Lovato SRATH21 is a 24 V DC single-function safety relay for Type IIIC two-hand control devices with 2NO forcibly guided safety outputs, 1 PNP status output and safety performance up to Category 4, PLe.
£314.01
The Lovato SRATH21 is a single-function safety relay for two-hand control devices, designed to monitor safety-related machine-control circuits where simultaneous two-hand operation is required. Part of the Lovato SRA safety relay series, it provides two safety relay outputs plus a PNP status output in a compact DIN-rail-mounted module.
The SRATH21 provides 2NO safety outputs with forcibly guided contacts and 1 PNP system-status output. It also incorporates an external contactor feedback input (EDM), enabling the state of downstream contactors to be monitored as part of the safety control architecture.
Powered from 24 V DC, the SRATH21 supports two-hand control applications up to Category 4 and Performance Level e (PLe) according to ISO 13849-1. Lovato also specifies the module for Type IIIC two-hand control according to IEC/EN/BS 13851, making it suitable for safety-related machinery where operator hands must be kept away from hazardous movement during initiation.
Two-hand control systems are used where a hazardous machine movement should only be initiated while the operator is actively using both hands on the designated control devices. The Lovato SRATH21 monitors the two-hand commands and activates its two normally open safety outputs when the required input conditions are satisfied.
The module also provides an external contactor feedback input for monitoring downstream switching devices and a PNP system-status output for signalling. When correctly incorporated into a suitably designed safety system, the SRATH21 can support applications up to Category 4 / PLe.
| Manufacturer | Lovato Electric |
|---|---|
| Series | SRA |
| Model | SRATH21 |
| Product type | Single-function safety relay |
| Safety function | Two-hand control device monitoring |
| Two-hand control classification | Type IIIC according to IEC/EN/BS 13851 |
| Contact configuration | 2NO + 1PNP |
| Number of safety NO outputs | 2 |
| Feedback/status outputs | 1 PNP |
| Safety output type | Relays with forcibly guided contacts |
| Number of inputs | 2 |
| Input voltage | 0–30 V DC |
| Typical input current | 4.3 mA |
| Nominal auxiliary supply | 24 V DC |
| Overvoltage category | III |
| Insulation voltage | 4 kV |
| AC-1 output rating | 6 A at 250 V AC, 2000 VA |
| AC-15 output rating | 5 A at 230 V AC |
| DC-13 output rating | 2 A at 24 V DC |
| UL 508 rating | B300-Q300 pilot duty |
| ISO 13849-1 safety category | Category 4 |
| ISO 13849-1 performance level | PLe |
| Mechanical life | >107 cycles |
| Electrical life, AC-1 at 360 operations/h | 105 cycles |
| Mounting | 35 mm DIN rail |
| Front protection | IP40 |
| Terminal protection | IP20 |
| Pollution degree | 2 |
| Operating temperature | -25 to +55 °C |
| Storage temperature | -30 to +70 °C |
| Relative humidity | ≤95% |
| Weight | 150 g |
| Package dimensions | 127 × 113 × 36 mm |
| EAN | 8013975296141 |
| HS code | 85365080 |
| ETIM 8.0 | EC001449 – Device for monitoring of safety-related circuits |
The SRATH21 is a single-function safety relay for monitoring two-hand control devices, helping ensure that the required two-hand command conditions are met before its safety outputs are activated.
The SRATH21 provides 2NO safety relay outputs with forcibly guided contacts plus 1 PNP system-status output.
The SRATH21 is specified for safety-related applications up to Category 4 and Performance Level e (PLe) according to ISO 13849-1 when correctly incorporated into the overall safety system.
Yes. Lovato specifies the SRATH21 for monitoring Type IIIC two-hand control devices according to IEC/EN/BS 13851.
The SRATH21 has a nominal auxiliary supply of 24 V DC and is designed for mounting on a standard 35 mm DIN rail inside an appropriate control enclosure.
Lovato Electric SRA safety relays provide dedicated monitoring functions for safety-related industrial control systems, with the SRATH21 combining two-hand control monitoring, forcibly guided safety outputs and high safety performance for machinery applications.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...