Toshiba LF434 /LF620 Manual

TIC-LF434H9Wiring Precautions(1) Explosion proof type flowmeters are not providedwith cable 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 8.(4) DO1, DO2, and DI use the same common terminal(COM). This COM can not connect to otherequipment which have their own ground terminal.(Power supply for connecting to DI or DO, etc.)Need to wire separately. Wiring Precautions (PROFIBUS orModbus )(1) For wiring path, avoid places near electricalequipment that may cause electromagnetic inductionor electrostatic induction interference (such as amotor, transformer and wireless transmitter).(2) Use a PROFIBUS-PA cable for signal cable or aRS485 twisted-pair cable.In addition, 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 to humidity,rain, etc. When you install cables, make sure tocheck the operating conditions such as the operatingtemperature range of the cable by contacting itsmanufacturer.(4)When you carry out cable end treatment ofPROFIBUS-PA cable, use a dedicated cable stripperto avoid the core wire of the cable being nicked ordamaged. In addition, for cables, be careful ofallowable maximum bend diameter. (Do not allowexcessive twisting or bending of cables).(5)Consider installing a PROFIBUS-PA arrester in thecommunication path of PROFBUS-PA so that theelectromagnetic flowmeter will not be affected bylightning, etc.(6) The electromagnetic flowmeter is not equipped withterminating resistors. Use the terminating resistorunit 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 connectsto end of Modbus network.300200100351030503 5 10 20 30 50 100 200Conductivity (μS/cm)Allowable cable length (m)20Figure 8. Electrical Conductivity andCable Length Meter SizeTo select the meter size:See Table 3 to 4 and find meter sizes within the velocityof 0.3 to 32.8 ft/s (0.1 to 10m/s) for a specified full-scale(measuring range high limit) flow. Select one that hasits full-scale velocity between 3.0 and 10 ft/s (1 and3m/s).Note: Make sure the full-scale flow rate used for the finalplanning stage stays within 32.8ft/s (10m/s) in terms offlow 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 1,2456 28.01 84.03 256.1 853.8 2,8018 49.80 149.4 455.3 1,518 4,98010 77.81 233.4 711.5 2,372 7,78112 112.0 336.1 1,025 3,415 11,20014 152.5 457.5 1,394 4,648 15,25016 199.2 597.5 1,821 6,071 19,92018 252.1 756.3 2,305 7,684 25,21020 311.2 933.7 2,846 9,486 31,12024 448.2 1344.0 4,098 1,3660 44,820

/ 12

Related manuals for Toshiba LF430/LF620