11
NRS 1-52 - Installation Instructions -
819176-02
In control cabinet: Wiring level switch
- continued -
Connecting supply voltage
The equipment is supplied with 24 V DC and fused with an external semi-delay fuse 0.5 A.
Please use a power supply unit with safe electrical isolation.
The power supply unit must be electrically isolated from dangerous contact voltages and must meet at
least the requirements on double or reinforced isolation according to one of the following standards:
EN 61010-1, EN 60730-1, EN 60950-1 or EN 62368-1.
Connecting level electrode
To connect the level electrode(s) use screened multi-core control cable with a min. conductor size
0.5 mm
2
, e. g. LiYCY 3 x 0.5 mm
2
, max. length: 100 m.
Wire terminal strip in accordance with the wiring diagram.
Fig. 3
.
Connect the screen
only
once
to the central earthing point (CEP) in the control cabinet.
Make sure that connecting cables leading to the level electrodes are segregated and run separately
from power cables.
Tools
n
For all functions: Screwdriver 0.8 x 4.0 or 0.8 x 4.5.
Connecting MIN/MAX output contact
Wire the upper terminal strip
1
(terminals 16-18, 21-23) according to the desired 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 opera-
tion of control and measuring systems.
Connected inductive loads must be provided with suppres-
sors such as RC combinations as specified by the manufacturer.
Attention
n
Do not use unused terminals as support point terminals.
