Watlow Electric Micro-Based Autotuning Control SERIES 980/985 - Manual (Page 20)

Figure 22 -
DC Output (Open
Collector), output 2
Option "C" Wiring
Diagram.
Figure 23 -
6 Amp Mechanical
Relay,
Output 2, Option "D"
Wiring Diagram.
Output 2 Option “C", DC Output (Open Collector)
Model# 98_A- C 0-0000
__
9 - 8 Heat, Cool
+
or Alarm
Switched DC
Watlow’s solid state switch is a low current DC output (open collector) used to switch an
external power switching device such as a SSR or an electromechanical relay. The input
specifications of the power switching device must match those listed for the SS switch
output. The power switching device must provide isolation between the SS switch
output and load power since the SS switch output is a non-isolated output. Minimum
load resistance is 5 0 0 o h m s. Available current is 9mA minimum and 22mA maximum.
Output 2 Option “D”, 6 Amp Mechanical Relay
Model# 98_A- D 0 - 0000
- -
Mechanical
Relay
Mechanical Relay
The electromechanical relay is an electrical and mechanical device with moving parts.
When power is applied to the relay solenoid, contact closure is created through move-
ment of the “common” contact of the relay. Off state impedance is 20K ohms minimum.
20
WATLOW Series 980/985 User’s Manual InstaIl and Wire, Chapter 2