ENGLISH
Wiring
Wiring should be carried out in accordance with
wiring diagram (Fig. 3).
For wiring to the electrode, screened cable,
e. g. 4 x 0.5 mm
2
is recommended, maximum
cable length 100 m.
Design
Plug-in unit in plastic case for installation in
control cabinets. The terminals in the case are
accessible after loosening two screws and un-
plugging the unit from its base. To avoid con-
fusion with other plug-in units of the GESTRA
range, inserts are fitted in the bases so that
only the correct unit may be plugged into each
base.
The plug-in units may be snapped onto a 35
mm supporting rail or screwed into position on
a mounting panel.
Field enclusures for several plug-in units are
available on request.
Installation of Level Controller
On supporting rail
(with mounting clip)
1. Snap level controller onto supporting rail.
2. Loosen cover screws and unplug
cover from its base (see Fig. 1).
3. Select cable entry and remove cor-
responding seal.
On mounting panel
1. Loosen cover screws and unplug
cover from its base (see Fig. 1).
2. Unscrew mounting clip .
3. Drill the hole marked in the base to
4.3 mm dia.
4. Fasten base with two M4 screws onto
mounting panel.
5. Select cable entry and remove cor-
responding seal.
No user serviceable parts are containes within
the equipment. All repairs must be performed
only by the manufacturer. Misuse or any at-
tempted modification of the equipment will lead
to considerable safety risks!
Important Safety Notes
Technical Data
Input
Four connections for 3 electrode tips.
Output
One volt-free working contact for the controller,
one volt-free relay contact for the alarm;
max. contact rating: 250 V, 500 W, 3 A resistive
with a life of 4 x 10
5
switching cycles or 0.35 A
inductive with a life of 2 x 10
6
cycles;
contact material silver, hard-gold plated.
Sensitivity
Standard design: 10 µS/cm
Special design: 0,5 µS/cm
Electrode supply voltage
11 V AC, free from DC voltage
Indicators and adjustors
ONE LED “Pump ON”, 1 LED “MAX/HW”,
one switch for selection of operation “Feed” or
“Drain” control,
one “Test” button for simulating “high-level
alarm” (HW)
Mains supply
24 V, 110 V, 120 V, 220 V, 240 V, 50 . . . 100 Hz,
3,5 VA,
24 V DC supply also possible with the ancillary
unit type URN-1.
Protection
IP 40
Permissible ambient temperature
0 . . . 50 °C
Case materials
Base: ABS plastic, black
Cover: polystyrene (highly shock-resistant),
stone grey
Approx. weight
0.8 kg
Dimensions
See Fig. 1.
■
Connect screen only to terminal 12 of the
level controller, but not at the electrode.
■
The screen must not make any other elec-
trical contact.
■
The mains voltage is indicated on the name
plate.
Important Notes
Purpose
On-off feedwater control and high-level alarm
for use in conjunction with the GESTRA mul-
tiple level-control electrode type
ER 5 . . .
or
level control electrodes type
ER 16
.
Performance Tests
1. Ensure that electrode tips are completely
exposed from the water surface.
2. Set switch on position “Feed pump”.
3. The LED “Pump ON” must light up.
4. When switching to “Drain Pump”, the LED
“Pump ON” must extinguish.
5. Fill vessel with water up to the high-level
mark.
6. With the switch in position “Feed pump”,
the LED “MAX/HW” must light up.
7. With the switch in position “Drain pump”,
the LED “Pump ON” must light up.
8. The operation of the level controller can
be checked with the aid of the button “Test
HW” .
After pushing this button, the LED “MAX/
HW” must light up.
With the aid of the Electrode Simulation Set
ER 5-S the performance test of the level
controller is made easier.
Fault Finding
Fault A:
The level controller signals MAX/HW
alarm before the level in the vessel has reached
the high-level mark
.
Remedy:
Check length of electrode tips. Check
correct wiring of level controller and electrodes
in accordance with wiring diagram, Fig. 3.
Fault B:
The LED “MAX/HW” does not light up,
although the switch is in position “Feed pump”
and the electrodes are completely submerged.
Remedy:
Check correct wiring of level controller
and electrodes in accordance with wiring dia-
gram, Fig. 3.
If the electrode is installed in a boiler external
level pot, check position of isolating valves.
Fault C:
The LED “MAX/HW” does not light up
although the electrodes are completely sub-
merged.
The feed pump is not switched off. The drain
pump is not switched on.
Remedy:
Determine the conductivity of the
liquid to be monitored. The minimum conduc-
tivity required is
10 µS/cm
for the standard
design and
0.5 µS/cm
for the special design
(see name plate).
Check whether electrode has been sealed off
with Teflon tape, if so, remove tape and use the
ring joint supplied with electrode.
Clean electrode tips.
It fault occur that are not listed above
please contact our subsidiary or agency in
your country.
■
Before unplugging the level controller NRS
1-5b, cut off power supply to base.
■
When replacing level-control electrode
check switchpoint of level controller.
■
When switching of inductive loads, voltage
spikes are produced that may impair the
operation of control and measuring systems.
We therefore recommend that inductive
loads are provided with commercial arc
suppressor RC combinations, e.g. 0.1 µF/
100
Ω
.
Important Notes
B
A
C
B
A
D
C
D
F
E
1
1
2
3
3
4
1
Содержание NRS 1-5b
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