ABB 3BSC690075R1 TU890 MTU 8 Ch 50V

ABB 3BSC690075R1 TU890: Compact MTU for S800 I/O Intrinsic Safety Applications

The ABB 3BSC690075R1 belongs to the TU890 series of compact Module Termination Units. This MTU serves as a passive connection point between field wiring, power supplies, and S800 I/O modules. Additionally, it contains a part of the ModuleBus for seamless communication. The TU890 distributes the ModuleBus to the I/O module and forwards it to the next MTU in line. Furthermore, it generates the correct address by shifting outgoing position signals to the next unit. You will find gray terminals for field signals and process voltage connections on this device.

Technical Specifications of the 3BSC690075R1 TU890

The 3BSC690075R1 supports up to 8 I/O channels. Its maximum rated voltage is 50 V, while the maximum rated current reaches 2 A per channel. However, the connected I/O module design primarily constrains these values for certified applications. For instance, the TU890 works specifically with AI890, AI893, AI895, AO890, AO895, DI890, and DO890 modules. The dielectric test voltage is rated at 500 V a.c. This makes the MTU suitable for demanding environments, including intrinsic safety zones.

Process connections use 27 blue terminals on the ABB TU890. Acceptable wire sizes for the process connector include solid 0.2–4 mm² or stranded 0.2–2.5 mm² (24–12 AWG). For the power supply connector, use 0.25–2.5 mm² (24–14 AWG). Recommended torque across all terminals is 0.5–0.6 Nm. The 3BSC690075R1 operates with a single I/O configuration, not redundant setups.

Mechanical Dimensions and Mounting

The ABB 3BSC690075R1 measures 64 mm in width including the connector, or 58.5 mm edge to edge when installed. Depth is 58 mm, or 106 mm including terminals. Height reaches 194 mm including the latch. Weighing only 0.17 kg, this MTU remains extremely lightweight. Mounting is horizontal only, with a detailed ambient temperature limit of 55 °C (131 °F). For vertical mounting, the maximum drops to 40 °C (104 °F). Thus, proper orientation ensures reliable long-term operation.

Environmental Certifications and Safety

The TU890 carries a CE mark and meets EN 61010-1 and EN 61010-2-201 for electrical safety. For hazardous locations, it holds ATEX/IECEx Zone 2 certification with an interface to Zone 0. Additionally, it features cFMus Class I, Division 2/Zone 2 with interface to Class I, II, III Division 1/Zone 0. Marine certifications include ABS, BV, DNV-GL, and LR. Operating temperature ranges from 0 to +55 °C (+32 to +131 °F), while storage spans -40 to +70 °C (-40 to +158 °F). Relative humidity sits at 5 to 95% non-condensing.

Pollution degree is 2 per IEC 60664-1, and corrosion protection meets ISA-S71.04: G3. Protection class is IP20 according to IEC 60529. Mechanical operating conditions follow IEC/EN 61131-2. EMC compliance includes EN 61000-6-4 and EN 61000-6-2. Overvoltage categories align with IEC/EN 60664-1 and EN 50178. Equipment class is Class I (earth protected) per IEC 61140. Finally, RoHS compliance follows EN 50581:2012, and WEEE compliance adheres to DIRECTIVE/2012/19/EU.

Frequently Asked Questions (FAQ)

1. Can the ABB 3BSC690075R1 be used with redundant I/O configurations?
No, the TU890 is designed exclusively for single I/O configurations. For redundant applications, please consult the ABB S800 I/O product selector.

2. What is the difference between the TU890 and the TU836V1?
The 3BSC690075R1 TU890 is a compact MTU for 50V intrinsic safety applications, while the TU836V1 handles 250V and 3A per channel. Furthermore, the TU890 uses blue terminals and supports hazardous location certifications.

3. How does the TU890 generate addresses for multiple MTUs on the same ModuleBus?
The ABB TU890 shifts outgoing position signals to the next MTU. This daisy-chain method ensures each connected I/O module receives a unique hardware address without any software configuration.

4. Is the 3BSC690075R1 suitable for vertical mounting?
Yes, but with a reduced maximum ambient temperature of 40 °C (104 °F). For horizontal mounting, the TU890 operates reliably up to 55 °C (131 °F) as per its specifications.

5. What wire sizes are acceptable for the power supply connector on the TU890?
The power supply connector on the ABB 3BSC690075R1 accepts 0.25–2.5 mm² stranded wire or 24–14 AWG. Always use the recommended torque of 0.5–0.6 Nm to ensure proper connections.