Samson 3730 Series Mounting And Operating Instructions page 8

Safety instructions and measures
Personal protective equipment
No personal protective equipment is required for the direct handling of the positioner. Work
on the control valve may be necessary when mounting or removing the device.
Î Observe the requirements for personal protective equipment specified in the valve docu-
mentation.
Î Check with the plant operator for details on further protective equipment.
Revisions and other modifications
Revisions, conversions or other modifications of the product are not authorized by SAMSON.
They are performed at the user's own risk and may lead to safety hazards, for example. Fur-
thermore, the product may no longer meet the requirements for its intended use.
Safety features
Upon failure of the air supply or electric signal, the positioner vents the actuator, causing the
valve to move to the fail-safe position determined by the actuator.
Warning against residual hazards
The positioner has direct influence on the control valve. Any hazards that could be caused in
the valve by the process medium, the signal pressure or by moving parts are to be prevented
by taking appropriate precautions. They must observe all hazard statements, warning and
caution notes in these mounting and operating instructions, especially for installation, start-
up and service work.
If inadmissible motions or forces are produced in the pneumatic actuator as a result of the
supply pressure level, it must be restricted using a suitable supply pressure reducing station.
Explosion protection
− Explosive dust atmospheres of zone 21 or zone 22
The following applies to type of protection Ex i in combustible dust atmospheres:
If intrinsic safety is impaired by the influence of dust, an enclosure complying with
Clause 6.1.3 of EN 60079-11 with at least in degree of protection IP 5X must be used.
The requirements according to Clause 6.1.3 apply to the cable glands accordingly. The
degree of ingress protection is verified by a test according to IEC 60529 and EN 60079-
0 (e.g. performed by VDE).
For use in the presence of combustible dust in compliance with type of protection
Ex tb IIIC (protection by enclosure), observe Clause 5.6.3 of EN 60079-14.
8 EB 8384-6 EN