Watlow 8LS Controller - Manual (Page 11)

Overview
8LS User’s Guide 3
Safety
Watlow Anafaze has made efforts to ensure the reliability and safety of
the 8LS

controller and to recommend safe usage practices in systems
applications. Please note that, in any application, failures can occur.
These failures may result in full control outputs or other outputs which
may cause damage to or unsafe conditions in the equipment or process
connected to the 8LS controller.
Good engineering practices, electrical codes, and insurance regulations
require that you use independent external safety devices to prevent
potentially dangerous or unsafe conditions. Assume that the Watlow
Anafaze 8LS controller can fail with outputs full on, outputs full off, or
that other unexpected conditions can occur.
Install high or low temperature protection in systems where an
overtemperature or undertemperature fault condition could present a fire
hazard or other hazard. Failure to install temperature control protection
where a potential hazard exists could result in damage to equipment and
property, and injury to personnel.
The 8LS includes a reset circuit that sets the control outputs off or to the
data stored in memory if the microprocessor resets
— normally the result
of a power failure and power return. If a memory-based restart will be
unsafe for your process, program the 8LS controller to restart with
outputs off. For additional safety, program the computer or other host
device to automatically reload the desired operating constants or process
values on return of operating power. However, these safety features do
not eliminate the need for external, independent safety devices in
potentially dangerous or unsafe conditions.
Watlow Anafaze also offers ANASOFT ® , an optional software
program for IBM-AT ® or IBM-PC ® compatible computers. In the
event of a reset, ANASOFT will reload the 8LS controller with the
current values in computer memory. The user must ensure that this reset
will be safe for the process. Again, use of ANASOFT does not eliminate
the need for appropriate external, independent, safety devices.
Contact Watlow Anafaze immediately if you have any questions about
system safety or system operation.