Data Sheet for Product
6/8
Siem ens Product range overview CE1N2100en
Building Technologies 2017-07-20
Technical notes
NO valves ∂ Fully open when de-energized (normally open).
∂ Valve stem extended.
Radiator valves like VDN.., VEN.., VUN.., VPD.. or VPE.. are usually NO
valves.
NC valves ∂ Closed when de-energized (normally closed).
∂ Valve stem extended.
Small valves like V..P47.. are usually NC valves.
NO function ∂ Actuator stem is retracted when de-energized.
∂ Valve is open.
NC function ∂ Actuator stem is extended when de-energized.
∂ Valve is closed.
The thermostatic RTN.. actuators control the heat demand. They control the water flow
by opening and closing the radiator valves.
∂ With increased heat demand the actuator stem retracts and steadily opens the radia-
tor valve.
∂ With decreasing heat demand the actuator stem extends and steadily closes the
radiator valve.
Radiator valves (NO valves)
STA..
actuator de-energized
∂ VDN.., VEN.., VUN..
∂ VPD.., VPE..
closed (NC function)
Use STA73PR/00.. actuators for DESIGO RX..
The STA63 actuator is driven by a DC 0...10 V. It is uni-directional (Y∀). When used
with NO radiator valves or NC small valves, the STP63 must used in one direction only
(Y#).
Operation Breakdown
Direction
of action
Positioning signal
DC 0…10 V
Actuator
stem
Valve behavior Actuator without operating voltage
∀ STA63 Y∀ increasing
Retracted NO opens NO radiator valve, VD1..CLC small
valve or MCV closed
# STP63 Y# increasing
Extended NC opens NC small valve fully open
NO, NC valves
Valve and actuator
combinations
RTN..
STA..
Attention
STA63