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SMS20 – Safety module, 2NO out, man/auto/mon start
Carlo Gavazzi SMS20 is a 24 V AC/DC dual-channel safety relay module with two normally open safety outputs, automatic and manual reset functions, and Category 4 PL e capability for industrial machinery safety monitoring.
£128.64
Why Choose the Carlo Gavazzi SMS20 Safety Relay Module?
The SMS20 is a compact 24 V AC/DC safety relay module manufactured by Carlo Gavazzi, designed for monitoring emergency stop circuits, safety gates, interlocks, magnetic safety switches and safety limit switches. Although the supplied brand is listed as Unknown, SMS20 is an identifiable Carlo Gavazzi product reference.
Featuring two safety channels and two normally open (2NO) safety relay outputs, the SMS20 supports safety-related machine control applications requiring dependable monitoring and controlled output switching.
The module supports Category 4 and Performance Level e (PL e) safety architectures in accordance with EN ISO 13849-1, subject to the design and validation of the complete safety system. Its slim 17.5 mm DIN rail housing, detachable screw terminals and integrated LED diagnostics make it suitable for industrial control panels where space, serviceability and safety monitoring are important.
Key Advantages
- Dual-channel safety monitoring for compatible emergency stop and machine guarding circuits.
- Two normally open safety outputs for switching suitable safety-related control circuits.
- 24 V AC/DC power supply supports common industrial control voltages.
- Category 4, PL e capability in accordance with EN ISO 13849-1 when correctly integrated.
- Automatic, manual and monitored manual reset options provide installation flexibility.
- 17.5 mm slim housing saves space in electrical control panels.
- Detachable screw terminals simplify wiring and replacement.
- LED diagnostics indicate power, safety input and output status.
- 6 A maximum output current rating for suitable loads under specified conditions.
- Suitable for machinery safety and specified lift safety monitoring applications.
Key Features
- Carlo Gavazzi SMS Series safety monitoring module.
- Two-channel safety input monitoring.
- Two electromechanical normally open safety relay outputs.
- Forcibly guided safety relay technology.
- Emergency stop and guard monitoring functions.
- Compatible with suitable magnetic and electromechanical safety switches.
- Selectable automatic, manual or monitored manual start/reset.
- 24 V AC or DC operating supply.
- DIN rail mounting.
- Detachable, coded screw-terminal connections.
- LED indicators for supply, input channels and safety outputs.
- IP20 enclosure protection.
- Operating temperature range of −25 to +60 °C.
- Compact enclosure dimensions of 17.5 × 110.8 × 121.1 mm.
How the Carlo Gavazzi SMS20 Safety Module Works
The Carlo Gavazzi SMS20 monitors the state of connected safety input devices, such as emergency stop buttons, safety gate switches or compatible non-contact safety sensors.
When the safety inputs are in their permitted operating states and the configured start/reset conditions are satisfied, the module energises its two normally open safety relay outputs. These outputs can be used within a properly designed safety control circuit to enable external contactors or other suitable control devices.
If a monitored safety input opens, the SMS20 de-energises its safety outputs. The required restart sequence depends on whether automatic, manual or monitored manual reset has been configured.
Its dual-channel monitoring architecture supports fault detection and redundancy within appropriately designed safety circuits. However, the final safety category and performance level depend on the complete installation, including connected devices, wiring, diagnostic coverage and validation.
Typical Applications
- Emergency stop monitoring on industrial machinery.
- Machine guard and safety gate monitoring.
- Safety magnetic switch monitoring.
- Electromechanical safety limit switch circuits.
- Industrial automation safety control panels.
- Packaging and manufacturing machinery.
- Conveyor and material handling equipment.
- Machine access and interlocking systems.
- Lift car levelling and related safety monitoring applications.
- OEM machinery safety system integration.
Technical Specifications
| Manufacturer | Carlo Gavazzi |
|---|---|
| Part number | SMS20 |
| Product series | SMS Safety Modules |
| Product type | Safety relay / safety monitoring module |
| Nominal supply voltage | 24 V AC/DC |
| DC supply range | 21.6–26.4 V DC |
| Safety input channels | 2 |
| Safety outputs | 2 normally open relay contacts |
| Safety output terminals | 13–14 and 23–24 |
| Maximum output current | 6 A |
| Maximum quadratic current | 72 A² |
| Start/reset functions | Automatic, manual and monitored manual |
| Safety category capability | Category 4 |
| Performance level capability | PL e |
| Applicable machinery safety standard | EN ISO 13849-1 |
| Lift-related standards | EN 81-20 and EN 81-50 |
| Mounting | DIN rail |
| Electrical connections | Detachable screw terminals |
| Width | 17.5 mm |
| Height | 110.8 mm |
| Depth | 121.1 mm |
| Ingress protection | IP20 |
| Operating temperature | −25 to +60 °C |
| Status indication | LED indicators |
| EAN | 5709870397740 |
Frequently Asked Questions
Who manufactures the SMS20 safety relay?
The SMS20 is manufactured by Carlo Gavazzi and belongs to its industrial safety monitoring module range.
What is the Carlo Gavazzi SMS20 used for?
The SMS20 monitors safety circuits incorporating emergency stops, safety gates, magnetic safety switches, limit switches and interlocks in industrial machinery and specified lift applications.
What supply voltage does the SMS20 require?
The SMS20 operates from a nominal 24 V AC or 24 V DC power supply.
How many safety outputs does the SMS20 have?
The SMS20 provides two normally open safety relay outputs, identified by terminals 13–14 and 23–24.
Does the SMS20 support manual and automatic reset?
Yes. The SMS20 supports automatic, manual and monitored manual start/reset arrangements, allowing the restart function to be configured for the intended application.
What safety category does the SMS20 support?
The SMS20 is designed for use in systems achieving Category 4 and Performance Level e under EN ISO 13849-1, provided the complete safety-related control system is correctly designed and validated.
Is the SMS20 suitable for DIN rail installation?
Yes. The SMS20 is a DIN rail-mounted module with a 17.5 mm wide housing and detachable screw terminals.
What is the difference between the SMS20 and SMS31?
The SMS20 provides two normally open safety outputs, while the SMS31 provides three normally open safety outputs and one normally closed auxiliary contact.
Compact Safety Monitoring for Industrial Control Systems
The Carlo Gavazzi SMS20 combines dual-channel safety monitoring, two normally open safety relay outputs, 24 V AC/DC operation and flexible reset functions in a compact DIN rail-mounted module for industrial machinery safety applications.
