Why Choose the ABB Sentry SSR42 24VDC 2TLA010053R0400 Safety Relay?
The ABB Sentry SSR42 24VDC 2TLA010053R0400 is a compact machine safety relay with immediate and delayed safety outputs, designed for monitoring safety-related circuits in industrial machinery and automation systems. Part of ABB's Sentry SSR family, the SSR42 can monitor safety devices with contacts using one or two equivalent channels, as well as compatible safety devices equipped with OSSD outputs.
Operating from a 24 V DC supply, the SSR42 provides 2 NO immediate failsafe relay outputs plus 2 delayed NO failsafe relay outputs. The two delayed contacts incorporate a fixed 1.5 s OFF-delay, allowing selected machine functions to remain active for a controlled period after a safety demand while the two immediate outputs respond without the intentional delay.
The SSR42 supports manual or automatic reset, selectable by a switch on the front of the relay, and is suitable for monitoring emergency stops, safety gate switches and compatible OSSD devices such as light curtains. The 2TLA010053R0400 version uses screw-compression connection blocks and a slim 22.5 mm wide DIN rail housing. ABB specifies Sentry safety relays for applications up to PL e / SIL 3 when correctly configured, integrated and validated.
Key Advantages
- Combines immediate and delayed safety outputs in one compact relay.
- 2 NO immediate + 2 NO delayed failsafe relay outputs.
- Fixed 1.5 s OFF-delay on the two delayed outputs.
- 24 V DC supply for standard industrial machine-safety systems.
- Supports safety devices with one or two equivalent contact channels.
- Compatible with appropriate safety devices using OSSD outputs.
- Suitable for emergency-stop and safety gate monitoring.
- Manual or automatic reset selectable from the relay front.
- Supports safety applications up to PL e / SIL 3 when correctly integrated.
- Compact 22.5 mm wide DIN rail design conserves control-panel space.
Key Features
- ABB Sentry SSR42 safety relay.
- Manufacturer part number 2TLA010053R0400.
- 24 V DC rated control supply.
- 2 NO immediate failsafe relay outputs.
- 2 NO delayed failsafe relay outputs.
- 1.5 s fixed OFF-delay on the delayed outputs.
- Single-channel contact safety-device monitoring.
- Dual equivalent-channel contact safety-device monitoring.
- Compatible OSSD safety-device monitoring.
- Emergency-stop monitoring.
- Safety gate-switch monitoring.
- Manual / automatic reset selection.
- Front-mounted reset-selection switch.
- Rated operational current of 3 A for applicable AC-15 and DC-13 utilisation categories.
- Screw-compression connection blocks.
- IP20 degree of protection.
- DIN rail mounting to IEC 60715.
The ABB Sentry SSR42 combines two immediate and two delayed failsafe contacts within a single compact safety relay. When the monitored safety circuit changes to an unsafe state, the two immediate normally open outputs can respond directly while the remaining two normally open outputs are held for the fixed 1.5 s OFF-delay before opening. This arrangement can support controlled stopping sequences where one part of the machinery must remain enabled briefly while another safety function is removed immediately.
Input monitoring supports contact-based safety devices using either one channel or two equivalent channels, together with compatible OSSD-output safety devices. Manual or automatic reset can be selected using the front-mounted switch, allowing the relay's restart behaviour to be matched to the requirements of the machinery safety function. The combination of contact monitoring, OSSD compatibility and delayed outputs makes the SSR42 particularly useful where controlled machine run-down is required.
Typical Applications
- Emergency-stop safety circuits.
- Safety gate and guard-switch monitoring.
- Light curtain and compatible OSSD safety-device monitoring.
- Machinery requiring immediate and delayed safety outputs.
- Controlled machine stopping and run-down sequences.
- Motor, drive and contactor shutdown sequencing.
- Industrial automation and assembly lines.
- Production and packaging machinery.
- Food and beverage processing equipment.
- Pharmaceutical manufacturing machinery.
- Conveyor and material-handling systems.
- Industrial control panels requiring a fixed 1.5 s safety OFF-delay.
