The Allen-Bradley 1771-WB, also cataloged as the 1771-WB Wiring Arm, operates as a dedicated hardware component for field signal termination and swing-arm connection within Allen-Bradley 1771 I/O System chassis platforms.
The Allen-Bradley 1771-WB field wiring arm incorporates 12 gold-plated connection points engineered to minimize contact resistance and protect low-level signal paths against galvanic corrosion in harsh industrial atmospheres. Operating without active electronics, the passive termination block facilitates hot-swappable I/O module replacement without disconnecting field wiring, preserving circuit continuity across backplane bus slots. High-density screw clamps ensure stable physical retention for 14 AWG to 22 AWG solid or stranded wire conductors under continuous mechanical vibration.
Frequently Asked Questions
Q: Can the 1771-WB wiring arm be removed while the 1771 I/O rack is powered?
A: Yes. The wiring arm latches directly to the 1771 chassis frame. Unlatching and swinging the wiring arm away mechanically disconnects field wiring from the I/O module faceplate, allowing module removal while leaving power and field conductors intact.
Q: What wire gauge is supported by the 12 terminal connections on the 1771-WB?
A: The terminal screws accept wire sizes ranging from 14 AWG to 22 AWG solid or stranded copper wire. Torque terminal screws to 7-9 lb-in to ensure proper retention and minimal electrical contact resistance.
Q: Does the 1771-WB field wiring arm draw current from the 1771 backplane bus?
A: No. The 1771-WB is a non-powered mechanical connector interface with gold-plated contacts. It draws 0 mA from the backplane bus power supply.
Field Installation Guidelines
Ensure the 1771 chassis pivot pins are free of debris prior to mounting the wiring arm to the lower chassis rail.
Strip field conductor insulation back 0.375 inches (9.5 mm) without nicking or twisting individual copper strands.
Insert conductors fully into the designated 12 terminal locations and tighten retaining screws to specified torque limits.
Route field wiring bundles vertically down the wiring channel, keeping signal cables separated from AC power lines.
Pivot the wiring arm upward until the top retaining latch firmly engages with the installed 1771 I/O module faceplate.
