Fail-Safe Action; Cover Screws; Additional Functions - Samson 5824 Mounting And Operating Instructions

3.1 Fail-safe action

The actuator moves to the fail-safe position
when the electromagnet is de-energized. This
causes the actuator stem to be completely re-
tracted or extended by the spring mecha-
nism.
The Type 5825 Actuator is available with the
fail-safe action:
Actuator stem extends: Upon power supply
failure, the actuator stem extends.
Actuator stem retracts: Upon power supply
failure, the actuator stem retracts.
Î The fail-safe action must not be used to
control the valve position.
The Type 5825 Actuator does not have a
handwheel (2) on the housing cover. Manual
override is possible, after removing the front
cover, using a 4 mm Allen key. The actuator
returns to its original position as soon as the
Allen key is released.
Testing according to DIN EN 14597
The Types 5825 Electric Actuator with fail-
safe action "actuator stem extends" is tested
by the German technical surveillance associ-
ation (TÜV) according to DIN EN 14597 in
combination with various SAMSON valves.
The register number is available on request.
EB 5824-2 EN
Design and principle of operation

3.2 Cover screws

The actuator housing cover is fastened using
TORX PLUS screws, size 10IP.
®
Î To loosen and tighten the screws, the fol-
lowing screwdrivers can be used:
− TORX T10
®
− TORX PLUS 10IP
®
− Flat-blade screwdriver with 0.8 mm
blade thickness and 4.0 mm blade width

3.3 Additional functions

Devices in 24 V version can be fitted with
limit contacts as additional function:
− On request, the actuators can be fitted
with two limit contacts. Optionally, the
actuators can be equipped with two limit
contacts, which are actuated by continu-
ously adjustable cam disks.
− The power supply as well as the inputs
and outputs are not galvanically isolated.
− The two additional limit contacts are not
suitable for retrofitting.
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