User Guide

599 Series Zone Valve 2-way, 3-way Thermic Actuators Technical Instructions
Document Number 155-780
March 15, 2013
Siemens Industry, Inc. Page 3
Mechanical Design,
Continued
Two-position Control
The actuator can be installed in any 24 Vac/Vdc control loop for two-position control or
pulse width modulation (PWM) control).
Position and Movement
Indication
STA73U
Figure 1. STA73U
Position and Movement Indication.
In this position the STA73U actuator is de-
energized. The actuator shaft is extended
and the valve is closed.
In this position the STA73U actuator is
connected to the power supply for at least
4-1/2 minutes. The actuator shaft is
retracted and the valve is open.
STP73U
Figure 2. STP73U
Position and Movement Indication.
In this position the STP73U actuator is de-
energized. The shaft is retracted and the
valve is opened.
In this position the STP73U actuator is
connected to the power supply for at least
4-1/2 minutes. The actuator shaft is
extended and the valve is closed.
Opening and Closing
Times
Figure 3. Opening and Closing Times.