ABB Pluto S46 V2 Programmable Safety Relay Model 2TLA020070R1800

The ABB Pluto S46 V2 (order code 2TLA020070R1800) is a programmable safety controller designed to replace multiple safety relays in machinery safety systems. It features 8 safety inputs and 2 safety outputs (redundant). The unit is configurable with intuitive software to implement emergency stop, light curtain, two-hand control, and guard door monitoring functions. Certified to PL e and SIL 3, the Pluto S46 V2 is suitable for high-risk machinery.

Input and Output Specifications

Safety inputs: 8 digital inputs, each can be configured as dual-channel (e.g., two emergency stop buttons) or single-channel with test pulses. Inputs accept 24V DC signals (safety-rated). Input current: 5mA at 24V. Response time configurable from 3ms to 500ms. Safety outputs: 2 redundant, forced-guided relay outputs (each output is a pair of normally open contacts). Contact rating: 6A at 250V AC, 6A at 30V DC (resistive). Outputs are suitable for driving contactors directly. Auxiliary (non-safe) output: 1 transistor output (24V DC, 100mA) for status indication to a PLC. The unit also includes a test pulse output for monitoring external wiring.

Programming and Configurability

Configuration is performed using ABB Pluto Manager software (free download). The software provides a library of pre-certified function blocks: emergency stop, light curtain (with or without blanking), safety mat, two-hand control, delay timer, and logic gates. No text programming is needed; the user drags and drops blocks and connects them. The program is transferred via a USB cable. Password protection prevents unauthorized changes. The unit can also be configured with the optional Pluto Display Panel for on-site diagnostics.

Logic and Diagnostics

The Pluto S46 V2 has internal memory for 20 function blocks and 40 logic steps. It performs self-diagnostics every millisecond, checking input circuitry, output contact welding, and cross-circuit faults. A built-in watchdog monitors the program execution time. Error codes are displayed on front LEDs (green/red pattern). The unit logs the last 10 faults with a timestamp. For remote diagnostics, the transistor output can be wired to a PLC input to signal a fault condition.

Power Supply

Power voltage: 24V DC (21.6-26.4V DC). Power consumption: 2W max plus output load current. The power supply is isolated from the I/O circuits. The unit has an internal fuse (non-replaceable) and reverse polarity protection. An external power supply must comply with safety extra low voltage (SELV/PELV) requirements. Inrush current: 20A for 1ms. The unit also filters short power interruptions (hold-up time >10ms).

Physical and Environmental

Dimensions: 110mm (H) x 45mm (W) x 110mm (D). Weight: 350g. Mounting: 35mm DIN rail. Protection rating: IP20 (housing) / IP40 (fitted onto rail with terminal covers). Operating temperature: -10°C to 55°C. Storage: -40°C to 85°C. Humidity: 10-95% non-condensing. Vibration: 1g at 10-55Hz. The unit is made of flame-retardant polycarbonate. All terminals are screw-clamp type for 0.2-2.5mm² wire.

Safety Certifications

The Pluto S46 V2 is certified by TÜV Rheinland according to: EN ISO 13849-1 (PL e, Category 4), IEC 62061 (SIL CL 3), EN 60947-5-1, and EN 61496-1. It also carries CE and UKCA marks. The unit is suitable for applications up to PLe / SIL3 without further redundancy. It meets the requirements for use in machines with safety integrity level 3 according to IEC 61508. The safety data: PFHd = 1.2E-8, MTTFd = 150 years.

Wiring and Installation

Connect the 24V DC supply to terminals A1 (+) and A2 (-). Emergency stop buttons connect to input 1 (S11 and S12) for dual-channel. Light curtains connect to inputs 1-2 for OSSD signals. Outputs (13-14, 23-24) are relay contacts. All safety inputs use the same 24V DC supply. The test pulse outputs (T1, T2) provide pulsed 24V to detect short circuits to 0V or +24V. Follow the wiring diagrams in the manual for Category 4 installations. Do not exceed 30mA on test outputs.

Applications

Typical applications include mechanical presses, injection molding machines, robotic cells, conveyor systems, packaging machinery, and woodworking equipment. The 8-input, 2-output configuration is ideal for small to medium safety systems where multiple safety functions must be integrated, such as emergency stop + guard door + light curtain on a single machine.

Replacement and Accessories

The Pluto S46 V2 replaces older Pluto models (S20, S30) and is backward compatible in programming via Software 3.0. Accessories: Pluto Keypad (for on-site display and reset), screw terminal cover (2TLA020057R0000), and label holder for I/O identification. The unit is also available in a version with spring-cage terminals (order code suffix). For larger I/O counts, consider Pluto B46 with 16 inputs.

Conclusion

The ABB Pluto S46 V2 programmable safety relay offers a flexible, certified solution for up to PL e safety functions. Its compact size and easy programming reduce panel space and installation time compared to hardwired safety relay banks.