User guide

Chapter One
Overview
Introduction
Watlow’s Series 97 is a microprocessor-based controller with a single input, second auxiliary
input and four outputs. Input 1 is used to measure temperature from a thermocouple or
RTD sensor. Input 2 can be utilized as a remote reset switch or a hardware lockout switch.
With up to four outputs, the controller is versatile in handling applications that require a
high/low limit, alarms, retransmit and communications. The controller is so user friendly it
can be set up to display safety and limit messages created by the end user to meet the exact
application need.
The Series 97 limit controller is added to thermal applications to limit over-temperature
conditions. The Series 97 controller provides safety assurance against instances where a
high temperature runaway condition could occur from a shorted input sensor or an output
device that could fail in a closed position.
The Series 97 is recommended for any application where thermal runaway could result in
large product scrap costs, affect operator safety, cause damage to equipment, or create a fire
hazard.
The Series 97 is manufactured by ISO 9001-registered Watlow Winona and reliably backed
by a three-year warranty.
Figure 1.1 — Series 97 inputs and outputs.
Input 1
Process
Input 2
Remote Reset or
Hardware Lockout
Output 1
Limit Relay
Output 2
Alarm
Output 3
Alarm
Output 4
Alarm, Analog or
Communications
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LIMIT 97
1
RESET
Watlow Series 97 Overview ■ 1.1
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