44
1. Fill steam boiler or vessel with liquid until the lower measuring point is reached.
2. Raise the pressure in the steam boiler or vessel until the service pressure is reached.
3. Turn potentiometer
f
to the left until the red LED
g
lights up.
4. Turn potentiometer
f
to the right until
only
the green LED
h
lights up.
The lower measuring point is now adjusted.
Adjusting lower measuring point NRGT 26-1S
Commissioning Procedure
EN
Danger
1. Make sure that the NRG 16-11 and NRGT 26-1 are wired in accordance with the wiring diagram.
Fig. 10, Fig. 13, Fig. 14
2. Make sure that the supply voltage agrees with the specification on the name plate.
The terminal strips of the level transmitter NRGT 26-61S are live during operation.
This presents the danger of electric shock!
Always cut off power supply to the equipment before mounting, removing or connecting
the terminal strips!
Use only a completely insulated screwdriver according to VDE 0680 for setting the
measuring points.
Checking electrical connection
1. Switch on supply voltage. The LED
g
of the electrode NRGT 26-1 lights up (exposed condition).
Fig. 8
Switch on supply voltage
1. Fill steam boiler or vessel with liquid until the upper measuring point is reached.
2. Turn potentiometer
j
to the right until
only
the red LED
i
lights up.
3. Turn potentiometer
j
to the left until the green LED
h
lights up.
4. Turn potentiometer
j
to the right until the green LED
h
goes out.
The upper measuring point is now adjusted.
5. Mount housing cover
d
.
Adjusting upper measuring point NRGT 26-1S
Note that if the measuring points of the electrode NRGT 26-1S are set when the system
is
cold
, the measuring points will shift due to longitudinal expansion of the electrode rod
when the system gets hot.
Correct the settings accordingly.
If a higher accuracy (for 0% = 4 mA and 100% = 20 mA) than ± 0.5 mA is required,
measure the level-proportional current at terminals 1 (–) and 2 (+) in order to establish
more accurate settings.
Note
