BERTHOLD TECHNOLOGIES LB 480, User Manual

Page: 163 / 450

SENSseries LB 480 Level measurement
BERTHOLD TECHNOLOGIES GmbH & Co. KG
2 – 163
Volume 2 1 System Description
2
Current output
HART current output 4 ... 20 mA, floating
passive or active (Source or Sink mode)
Resolution better than 6µA
Impedance range active: 120 ohms to 500 ohms
Passive impedance range: up to 250 ohms at 12V, 500 ohms at
24V.
For safe HART
®
communication you need at least 250 ohms.
The maximum cable length of the
HART
®
loop depends on the con-
nected impedance as well as on the capacity and inductivity of the
cable.
Max. cable length with BERTHOLD cable # 32024:
– 3300 m at 120 ohms
– 1600m at 250 ohms
– 800m at 500 ohms
The current output itself is monitored continuously and, in case of
malfunction, signals 24 mA constantly via a redundant current path.
The digital HART
®
communication remains in effect even on the
redundant current path.
For intrinsically safe signal output see Volume 1, chapter 5, "Explo-
sion Protection".
Power supply
Nominal voltages (depending on version):
100V to 240V
AC
±10%, 50/60Hz, max. 8VA or
24V
DC
(18 to 32V
DC
), max 8W
Cable conduits
4 cable conduits with M20 (ATEX) or ½" NPT (FM/CSA) for process
connection, closed with dummy plugs. The screw fittings which are
not needed for the installation must be closed with sealing plugs
that are suitable for the type of protection, see
page 2-290 .
Cable glands
The screw fittings supplied by BERTHOLD TECHNOLOGIES match
the protection type IP66, IP68 and IP69K. The permitted cable
cross-section of the screw fittings is listed in our offer or our order
confirmation.
The screw fittings are enclosed for each specific order, and, depend-
ing on the type, they may be nickel-plated brass (standard) or
stainless steel.
Current output
passive active Signal output
LB 480-xx-0x LB 480-xx-Zx Non-Ex
LB 480-xx-1x LB 480-xx-2x Ex-e
LB 480-xx-3x LB 480-xx-4x intrinsically safe