TIC-LF654L
11
Wiring Precautions
(1) Explosion proof type flowmeters are not provided
with 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 (100 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 10.
(4) DO1, DO2 and DI use the same common terminal
(COM). This COM can not be connected to other
equipment which have their own ground terminal.
(Power supply for connecting to DI or DO, etc…)
Need to wire separately.
Wiring Precautions (PROFIBUS or
Modbus)
(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 twisted-pair
cable for signal cable.
In addition, make sure to use a shielded cable to
improve noise resistance. 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, use a
dedicated cable stripper to avoid the core wire of the
cable being nicked or damaged. In addition, for
cables, be careful of allowable maximum bend
diameter. (Do not allow excessive twisting or
bending of cables).
(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.
(7) Only one PROFIBUS-PA cable goes through a
cable gland of the Electromagnetic Flowmeter.
Please use the junction box at system configuration
.
(8) Install a terminator to flowmeter that connected to
end of Modbus network.
300
200
100
3
5
10
30
50
3 5 10 2030 50100200
Conductivity (
S/cm)
Allowable cable length (m)
20
Figure 10. Electrical Conductivity and Cable
Length
Meter Size
To select the meter size:
See Table 2 and 3 to find meter sizes within the velocity
of 0.3 to 39.4 ft/s (0.1 to12m/s) for a specified full-scale
(measuring range high limit) flow. Select one that has
its full-scale velocity between 3.0 and 10 ft/s (1 and
3m/s).
Note: Make sure the full-scale flow rate used for the final
planning stage stays within 39.4ft/s (12m/s) in terms of
flow velocity.
Table 2. Flow Rate and Flow velocity
(English unit)
Unit: gal/min
Size
(inch)
Flow rate
0.328 ft/s 0.98 ft/s 3.0ft/s 10 ft/s 39.4 ft/s
1/2' 0.2801 0.8403 2.561 8.532 33.61
1 0.7781 2.334 7.115 23.72 93.37
1 ¼ 1.275 3.824 11.66 38.86 153.0
1 ½ 1.992 5.975 18.21 60.71 239.0
2 3.112 9.337 28.46 94.86 373.5
2 ½ 5.260 15.78 48.09 160.3 631.2
3 7.967 23.90 72.85 242.8 956.1
4 12.45 37.35 113.8 379.4 1,494
5 19.45 58.35 177.9 592.9 2,334
6 28.01 84.03 256.1 853.8 3,361
8 49.80 149.4 455.3 1,518 5,975
10 77.81 233.4 711.5 2,372 9,337
12 112.0 336.1 1,025 3,415 13,445
14 152.5 457.5 1,394 4,648 18,300
16 199.2 597.5 1,821 6,071 23,902
18 252.1 756.3 2,305 7,684 30,251