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1
INTRODUCTION
The electronic transmitters CP420L and CH420L are designed to work with flowmeters
series COVOL and turbines series TM. The instruments are supplied already configured for
the type of input.
The circuit is based on a microprocessor that, in function of the k factor (pulses per litre)
programmed, calculates the flow rate and totalizes the volume that flows through the meter
and shows these values on a local indicator. The measuring units can be programmed.
The CH420L differs from CP420L in that it is also HART protocol compatible.
2
MODELS
C
3
ELECTRICAL CONNECTION
For the electrical installation it is recommended to use multiple conductor cables with
individual cable sections in the order of 0.25 to 0.5 mm
connect.
In some cases, susceptible to interference, it will be necessary to use shielded cable.
In the model CP ... CH420L, before starting the electrical installation, check that the PG9
cable gland is the right size for the cables to be used. This will guarantee the instrument will
stay watertight. The cable gland is for cables with outside diameters between 3.5 and 7 mm.
To connect the cables, peel the outer insulation to free the inner cables. It is recommended
to tin the ends of the wires to avoid loose ends. Finally, screw down in the corresponding
positions of the terminal strip.
To help in the wiring of the equipment, the description of the terminals is marked on the
printed circuit next to each terminal strip.
Before starting the connection of the equipment, check that the supply voltage available is
the same as marked on the label of the instrument.
3.1
Power supply and analog output
The positive terminal of the power supply is connected to the position + and the positive
terminal of the load to the position -. The negative terminals of the power supply and the
load are connected together. Since it is a 2-wire instrument, the supply and signal line is the
same. It is recommended to use a twisted pair wiring or shielded cable to avoid interferences
in the current loop.
In the CP ... CH420L, the 4-20 mA loop is connected to the screw terminal strip located
below the keys on the opposite side of the printed circuit board. The terminal on the right is
the positive (+) and the terminal on the left is the negative (-).
In the CP ... CH420R, the transmitter is provided with two terminal strips.
The connection of the 4-20 mA loop must be done according to the figure.
-
420
-
-
C
T
L
Local mounting on flowmeter (IP65)
R
DIN rail mounting inside a de un cuadro
P
Transmitter with analog output
H
Transmitter with analog and HART communication
COVOL input
TM input
4
2
in order to make it easier to
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