The 1794-TBNF is a Flex I/O fused terminal base unit. This unit is a signal and power termination unit that is part of the Flex I/O distributed I/O platform of Allen-Bradley. This terminal base comes with Twenty (20) screw clamp terminals in Two (2) terminal strips wherein each terminal strip is comprised of Ten (10) connection points. Terminal strip 1 is designated for I/O wiring and COM connection. I/O terminals are assigned at terminals 0-14 (top) and terminals 1-15 (Bottom). COM terminals are located at terminals 16 and 33 (top) while + V terminals are designated at 34 and 51 (bottom) terminals. The 1794-TBNF is compatible for use with 1794-OA8 non-isolated eight (8) channel output module, 1794-OA8I isolated Eight (8) channel output module; 1794-OW8 Relay output module and 1794-OW8XT extended temperature relay output module. A single instance of 1794-TBNF is required per module. The 1794-TBNF has a maximum current rating of 10A and a working voltage rating of 24 VDC, 120 AC / DC, and 230 AC / DC. It has a backplane current draw of 640 mA @ 5VDC. The appropriate tightening Torque to be applied to each terminal is 1.4 Nm (12 lb-in.). The terminal base’ operating temperature is -20…55 °C (-4…131 °F) while the non-operating temperature is -40…85 °C with a relative humidity of 5-95 %, non-condensing. Primary parts of the 1794-TBNF include Female Flexbus connector, Terminal base unit, Male flexbus connector, Keyswitch, mounting holes, locking tab, module locking notch, cover plug, terminal strip cover, and Eight (8) 5 x 20 mm size internally installed fuse.

The 1794-TBNF Flex I/O Fused Terminal Base Unit by Allen-Bradley is a fused terminal base unit which provides 16 I/O connections and comes with 2 common terminals, 2 +V terminals, screw terminals, and a covering for I/O wiring. It has a voltage rating of 250V AC/DC with a maximum current rating of 10A and the base unit has a power rating of 650W. It provides 8 slow blow fuses with a 5 by 20mm fuse size and a fuse rating of 1.6A at 250V AC also provide I/O termination through spring clamp. The 1794-TBNF has a terminal screw torque of 1.4 Nm (12lb-in) and utilizes copper wire with 0.34 x 3.3 mm2 (22/12 AWG) copper wire rated at 75 deg. C (167 deg. F) wire size and with 1.2 mm (3/64 in) thick insulation. The 1794-TBNF provides a FLEXBUS rating of 640mA at 5V DC, with V/COM terminal voltage of 250V DC/AC at 50-60 Hz and a current of 10A. It is capable of 250V (continuous) maximum voltage isolation between field wiring terminals to FLEXBUS with basic insulation type but the actual isolation voltage depends solely on the installed module. The 1794-TBNF has an operational temperature range around -20-55 deg. C (-4-131 deg. F) and is stored at a -40-85 deg. C (-40-185 deg. F) temperature range. It has factory-designated T4A (NA) and IEC T4 temperature codes and comes in an open-style enclosure. The 1794-TBNF has a tested and rated operational shock withstand of 30G and can also maintain function at an operational vibration of 5G at 10-500 Hz vibrational frequency.