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5. Installation
5.5. Installation Cable Length
[Table 7. GTD- 3000Ex Power Cable Installation Length]
AWG
mm
2
COPPER RESISTANCE(ohms/m)
METERS
12
3.31
0.00521
2879
14
2.08
0.00828
1811
16
1.31
0.01318
1138
18
0.82
0.02095
715
20
0.518
0.0333
450
[Figure 12. Calculation of GTD-3000Ex Installation Cable Length]
■ The maximum length between GTD-3000Ex and power supply is decided by wire specification.
■ Max. Installation Length = VMAXDROP ÷ IMAX ÷ WIRER/m ÷ 2
·
VMAXDROP: Maximum Power Loop Voltage Drop (=Power Supply voltage
- min operating voltage)
·
IMAX : Max. Current of GTD-3000Ex
·
WIRER/m: The resistance of the wire (ohms/meter value available in wire manufacturer's specification data sheet)
■ Example of installation lengths using 24 V power supply and 16 AWG is as follows.
·
GTD-3000Ex minimum operating voltage = 18 Vdc
·
VMAXDROP = 24 - 18 = 6V
·
IMAX = 0.2A ( 200mA )
·
6 ÷ 0.2 ÷ 0.01318 ÷ 2 = 1138.088m ≒ 1138m
■ Power cable installation for each cable type is as shown in the table below.
