ABB LMT Series Operating Instruction page 22

22 L M T 1 0 0 A N D L M T 2 0 0 | M A G N E TO S T R I C T I V E L E V E L T R A N S M I T T E R S | F F O I/ L M T 1 0 0/ 2 0 0/ F F - E N R E V. A
Remote version: Connection to remote
mount design
The signal cable connects the measuring sensor to the
transmitter The cable is fixed to the transmitter, however, it
can be separated as needed
When laying the signal cable, observe the following points:
– Install the signal cable in the shortest path between the
measuring sensor and the transmitter Shorten the signal
cable accordingly as needed
– The maximum permissible signal cable length is 30 m
(99 ft)
– Avoid installing the signal cable in the vicinity of electrical
equipment or switching elements that can create stray
fields, switching pulses and induction If this is not possible,
run the signal cable through a metal pipe and connect this
to operational ground
– Carry out all terminal connections carefully
– Lay the wires in the terminal box in such a way that they are
not affected by vibrations
Remote version: Cutting the signal cable to
length and terminating it
The signal cable is available in four standard lengths: 5 m
(16 4 ft), 10 m (32 8 ft), 20 m (65 6 ft) and 30 m (98 4 ft)
The cable ends are already prepared for installation
Figure 21 Signal cable dimensions in mm (inch)
A
Measuring sensor
B
Transmitter
1 Heat-shrink tube Ø 4 mm, 10 mm long 2 Forked cable lug
3 Heat-shrink tube Ø 2 3 mm, 40 mm long (shielding)
The signal cable can also be cut to any
length . Then the cable ends must be
prepared as below .
– Twist the shield, shorten and insulate with heat-shrink
tube 3 Crimp a matching forked cable lug 2 and insulate the
crimping with a heat-shrink tube 1
– Provide the wires on the measuring sensor side with wire-
end ferrules (0 75 mm2)
– Twist the wires to the transmitter side and solder
Remote version: Connecting the signal cable
DANGER
Danger of explosion if the device is operated with the
transmitter housing or terminal box open!
Before opening the transmitter housing or the terminal box,
note the following points:
• Check that a valid fire permit is available
• Ensure that there is no risk of explosion
• Switch off the power supply and wait for t > 2 minutes
before opening