16
EP100 Master Instruction
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D00002-C-04
7.8 Air reducing throttles
Attention: Service only
Air flow to the actuator may be reduced via air
reducing throttles
17
and
18
.
Ex-factory the air capacity is non-throttled;
generally, this is the most favorable setting. In the
non-throttled condition the screw head is even with
the amplifier surface. Since the flatness of the
screw heads is not visible in the installed
electronics, the basic setting can be restored as
follows:
turn off air supply
carefully turn air reducing throttle screw
clockwise until impact, thereafter 5 complete
return rotations (counterclockwise)
restart air supply
Reducing of output air capacity
Attention: Service only
Output air capacity may be reduced in exceptional
cases only in small volume actuators with a small
spring range if after optimization of the control still
oscillating tendency exists (amplification of control
loop is too high). For this purpose turn air reducing
throttle screws
17
and
18
to a maximum of 5
rotations clockwise.
Caution:
Amplifier may be damaged if a loud
noise can be heard from amplifier resulting from
too strong reducing. Immediately turn back
throttles significantly!
7.9 Basic adjustment of electronics
Attention: Service only
The electronics unit has been sufficiently factory-
adjusted; an adjustment at delivery is not required.
The potentiometer is secured by means of lacquer
against unintentional operating.
In the event an adjustment of the electronics
becomes necessary (e.g. following exchange of
electronics) the procedure is as follows:
a) Enter input current 4 mA.
b) Switch S3 to “II”: p
ositioner control loop is
opened.
c) Turn potentiometer P1 until actuator just begins
to move from its end position.
d) Return S3 to “I”.
7.10 Pneumatic test
Attention: Service only
To check the pneumatic parts of the positioner by directly
applying current to the IP module (no control).
Procedure: Put switch 8 in position ”II” (see illustration).
Attention!
Resetting of switch 8 initiates actions influencing and possibly
disturbing the current process! Therefore, no medium should
flow through the valve during these settings.
Setting switch 8 to position “II” actuates a pneumatic test
checking the function of the positioners pneumatic system
including its control. If switch 8 is set from position “I”
(condition of operation) to position “II”, the pressu
re in the
actuator goes to nearly air supply pressure. The actuator
moves to the direction associated with maximum pressure.
If no reaction is shown, check:
- does air supply exist?
- is plug connected to IP module?
If these items are okay, possibly the electronics or a
pneumatic part are defect. Exchange see page 18.
During operation switch 8 must be in position “I” at all times!
8 DECOMMISSIONING
Before decommissioning the unit, disconnect supply air and
the electrical input signal.
