Rockwell Automation 1771-PM , D17716.5.18 U MNL 1771-PM CLUTCH/BRAKE MOD - Manual (Page 72)

Field Wiring Arm Connections
Chapter 6
6Ć20
Install two separate cam limit switch assemblies each with three cams and
three cam limit switches. Connect cam limit switches exactly as shown in
Figure 6.9. This allows each voting processor to monitor its own limit
switches for:
top-stop-check (TCAM)
run-on (RCAM)
anti-repeat (ACAM)
Each cam limit switch assembly must be independently driven by the
press shaft through a separate coupling device. Couple each cam limit
switch assembly to the shaft through a separate direct coupling, a separate
gear assembly, or a separate chain assembly.
WARNING: To guard against injury to personnel and
damage to your press, install two separate cam limit switch
assemblies that are independently driven by the press shaft
through separate coupling devices.
Two separate cam limit switch assemblies allow your clutch/brake
controller to stop press motion in case there is a failure within either cam
limit switch assembly or a breakage in either coupling device.
Set each pair of cam limit switches to similar settings as shown in
Figure 5.1. If the settings are not similar, the voting processors can
disagree on their perceived shaft zones and cause nuisance shutdowns.
We recommend the Allen-Bradley Rotating Cam Limit Switch (cat. no.
803-P3). This rugged duty cam limit switch assembly is well suited for
press applications. For ordering information, see the Allen-Bradley
Industrial Control Catalog or contact your local Allen-Bradley sales
engineer or distributor.
Because the Cat. No. 803-P3 is an industrial grade heavy-duty limit
switch, we recommend that it switch a power circuit drawing at least 0.25
Amp. Install a 470 or 500 ohm 50-watt load resistor in parallel with the
AC input to generate this current.
You need to mount the resistors on the subpanel to keep dissipated heat
(from resistors) away from modules, and because the resistor’s axial leads
are not compatible with the wiring arm.
Cam Limit Switches