17
6 Setup with the integrated display and adjustment unit
SU 600 Ex • 4 … 20 mA signal conditioning instrument
30653-EN-150129
tion. The complete measuring range will be shifted by the deviating
amount.
1. Make sure that the pressure transmitter is completely unpressur-
ised, uncovered (unimmersed) and mounted in its final position.
2. Set the function switch to position [
A
]. The display indicates now
the actual sensor current in mA. Save the current status by push-
ing the [
+/-
] keys simultaneously.
For this adjustment procedure, two sensor current values
(4 … 20 mA) must be entered corresponding to the levels 0 % and
100 %.
When using a pressure transmitter, an offset correction should be car-
ried out to reach maximum accuracy. Carry out this offset correction
before adjustment and with the sensor uncovered (unimmersed).
→
Now select the position [
D
] or [
E
] on the function switch, enter the
current values in mA for min. or max. adjustment and save your
settings.
During this adjustment procedure, the current level is assigned to
a certain percentage value. For this reason, percentage values that
correspond to the actual filling levels must be entered for the min. and
max. adjustment. The ideal calibration is at 0 % and 100 %. Because
it is not always possible to empty or fill a vessel completely, any value
can of course be entered. The greater the difference between the two
adjustment points, the more precise the measurement. It does not
matter which value is entered first.
→
Select position [
B
] or [
C
] on the function switch, enter the per-
centage values for the min. and max. adjustment and save your
settings.
Two operating relays are integrated inSU 600 Ex for level detection.
First of all, determine at which switching points the relays should
switch on and off again. Furthermore you have to distinguish between
the relay modes overfill and dry run protection. You switch over by
exchanging the ON/OFF values of the relay.
•
Overflow protection
: Relay is switched off when the max. level is
exceeded (safe currentless state), relay is switched on again when
the level falls below the min. level (switch-on point < switch-off
point)
•
Dry run protection
: Relay is switched off when the level falls
below the min. level (safe currentless state), relay is switched on
again when the max. level is exceeded (switch-on point > switch-
off point)
→
To adjust the on and off switching points of relay 1, set the func-
tion switch to position [
1
] or [
2
], enter the switching points for ON
or OFF and save your settings. If necessary, proceed in the same
way with relay 2 (position [
3
] or [
4
]).
Adjustment in mA without
changing the level
Adjustment in % by
changing the level
Relay outputs