Interconnection; Signal Amplifier/Power Supply; Connecting The Lc 300 - Siemens sitrans lc 300 Instruction Manual

Interconnection

Signal Amplifier/Power Supply

The SITRANS LC 300 uses a switched power supply circuit that makes the most efficient
use of the available power present on the terminals. If the signal current is low (4 mA),
the terminal voltage will increase due to a voltage drop of other components in the loop,
and if the signal current is high (20 mA), the terminal voltage will decrease.
Loosen the lid clip and remove the enclosure cover to access connectors and electronics.
The identification label is on the inside of the enclosure.
ORANGE (S)
BLACK (0)
RED (+)
for factory
FOR FACTORY
software update
SOFTW ARE
UPDA TE USE ONL Y
use only
menu/function
MENU/FUNCTION
selector
SELECTOR

Connecting the LC 300

1. Loosen the retaining lid clip and remove the enclosure cover.
2. Loosen the cable gland and thread the cable through it.
3. Connect the power/signal conductor wires to the current-loop terminal blocks (any
polarity). The loop voltage must be between 9 and 32 Vdc.
4. Ground the enclosure by connecting the housing and the process connection with
either the stilling well and/or the tank wall, using the ground lug near the bottom of
the housing.
5. Check that all connections are secure.
6. Replace enclosure cover and tighten retaining lid clip.
WARNING:
measurement module, providing the supply voltage and receiving the frequency
signal from the measurement. The user should not alter these connections.
Page 14
K1
SENSOR
B1
0
S1
up / + button
UP/+ BUTTON
The sensor terminal block connects the electronics to the
SITRANS LC 300 – INSTRUCTION MANUAL
K3
B2
down / - button
DOWN/- BUTTON
4-20 mA (2-wire)
CURRENT -LOOP
current-loop
SIGNAL
measurement signal
7ML19985HE01