Wiring - Toshiba LQ300A00 Series Operation Manual

3.5 Wiring

Figure 3.5.1 on the next page shows connections to the density meter and the external units. Figure 3.5.2
shows wiring assignment to a converter terminal. Refer to these figures for correct wiring.
[IMPORTANT]
(1) Provide a switch and a fuse to separate this unit from the mains power for ease of maintenance.
Power requirement of this unit is 50VA.
(2) Ground the LQ300A00****** with 100 Ohms or less ground resistance. Do not use a common ground
shared by other power equipment. The demands of the meter are 50VAs.
(3) Use a sheathed cable (CVV) with 2mm
voltage drop across the cable is less than 2 V. And use a M4 sized solderless contact for connection
cable with terminal.
(4) The cables should be free from vibration or sway. The cables should be placed in thick-walled steel
conduits.
(5) Wire the LQ300A00****** output in conduit separated from those of AC power cable, control signals,
alarm signal or other cables which could become the source of noise.
(6) Use a 2-wire shielded sheathed cable (CVVS) to wire the LQ300A00****** output (4 - 20mAdc). And
ground the shielded cable on the receiving instrument side. For performing the conductivity
compensation, use a 2-wire shielded sheathed cable (CVVS) to wire the LQ300A00****** conductivity
signal input (4-20mA). And ground the shielded cable on the receiving instrument side.
(7) As the cable port is made air-tight using a packing, tighten the cable gland securely when all the
wiring is completed. If the diameter of the cable is smaller than the inside diameter of the packing,
enlarge the cable diameter to the same size as the packing by wrapping valves around the cable. Its
suitable diameter is 11mm.
(8) Tighten the terminal screws securely. Appropriated torque to tighten the screws is 1.2 N･m .
(9) Do not turn on the power of the density meter when the applicators (antenna) are taken out of the
piping system. Leakage of radio waves may cause interference to external equipment.
cross-sectional area for AC power cable and make sure the
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