33
NRGS 15-1 - USA - Installation & Operating Manual -
850690-00
Attention
Please check the following before fault diagnosis:
Supply voltage:
Is the level switch supplied with the voltage specified on the rating plate?
Wiring:
Does the wiring conform to the wiring diagram?
Fault indications and troubleshooting
Indications, diagnosis and corrective action
MAX level switchpoint
Water below
MAX level
switchpoint,
LED 4 lights up
red.
Electrode rod is too long.
Cut electrode rod to appropriate length for the
switchpoints.
Electrode rod has contact with ground.
Check installation location and change if
necessary.
For internal installation: Upper pressure
relief hole in protective tube is missing
or obstructed.
Check level switch installation and make sure
that the level in the protective tube corresponds
to the actual water level.
MAX level
switchpoint
reached, LED 4
is not lit.
Electrode rod is too short.
Replace level switch and cut electrode rods to
appropriate length for the switchpoints.
Ground connection to tank is inter-
rupted.
Check ground connection and fit band
grounding clamp if necessary (see page 25 for
installation).
Electrical conductivity of boiler water
is too low.
Set response sensitivity to 0.25 ppm
(0.5 μS/cm).
For internal installation: The upper
pressure relief hole is flooded.
Check level switch installation and make sure
that the level in the protective tube corresponds
to the actual water level.
MIN level switchpoint
Status and
display
Error
Corrective action
Water below
MIN level
switchpoint,
LED 1 is not lit.
Electrode rod is too long.
Cut electrode rod to appropriate length for the
switchpoints.
Electrode rod has contact with ground.
Check installation location and change if
necessary.
For internal installation: Upper pressure
relief hole in protective tube is missing
or obstructed.
Check level switch installation and make sure
that the level in the protective tube corresponds
to the actual water level.
A protective tube is required/recom-
mended for internal installation.
MIN level
switchpoint
reached, LED 1
lights up red.
Electrode rod is too short.
Replace level switch and cut electrode rods to
appropriate length for the switchpoints.
Ground connection to tank is inter-
rupted.
Check ground connection and fit band
grounding clamp if necessary (see page 25 for
installation).
Electrical conductivity of boiler water
is too low.
Set response sensitivity to 0.25 ppm
(0.5 μS/cm).
Difference in level between water in the
boiler and the protective tube (internal
installation).
Check level switch installation and make sure
that the level in the protective tube corresponds
to the actual water level.
For internal installation: The upper
pressure relief hole is flooded.