Toshiba LF410 Manual

EJL-136F12 Wiring Precautions(1) Explosion proof type flowmeters are not providedcable glands.Refer to the part Cable connection port at detectorand converter.(2) Connect the grounding wire (IV wire 5.5mm² ormore) to a good earth ground (100Ω or less groundresistance). Make the wire as short as possible. Donot use a common ground shared with otherequipment where earth current may flow. Anindependent earth ground is recommended.(3) The allowable cable lengths between the detectorand converter for the separate type flowmeterdepend on the electrical conductivity of the objectfluid. See Figure 12.(4) DO1, DO2 , and DI use the same common terminal(COM). This COM can not connect to otherequipments 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 electricalequipment that may cause electromagneticinduction or electrostatic induction interference(such as a motor, transformer and wirelesstransmitter).(2) Use a PROFIBUS-PA cable for signal cable. Inaddition, make sure to use a shielded cable toimprove noise resistance. Furthermore, installationof signal cable in metal conduit is recommended.(3) General PROFIBUS-PA cables are designed forindoor use where cables are not exposed tohumidity, rain, etc. When you install cables, makesure to check the operating conditions such as theoperating temperature range of the cable bycontacting its manufacturer.(4) When you carry out cable end treatment ofPROFIBUS-PA cable, use a dedicated cablestripper etc. so that the core wire of the cable willnot be nicked or damaged. In addition, for cables,be careful of allowable maximum bend diameteretc. (Basically, do not install cables in a way cablesare twisted or bent.).(5) Consider installing a PROFIBUS-PA arrester inthe communication path of PROFBUS-PA so thatthe electromagnetic flowmeter will not be affectedby lightning etc.(6) The electromagnetic flowmeter is not equippedwith terminating resistors. Use the terminatingresistor unit for PROFIBUS-PA or junction box, ifnecessary.(7) Only one PROFIBUS-PA cable goes through acable gland of the Electromagnetic Flowmeter.Please use the junction box at systemconfiguration.(8) Install a terminator to flowmeter that connectedto end of Modbus network.300200100351030503 5 10 20 30 50 100 200Conductivity (μS/cm)Allowable cable length (m)Figure 12. Electrical Conductivity andCable Length Meter SizeTo select the meter size:See Table 3 to 4 and find meter sizes within thevelocity of 0.3 to 32.8 ft/s (0.1 to 10m/s) for aspecified full-scale (measuring range high limit)flow. Select one that has its full-scale velocitybetween 3.0 and 10 ft/s (1 and 3m/s).Note: Make sure the full-scale flow rate used for thefinal planning stage stays within 32.8 ft/s(10m/s) in terms of flow velocity.Table 3. Flow rate and flow velocity (English unit)Unit: gal/minSize(inch)Flow rate0.328 ft/s 0.98 ft/s 3.0 ft/s 10 ft/s 32.8 ft/s1/2 0.2801 0.8403 2.561 8.532 28.011 0.7781 2.334 7.115 23.72 77.811 ½ 1.992 5.975 18.21 60.71 199.22 3.112 9.337 28.46 94.86 311.23 7.967 23.90 72.85 242.8 796.74 12.45 37.35 113.8 379.4 1,245Table 4. Flow rate and flow velocity (SI unit)Unit: m3/hSize(mm)Flow rate0.1 m/s 0.3 m/s 1.0 m/s 3.0 m/s 10 m/s15 0.06362 0.1908 0.6361 1.908 6.36125 0.1767 0.5301 1.767 5.301 17.6740 0.4523 1.357 4.523 13.57 45.2350 0.7067 2.120 7.067 21.20 70.6780 1.809 5.428 18.09 54.28 180.9100 2.827 8.482 28.27 84.82 282.7

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