Why Choose the Lovato SRATH21 Two-Hand Control Safety Relay?
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.
Key Advantages
- Dedicated single-function safety relay for two-hand control devices.
- Supports safety systems up to Category 4, PLe according to ISO 13849-1.
- Suitable for Type IIIC two-hand control applications according to IEC/EN/BS 13851.
- Provides 2NO safety outputs using forcibly guided relay contacts.
- Includes 1 PNP system-status output for monitoring and signalling.
- External contactor feedback/EDM input supports downstream device monitoring.
- Compact 35 mm DIN rail mounting simplifies installation in control panels.
Key Features
- Lovato SRA series safety relay.
- Single-function two-hand control monitoring.
- 24 V DC nominal auxiliary supply.
- 2NO safety relay outputs.
- 1 PNP feedback/status output.
- Safety outputs use forcibly guided contacts.
- 2 safety inputs.
- Typical input current of 4.3 mA.
- External contactor feedback EDM capability.
- Safety performance up to Cat. 4 / PLe.
- 35 mm DIN rail mounting.
Reliable Two-Hand Safety Control for Machinery
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.
Typical Applications
- Two-hand operator control stations.
- Industrial presses and forming machinery.
- Cutting and processing machinery.
- Assembly and production equipment.
- Machines requiring two-hand initiation of hazardous movement.
- Industrial safety control panels.
- OEM machinery requiring Type IIIC two-hand control monitoring.
