KROHNE SU 600, Operating Instructions Manual

15

6 Setup with the integrated display and adjustment unit

SU 600 • 4 … 20 mA signal conditioning instrument

30652-EN-150129

measuring transducers without separate operating voltage (sensor 

in two-wire version).

• 

In passive mode, the sensors are not powered, only the measure-

ment value is transmitted. This mode is provided for connection of 

transmitters with their own separate operating voltage (sensors in 

four-wire version).

→ 

Set the function switch to position [

F

] and select the suitable 

mode with the [

+/-

] keys. Save your settings by pushing both keys 

simultaneously.

When a pressure transmitter is used, an offset correction should be 

carried out first. These instruments are factory-set in a certain posi

-

tion. If the pressure transmitter is now mounted in a different position, 

its measuring range is shifted slightly. The zero point is readjusted by 

carrying out the offset correction in uncovered (unpressurised) condi

-

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 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.

Offset correction

Adjustment in mA without 

changing the level

Adjustment in % by 

changing the level

Relay outputs