Wiring Diagrams - Siemens Powermite 599 MT Series Technical Instructions

Technical Instructions
Document Number 155-308P25
March 17, 2015

Wiring Diagrams

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SQS Electronic Valve Actuator, 24 Vac, 3-Position (Floating) Control, Fail-Safe
CAUTION:
Terminals G and 21 must be properly wired for correct function and full
life of the actuator.
If the actuator makes a buzzing noise upon reaching setpoint, G and 21
are improperly wired and should be reversed.
Figure 2. SQS85.53U Terminal Connections.
The valve body assembly determines the action of the complete valve/actuator
assembly as follows:
Normally Closed Valve:
•
When the actuator shaft extends, the valve opens (0 to 1).
•
When the actuator shaft retracts, the valve closes (1 to 0).
Normally Open Valve:
•
When the actuator shaft extends, the valve closes (0 to 1).
•
When the actuator shaft retracts, the valve opens (1 to 0).
Three-Way Valve:
• When the actuator shaft extends (0 to 1), the valve opens between
port A and AB.
• When the actuator shaft retracts (1 to 0), the valve opens between
port B and BA.
G, 21 24 Vac operating voltage
G = System neutral
21 = System potential
Y1 Extends actuator shaft
Y2 Retracts actuator shaft
Siemens Industry, Inc.