Product Data Sheet
Edition 02
September 2008
Rosemount TankRadar® CTS
Level Unit - LU
Function
The Level Unit (LU) contains terminals for the intrinsically safe connection of the liquefied gas Gauges. It
also contains the electronics used for processing the
signals from the Gauges, for calculating the tank parameters, such as average vapor and liquid temperatures, and for communicating with the Workstation.
The cables from the gauges enters the cabinet
through the bottom of the Level Unit. Up to 20 gauges
can be connected to a Level Unit.
The Level Unit is a cabinet with mainly three different
parts:
• At the bottom, the Power Unit is placed supplying
the cabinet and the equipment on deck with intrinsically safe power.
• In the middle of the cabinet, the Level Interface(s)
are placed. This is where the cables from the
Gauges are connected.
• At the top part of the cabinet, the Calculation Unit
is placed. It contains the boards for processing and
calculation of the measured values. It also contains
the Backup Display with a keyboard. The Backup
Display is used mainly for service purposes.
Electrical Connections
The Level Unit is connected to the ships power supply or optional UPS.
The cabinet and the equipment on deck are supplied
with intrinsically safe power from the Power Unit in
the LU.
Intrinsically Safe Galvanic Isolation
Mechanical Mounting
The Level Unit Gauge interface does not need to be
connected to the system safety earth in order to be intrinsically safe. The board does not use conventional
grounded type zener barriers, i.e. an Intrinsic Safety
Earth is not defined. It has transformers, blocking
capacitors and optocouplers. This achieves an approved high integrity isolation that prevents electrical
surges and overloads.
The LU is placed indoors in a non hazardous and
ventilated area. The LU is bolted to the bulkhead and
floor allowing adequate space around the cabinet and
for a free air circulation.
Product Data Sheet
Edition 02
September 2008
Rosemount TankRadar CTS
®
Technical Specification
Cable from LU to Gauge
Level Unit (LU)
Dimension
550 x 1200 x 300 mm
(Width x Height x Depth)
Weight (typical)
60 kg
Power supply
115 VAC +10 to -15%,
45-66 Hz or 230 VAC +10
to -15%, 45-66 Hz
Power consumption
Maximum 200 W for
standard LU with 10
Gauges connected
Cable type
Multicore, 4 x 2 twisted
wire cable with common
screen to each Gauge
Lead area
0.50 - 1.5 mm2
Outer diameter
10 to 25 mm
Cable length
Maximum 400 m
Operating temperature 0 to 55 °C
Cable from LU to I/O Box
Connection to Workstation
RS-485
Cable type
Two twisted pair with
common shield
Explosion protection
Associated apparatus for
non hazardous location:
[EEx ia] IIC T4 (provides
intrinsic safety for equipment in hazardous location)
Lead area
0.50 - 1.5 mm2
Outer diameter
Maximum 18 mm
Cable length
Maximum 400 m
The Emerson logo is a trademark and service mark of Emerson Co. Rosemount TankRadar and the Rosemount logotype are registered trademarks of Rosemount
Tank Radar AB. All rights reserved. The content of this publication are presented for information purposes only, and while efforts have been made to ensure their
accuracy, they are not to be construed as warranties or guarantees, expressed or implied, regarding the products or services described herein or their use or applicability. All sales are governed by our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications
of our products at any time without notice. Rosemount Tank Radar AB accepts no responsibility for any errors that may appear in this publication.
This product is developed and managed by:
Emerson Process Management
Marine Tank Management
Rosemount Tank Radar AB
Box 13045
SE-40251 Sweden
T +46 31 337 00 00
F +46 31 25 30 22
© 2008 Rosemount Tank Radar AB.
For global contacts:
www.EmersonProcess.com/mtm