16
In control cabinet: Wiring the level controller / the operating & display unit
Connection of supply voltage
The level controller and the operating unit are supplied with 24 V DC each and provided with an internal
(URB) or external fuse (NRR 2-5.., semi-delay 0.5 A). The devices are separately supplied with 24 V DC
and provided with an external semi-delay fuse 0.5 A. Please use a safety power supply unit with safe
electrical isolation. The power supply unit must be electrically isolated from dangerous contact volta-
ges and must meet at least the requirements on double or reinforced isolation according to one of the
following standards: DIN EN 50178, DIN EN 61010-1, DIN EN 60730-1 or DIN EN 60950.
After switching on the supply voltage and start-up of the equipment the LED of the level controller
NRR 2-52, NRR 2-53 lights up green.
Connecting level electrode, level transmitter
To connect the equipment use screened multi-core control cable with a min. conductor size 0.5 mm
2
,
e. g. LiYCY 4 x 0.5 mm
2
, max. length 100 m.
Wire terminal strip in accordance with the wiring diagram.
Fig. 7, 8
Wire screen in accordance with the wiring diagram.
Make sure that connecting cables leading to the equipment are segregated and run separately from
power cables.
Connecting output contacts
Wire the upper terminal strip
8
(terminals 16-23) according to the desired and ordered switching
functions. Provide an external slow-blow fuse 2.5 A for the output contacts.
When switching off inductive loads, voltage spikes are produced that may impair the operation of control
and measuring systems. Connected inductive loads must be provided with suppressors such as
RC combinations as specified by the manufacturer.
Attention
n
Do not use unused terminals as support point terminals.
Connecting the potentiometer (for indication of valve positions), connections IN ../ OUT / 4-20 mA
To connect the equipment use screened multi-core control cable with a min. conductor size 0.5 mm
2
,
e. g. LiYCY 2 x 0.5 mm
2
, max. length: 100 m.
Please observe the max. load of 500 ohm for the outputs.
Wire terminal strip in accordance with the wiring diagram.
Fig. 7, 8
Connect the screen
only once
to the central earthing point (CEP) in the control cabinet.
Make sure that connecting cables are segregated and run separately from power cables.
Connection of data line for the level controller / operating & display unit
For connecting the equipment preconfigured control cable assemblies (with female connector) are
available as add-on equipment. Wire terminal strip in accordance with wiring diagram.
Fig. 7, 8
If you do not use the above-mentioned control cable assembly, use screened multi-core control cable,
e. g. LiYCY 2 x 0.25 mm
2
, conductor size 0.25 mm
2
, max. length 30 m.
Wire the terminal strips according to the wiring diagram
Fig. 7, 8.
Wire the 9-pole D-SUB connector
according to
Fig. 11.
Connect the earthing point of the housing (URB 50) to the central earthing point in the control cabinet.
Connect the screen
only once
to the central earthing point (CEP) in the control cabinet. Make sure that
connecting cables leading to the equipment are segregated and run separately from power cables.
Summary of Contents for NRR 2-52
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