Danfoss AKS 41 Liquid Level Transmitter
Publication 9-45
Section 9
Page 8 of 18
Issue 1 : 10/11
6.
Adjustment
6.1.
Setting for the Refrigerant
The AKS 41/AKS 41U will not need setting if is used with R717
(ammonia) or R718 (water) and the length of the transmitter corresponds
to the actual refrigerant measured range.
For refrigerants R22, R404a, R134a and R744, set the AKS 41/AKS 41U
for the refrigerant as follows; refer to Fig 4. This procedure can be
carried out before the transmitter is mounted on the plant.
(a)
Dismantle the cap on the DIN connecting plug and pull it back a
little on the cable to gain access to the four screw terminals inside
the plug where the four wires are connected. Connect a meter
between terminals 2 and 3 so that the 4 to 20 mA output signal can
be measured.
(b)
Enter setting mode by removing the DIN plug so there is no voltage
to the level transmitter.
Press the calibration push-button and keep it depressed while
refitting the connecting plug. Release the push-button; the green
LED is extinguished until the push-button is released.
NOTE: this sequence must be observed. Restoring the
supply before the push-button is pressed will change
the signal damping.
(c)
When the push-button is released, observe the green LED number
of flashes and the 4 to 20 mA output signal; refer to Fig 4.
(d)
Press the calibration push-button to select the refrigerant. Each
press steps to the next refrigerant according to the table in Fig 4.
When the measured output current corresponds to the required
refrigerant, wait 10 seconds until the green LED is constant
illumination (not ‘flashing’). This indicates that the required
refrigerant has been selected.
G
REEN
LED
N
UMBER
O
FF
‘F
LASHES
’
O
UTPUT
S
IGNAL
R
EFRIGERANT
1
5 mA
1
R717 or R718
2
6 mA
R22
3
7 mA
R404a
4
8 mA
R134a
5
9 mA
R744
1
Default (factory setting)
Fig 4 Calibration for the Refrigerant
20 mA
4 mA
43 mm
30 mm
