Toshiba GF630 Manual page 10

GF630/LF620 GF632/LF622
Wiring Precautions
(1) Explosion proof type flowmeters are not
provided cable glands.
Refer to the part Cable connection port at
detector and converter.
(2) Connect the grounding wire (IV wire 5.5mm² or
more) to a good earth ground (100Ω or less
ground resistance). Make the wire as short as
possible. Do not use a common ground shared
with other equipment where earth current may
flow. An independent earth ground is
recommended.
(3) The allowable cable lengths between the
detector and converter for the separate type
flowmeter depend on the electrical conductivity
of the object fluid. See Figure 8.
(4) DO1, DO2, and DI use the same common
terminal (COM). This COM can not connect to
other equipments which have their own ground
terminal. (Power supply for connecting to DI or
DO, etc...) Need to wire separately.
Wiring Precautions (PROFIBUS
(1) For wiring path, avoid places near electrical
equipment that may cause electromagnetic
induction or electrostatic induction interference
(such as a motor, transformer and wireless
transmitter).
(2) Use a PROFIBUS-PA cable or a RS485
twist-pair cable for signal cable. In addition,
make sure to use a shielded cable to improve
noise resistance. Furthermore, installation of
signal cable in metal conduit is recommended.
(3) General cables are designed for indoor use where
cables are not exposed to humidity, rain, etc.
When you install cables, make sure to check the
operating conditions such as the operating
temperature range of the cable by contacting its
manufacturer.
(4) When you carry out cable end treatment of cable,
use a dedicated cable stripper etc. so that the core
wire of the cable will not be nicked or damaged.
In addition, for cables, be careful of allowable
maximum bend diameter etc. (Basically, do not
install cables in a way cables are twisted or
bent.).
(5) Consider installing a PROFIBUS-PA arrester in
the communication path of PROFBUS-PA so
that the electromagnetic flowmeter will not be
affected by lightning etc.
(6) The electromagnetic flowmeter is not equipped
with terminating resistors.Use the terminating
resistor unit for PROFIBUS-PA or junction box,
if necessary.
10
(7) Only one PROFIBUS-PA cable goes through a
(8) Install a terminator to flowmeter that connected
)
or Modbus
Meter Size
To select the meter size:
Note: Make sure the full-scale flow rate used for the
cable gland of the Electromagnetic Flowmeter.
Use the junction box at system configuration
to end of Modbus network.
300
200
100
50
30
20
10
5
3
3 5
Conductivity (µS/cm)
Figure Figure Figure 8 8 8 8 . . . . Electrical Conductivity and Figure Electrical Conductivity and Electrical Conductivity and Electrical Conductivity and
Cable Cable Cable Cable Lengt Length h h h Lengt Lengt
See Table 2 to 3 and find meter sizes within the
velocity of 0.1 to 10m/s for a specified full-scale
(measuring range high limit) flow. Select one that
has its full-scale velocity between 1 and 3m/s.
final planning stage stays within 10m/s in terms
of flow velocity.
.
10 20 30 50 100 200