Siemens 6DR55 Series Manual page 34

Design and method of operation
Installation
.
Opening the
instrument
.
32
The option modules are secured by a assembly covering ((1), see fi-
gure 16, page 33) and mechanically fixed.
NOTE
The housing must be opened to install the options modules. The
degree of protection IP66 is not guaranteed as long as the positioner is
open.
To open the positioner, the four screws of the housing cover must be
loosened with a Phillips screwdriver.
Disconnect or isolate the power supply cables.
Remove the module cover (1). To do this, the two screws (1.1) must be
removed with a screwdriver.
NOTE
To prevent premature wearing of the fixture by the self--tapping screws
(1.1), the following method of mounting the module cover (1) has
proven effective.
1. Turn the screws counterclockwise until you feel them snap into the
thread
2. Tighten both screws carefully in clockwise direction
SIPART PS2 PA Manual
A5E00127926--05