets where space efficiency and consistent performance are critical.
Engineered for high endurance and operational safety, the ST-REL4-HG220/21-21 offers dependable switching performance up to 6 A and withstands electrical stress with insulation levels of up to 2.5 kV AC. Its monostable, polarized coil drive ensures precise activation and prevents incorrect wiring. The built-in damping diode protects internal components from voltage spikes, extending service life. With a mechanical lifespan exceeding 10 million cycles, this relay connector supports long-term reliability in industrial control panels, machine tools, and process equipment. Designed for smooth integration, it combines durability, easy maintenance, and consistent switching accuracy—ideal for demanding automation environments.
Why ST-REL4-HG220/21-21?
Because it combines precision engineering and smart design in a compact form. The Phoenix Contact ST-REL4-HG220/21-21 delivers reliable switching for both low and high loads, integrates visual feedback through its LED indicator, and ensures secure, plug-in connectivity — making it a trusted choice for modern automation systems that demand speed, safety, and long service life.
What problem does it solve?
It eliminates the risk of unreliable control signals and premature relay wear in automation environments. By offering stable 220 V DC operation, protected coil circuits, and high-end contact materials, the ST-REL4-HG220/21-21 ensures smooth power switching, prevents downtime, and provides maintenance-free performance even in harsh industrial conditions.
Key Features & Specifications – Phoenix Contact ST-REL4-HG220/21-21: Article Number 2823434
| Feature | Details | Benefit |
|---|---|---|
| Product Type | Relay Connector Module | Combines relay and connector in one compact housing for efficient integration. |
| Nominal Input Voltage | 220 V DC | Perfect for DC-powered automation systems requiring high-voltage control. |
| Input Voltage Range | 198–242 V DC | Provides stable operation even with minor voltage fluctuations. |
| Contact Type | 2 Changeover Contacts (AgSnO₂ + Au) | Handles both small and large loads with reliable switching and low contact wear. |
| Continuous Current Rating | 6 A | Supports high current loads without overheating or performance drop. |
| Maximum Switching Voltage | 250 V AC/DC | Suitable for diverse industrial and control applications. |
| Operating Mode | Monostable, Polarized Coil | Ensures precise switching with polarity protection against wiring errors. |
| Protective Circuit | Damping Diode & Polarity Protection | Extends relay life and prevents damage from voltage spikes. |
| Response Time | 15 ms (typical) | Delivers fast switching suitable for real-time control applications. |
| Release Time | 25 ms (typical) | Ensures smooth reset operation between switching cycles. |
| Operating Voltage Display | Integrated LED | Provides quick visual feedback on relay status for easy maintenance. |
| Mechanical Lifespan | Approx. 10⁷ cycles | Long service life, reducing downtime and replacement frequency. |
| Mounting Type | Plug-in Mounting on Terminal Block | Simplifies installation and replacement in control panels. |
| Housing Material / Color | Transparent Housing | Allows visual inspection of internal components during operation. |
| Ambient Operating Temperature | -20°C to +60°C | Reliable performance across a wide range of industrial environments. |
| Dimensions (W x H x D) | 27 x 33 x 66.5 mm | Compact design ideal for space-limited automation cabinets. |
| Compatible Accessories | URELG 4-PMTK, UDK-RELG 4, URELG 4 Basic Terminal Blocks | Enables complete relay and terminal block system setup. |
| Standards & Approvals | DIN VDE 0110b, EAC Approved | Guarantees compliance with international safety and quality standards. |
Download ST-REL4-HG220/21-21 (2823434) Datasheet
Commercial Information – Phoenix Contact ST-REL4-HG220/21-21: Article Number 2823434
| Commercial Data | Details |
|---|---|
| GTIN (Global Trade Item Number) | 4017918077402 |
| Traffic Number / Customs Tariff Code | 85364900 |
| Weight per Piece (Excluding Packing) | 69.2 g |
| Weight per Piece (Including Packing) | 67.59 g |
| Country of Origin | Germany (DE) |
The Applications
1. PLC-Based Motor Control for Automated Packaging Systems
In automated packaging systems, PLCs often need to manage solenoids or compact DC motors that control sealing or feeding operations. The ST-REL4-HG220/21-21 enables safe signal isolation and stable load switching at 220 V DC, protecting both the controller and connected actuators. Its LED indicator offers quick visual confirmation of active states, reducing troubleshooting time. With high insulation and fast response, the relay ensures smooth, coordinated control within high-speed production lines while maintaining electrical integrity.
2. Safety Interlock in Chemical and Process Plants
In complex chemical or industrial processes, reliable safety interlocks are essential to prevent equipment malfunction or hazards. The ST-REL4-HG220/21-21 relay provides dependable switching with built-in polarity protection and damping diode circuits that safeguard against transient surges. Its transparent housing enables technicians to visually verify relay status during maintenance checks. With long service life and stable contact performance, it supports continuous operation in harsh, high-demand environments where downtime must be minimized.
3. Alarm and Signal Relay in Infrastructure Monitoring
For infrastructure systems like power distribution or water treatment, alarm circuits depend on accurate and fail-safe signal switching. The ST-REL4-HG220/21-21 allows control modules to activate alarms or emergency lighting through its dual changeover contacts, supporting redundant or multi-path designs. Its plug-in mounting simplifies on-site replacement, ensuring minimal service interruption. The module’s robust design withstands vibration and electrical noise, providing consistent operation for long-distance monitoring and alert systems.
4. Wind Turbine and Renewable Energy Control Systems
Within wind turbine nacelles or solar tracking systems, compact relay connectors must perform reliably under fluctuating conditions. The ST-REL4-HG220/21-21 offers high insulation strength and stable coil response at 220 V DC, ideal for controlling actuators, sensors, or brake systems. Its compact, DIN-rail compatible design saves space in tight control cabinets, while the damping diode suppresses voltage spikes caused by inductive loads. This enhances component longevity and ensures steady operation in renewable energy installations.
Related Products & Accessories – Phoenix Contact ST-REL4-HG220/21-21
| Category | Model | Part Number | Description | Benefits / Compatibility |
|---|---|---|---|---|
| Basic Terminal Block (Standard) | URELG 4-PMTK | 2820712 | 4-position basic terminal block with test pick-off on both sides and knife disconnection, suitable for NS 32 and NS 35/7.5 DIN rails. | Designed for ST-REL…, ST-OV…, and ST-OE… relay plugs; enables safe, testable relay mounting. |
| Basic Terminal Block (Double Connection) | UDK-RELG 4 | 2777056 | 4-position terminal block with double connection points of the same potential and integrated test pick-off. | Allows flexible wiring and simplified signal distribution for multiple relays in parallel. |
| Basic Terminal Block (Screw Type) | URELG 4 | 2820149 | Screw-connected terminal block with end cover, compatible with NS 32 and NS 35/7.5 DIN rails. | Provides firm, vibration-resistant wire termination and reliable long-term electrical contact. |
| Mounting Rail Option | NS 35/7.5 DIN Rail | — | Standard DIN mounting rail for relay and terminal block installation. | Ensures secure, standard-compliant installation in control panels and cabinets. |
| Replacement Relay Module | Hengstler Miniature Round Relay (AgSnO₂+Au) | — | High-quality gold-plated contact relay insert, replaceable within the ST-REL4 housing. | Extends service life and maintains consistent switching performance under high load cycles. |
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