Flowserve NRG211-1 Level Probe - Manual (Page 18)

18
Annex
Fault finding list
Warning
The terminal strip of the NRS 2-4 / NRS 2-5 is live during operation. This
presents the danger of electric shock.
Cut off power supply before inserting or removing the 19" slide-in unit and
before undertaking any installation or maintenance work.
Green LED
OPERATION
at level switch NRS 2-4 / NRS 2-5 is not illuminated
Fault: The supply voltage has failed.
Remedy: Measure the voltage across A/C28 and A/C30 of the NRS 2-4 / NRS 2-5.
Check power supply and wiring.
No function when level falls or rises – LED
MALFUNCTION IN PROBE
and
HIGH LEVEL
on level switch NRS 2-4 or
LOW LEVEL
on level switch NRS 2-5
are illuminated
Fault: The locking screw has not been removed from the level probe NRG 211-1.
Remedy: Remove locking screw.
Fault: Defective level probe (defective insulating seal, untight stuffing box)
Remedy: Measure voltage across C18/A18 of NRS 2-4 / NRS 2-5. Measure voltage
across terminals 2 and 3 of the NRG 211-1. If voltage
≥
9 V check probe
supply cable and wiring.
No function when level falls or rises – LED
MALFUNCTION IN CABLE
on level switch
NRS 2-4 / NRS 2-5 is illuminated
Fault: Malfunction in probe supply cable (short circuit, interruption).
Remedy: Measure voltage across C18/A18 of NRS 2-4 / NRS 2-5. Measure voltage
across terminals 2 and 3 of level probe NRG 211-1. If voltage
≤
1 V check
probe supply cable and wiring.
Level switch NRS 2-4: No function when level falls or rises or when high level
is exceeded – only the green LED
OPERATION
of the level switch NRS 2-4 is
illuminated
Fault: Level probe does not enter the liquid.
Remedy: Measure voltage across C18/A18 of NRS 2-4. Check installation of
NRG 211-1 and measure voltage across terminals 2 and 3. If necessary
change position of installation of the level probe.
Fault: Defective level switch.
Remedy: Measure voltage across C16/A18 (supply voltage for level probe) on
NRS 2-4. Replace level switch if no voltage can be measured.
Fault: Defective preamplifier.
Remedy: Measure voltage across C18/A18 of NRS 2-4. Measure supply voltage
across terminals 1 and 3 of NRG 211-1 and measuring voltage across
terminals 2 and 3. If supply voltage = 12 V and no measuring voltage can
be measured, replace preamplifier.