W A T L O W
is not a step-by-step, how-to manual. It is your
responsibility to be sure your wiring is
safe and meets the requirements of
applicable agency standards along
with national and local electrical
codes. If you’re unable to determine
which method of wiring will best suit
your needs, call your nearest Watlow
Sales Representative. Their
experience with all types of thermal
systems makes them an invaluable
source for advice. Sales offices are
listed on the back cover of this
catalog.System wiring is divided into two main areas—signal wiring and power
wiring. Signal wiring deals with input
signals (generated by the temperature
sensor) and output signals (generated
by the temperature controller). Power
wiring deals with supply power to the
temperature and power controllers
and the current that’s ultimately
delivered to the
heating element.Signal wiring is less straight forwardthan power wiring. Not only does it
have to conform to circuit designs, but must also be installed in such a way as to minimize the negative
effects of electrical noise present in any thermal system.This section will start with wiring
sensors to controllers and then wiring
power controllers to temperaturecontrollers. It also offers limit control
wiring examples which provide a
comprehensive system overview.
Plastics catalog - 7347 Reference Data
Wiring Practices
This section is devoted to thermalsystem wiring practices. In this
section are general guidelines for
successful integration of the different
thermal system components—
heaters, temperature
sensors,
temperature controllers and power
controllers. This section
Resources and Information Wiring Practices for a SuccessfulControl System
Reference Data Not long ago the majority of industrial
thermal systems were controlled by
electrical/mechanical devices that
were fairly immune to the negative
effects of electrical noise. The short-
est path for the wire was the best and
only path. Noise resistant wiringpractices just weren’t a concern. With the advent of today’s electronic
controllers, awareness of techniques
to minimize the disrupting effects ofelectrical “noise” is critical. 409
