Behavior In Case Of Failure Of The Electrical Auxiliary Power And/Or The Supply Pressure Pz - Siemens SIPART PS100 Compact Operating Instructions

5.4.2 Behavior in case of failure of the electrical auxiliary power and/or the supply
pressure PZ
Overview
Note the following before working on the control valve
Note that, before working on the control valve, you must first move it to the safety position.
Make sure that the process valve has reached the safety position. If you only interrupt the
supply pressure PZ to the positioner, the safety position can in some cases only be attained after
a certain delay period.
The difference between a failure of supply pressure PZ and a failure of electrical auxiliary power:
• Failure of electrical auxiliary power means the failure of the signal source at the analog
input 4 to 20 mA.
• Failure of the supply pressure PZ
Actuator type
Single-acting
Double-acting
SIPART PS100
Compact Operating Instructions, 05/2021, A5E50188940-AA
CAUTION
Behavior in case of failure: The actuator moves into safety position
Failure of electrical auxiliary power Failure of supply pressure PZ
Y1 = vented
Y1 = pressurized
Y2 = vented
5.4 Pneumatic connection
Y1 = vented
Y1 = closed
Y2 = closed
Connecting
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