Watlow CLS200 - Manual (Page 37)

CLS200 Series User’s Guide Chapter 2: Installation
Doc.# 0600-3050-2000 Watlow Anafaze 21
System Wiring
Successful installation and operation of the control system
can depend on placement of the components and on selec-
tion of the proper cables, sensors, and peripheral compo-
nents.
Routing and shielding of sensor wires and proper ground-
ing of components can insure a robust control system. This
section includes wiring recommendations, instructions for
proper grounding and noise suppression, and consider-
ations 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 CLS200
hardware. If possible, install high-voltage ac
power 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
service; 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
signals and the CLS200 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.