Rockwell Automation 1771-WHF, 1771-WHFB User Manual
Installation Instructions
To the Installer
Pre-installation Considerations
Fused Field Wiring Arm
Cat. No. 1771-WHF and -WHFB
This document describes:
• pre-installation considerations
• how to install the field wiring arm
• how to change a fuse on the field wiring arm
• product specifications
The fused field wiring arm provides individual output circuit protection.
It allows simple fuse replacement without removing the field wiring arm from
the I/O chassis.
Two versions are available, both of which are interchangeable with the
1771-WH field wiring arm:
• 1771-WHF - this wiring arm uses a 3 A fuse for each output. The
maximum continuous current should not exceed 2.0 A per fuse.
• 1771-WHFB - this wiring arm uses a 1.5 A fuse for each output. The
maximum continuous current should not exceed 1.1 A per fuse.
IMPORTANT
Fused field wiring arms require more clearance than
the 1771-WH field wiring arms. If you are installing
in a cabinet, make certain that your installation has
sufficient clearance for this wiring arm.
1 Publication 1771-IN072B-EN-P - December 2004
2 Fused Field Wiring Arm Cat. No. 1771-WHF and -WHFB
The following figure shows the minimum dimensions from the back of the
1771 I/O chassis to the front of the fused field wiring arm and to the front of
a typical wire bundle.
Back of Chassis
Top of Chassis
Fused wiring arm
Fuse holder
Installing the Fused Field Wiring Arm
195.6mm
To end of fuse holders
209.6mm
(8.25”)
(7.70”)
Maximum wire bundle
To install the fused field wiring arm:
IMPORTANT
If your application requires a single power source for
all circuits on the 16-point output module, install the
jumper supplied with the wiring arm to connect the
first 4 terminals (A, B, C and D) together. Refer to the
specific installation data for your output module for
wiring information.
1. Remove power from the wiring arm.
2. If replacing an existing wiring arm:
a. disconnect wiring from the terminals on the field wiring arm
b. release the tab securing the wiring arm to the module
c. swing the wiring arm downward and remove as shown in the
following figure
Wire bundle
Publication 1771-IN072B-EN-P - December 2004
3. Snap the 1771WHF or -WHFB wiring arm on the horizontal bar at the
bottom of the chassis as shown in the following figure.