Flowserve NRS 1-7 - Manual (Page 16)

16
Apply mains voltage to level switch NRS 1-7.
Commissioning
Check that the NRS 1-7 and the associated level electrode are wired in accordance with the wiring
diagram, Fig. 10, Fig. 11.
Checking wiring
Apply mains voltage
Performance test
1. Check length of electrode rod (see installation manual of the level electrode).
2. When switching on the mains voltage the green LED 4 should be permanently illuminated, Fig. 7.
3. Completely open valves of water-level gauge glass on steam boiler.
4. Fill boiler with feedwater (2 cm above required level).
5. Decrease level in boiler until the level falls below low level. After the response delay indicated on
the name plate the two red LEDs 2 on the level switch must light up.
If the automatic self-checking test is initiated during this phase an alarm will only be raised after
twice the nominal delay period.
6. A low-level alarm can be simulated by pushing the button “TEST 1” 3 with the electrode tip
submerged. Push the button until the response delay has expired. Both red LEDs 2 must light up.
7. The checking circuitry of the level switch can also be checked. Operate switch “TEST 2/Inspection”
1 in the direction of the arrow with the electrode tip submerged. After max. two minutes the two
red LEDs 2 should signal low-level alarm. The button “TEST 1” 3 must not be operated during
this test nor must the level fall below the low level mark.
After the test return switch 1 into its original position. After the response delay the two red LEDs
2 must extinguish.
Low-level limiter