Flowserve NRS1-8 - Manual (Page 14)

4
Wiring
NRS 1-8
Cable required for wiring to the electrode: four-core screened cable, e. g. I-Y(St)Y  x  x 0.8 or
LIYCY 4 x 0.5².
Max. cable length 00 m with a conductivity from 0 μS/cm.
Max. cable length 30 m with a conductivity from 0.5 μS/cm.
Max. cable length 5 m with a conductivity from 0.5 μS/cm when used in conjunction with inverter
URN  (4 V d. c.)
Tools
n
Screwdriver for slotted screws, size .5, completely insulated according to VDE 0680-.
Voltage table
Use this voltage table as reference when checking the level electrode for malfunction or submersion.
Take the wiring diagram (see Fig. 10, Fig. 11) into account.
Attention
n
To protect the switching contacts provide the circuit with a .5 A slow-blow fuse or
according to TRD regulations (.0 A for 7 hrs operation).
n
The screen must not make any other electrical contact.
Note
n The self-checking routine of the amplifier NRS -8 reduces U
-
every 40 sec.
down to 0 volt.
n Connect screen only to terminal 8 of the temperature switch.
n The sensitivity is indicated on the name plate.
n
The rated voltage is indicated on the name plate.
n
When switching off inductive loads, voltage spikes are produced that may impair the
operation of control and measuring systems. Inductive loads should therefore be
provided with commercial arc suppressor RC combinations, e. g. 0. μF/00 Ω.
U
-
 V
eff
C=0.3 cm -
0 µS/cm 0.5 µS/cm
U
-
0 V
eff
C=0.3 cm -