User`s guide

Chapter 2: Installation Series D8 User’s Guide
20 Watlow Anafaze Doc. 0600-3120-2000
System Wiring
Successful installation and operation of the control system can
depend on placement of the components and on selection of
the proper cables, sensors and peripheral components.
Routing and shielding of sensor wires and proper grounding
of components can insure a robust control system. This sec-
tion includes wiring recommendations, instructions for proper
grounding and noise suppression, and considerations for
avoiding ground loops.
WARNING! To reduce the risk of electrical shock, fire,
and equipment damage, follow all local and
national electrical codes. Correct wire sizes,
fuses and thermal breakers are essential for
safe operation of this equipment.
CAUTION! Do not wire bundles of low-voltage signal
and control circuits next to bundles of high-
voltage ac wiring. High voltage may be induc-
tively coupled onto the low-voltage circuits,
which may damage the controller or induce
noise and cause poor control.
Physically separate high-voltage circuits
from low-voltage circuits and from D8 hard-
ware. If possible, install high-voltage ac pow-
er circuits in a separate panel.
Wiring Recommendations
Follow these guidelines for selecting wires and cables:
• Use stranded wire. (Solid wire can be used for fixed ser-
vice; it makes intermittent connections when you move it
for maintenance.)
• Use 20 AWG (0.5 mm
2
) thermocouple extension wire.
Larger or smaller sizes may be difficult to install, may
break easily or may cause intermittent connections.
• Use shielded wire. The electrical shield protects the sig-
nals and the D8 from electrical noise. Connect one end of
the input and output wiring shield to earth ground.
• Use copper wire for all connections other than thermo-
couple sensor inputs.