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.