Rockwell Automation 440C Guardmaster 440C-CR30 Configurable Safety Relay User Manual - Manual (Page 19)

Rockwell Automation Publication 440C-UM001C-EN-P - November 2014 19
Chapter
3
Power, Ground, and Wiring
Wiring Requirements and
Recommendation
• Allow for at least 50 mm (2 in.) between I/O wiring ducts or terminal
strips and the relay.
• Route incoming power to the relay by a path separate from the device
wiring. Where paths must cross, their intersection must be perpendicular.
• Do not run signal or communications wiring and power wiring in the same
conduit. Wires with different signal characteristics should be routed by
separate paths.
• Separate wiring by signal type. Bundle wiring with similar electrical
characteristics together.
• Separate input wiring from output wiring.
• Label wiring to all devices in the system. Use tape, shrink-tubing, or other
dependable means for labeling purposes. In addition to labeling, use
colored insulation to identify wiring based on signal characteristics. For
example, you can use blue for DC wiring and red for AC wiring.
• Disabling pulse testing on safety-related terminals, including dedicated
safety outputs and test-pulse source evaluating input signals, requires
protection (for example, cable conduit) and separated wiring of safety
signals to exclude potential cross loop faults.
WARNING: Before you install and wire any device, disconnect power to the
system.
WARNING: Calculate the maximum current in each power and common wire.
Observe all electrical codes dictating the maximum current allowable for each
wire size. Current above the maximum ratings can cause wiring to overheat,
which can cause damage.
IMPORTANT Fault exclusions for conductors and wiring must follow the requirements
according to EN ISO 13849-2 Table D.3 and D.4. A fault exclusion can reduce the
overall safety rating of the related safety function to a maximum of PL
d
per
EN ISO 13849-1