Calculation Of Voltage Drop Value; Rated Voltage - Panasonic S-LINK V User Manual

Calculation of Voltage Drop Value

The transmission cables of the S-LINK V system may cause voltage drop due to the conductor resistance of the
cables themselves. For this reason, calculate the voltage drop value between +24V and 0V, and supply the rat-
ed voltage to all the S-LINK V I/O units. However, it is not necessary to consider the voltage drop between the D
and G, and that of the control cables and connector link cables.
CAUTION
Use of a longer cable will cause more voltage drop. If the voltage drops below the rated voltage, the
I/O units will not work. In this case, use the local power supply unit.
Voltage drop (V) = Cable length (m) × 2 × conductor resistance (Ω/m) × current (A)
Relation between the ambient temperature and allowable passing current when exclusive S-LINK V
cable SL-RCM100□ / RCM200 or SL-CBM100 / CBM200 (conductor cross section = 0.5mm
cable) is used.
Rated voltage (V)
CAUTION
The rated voltage depends on the unit. Check the rated voltage, and then select the right power sup-
ply unit and cables.
Supply the rated voltage to each unit.
● Since the rated voltage to be supplied to the controller is +24V (-5%), the voltage supplied to the con-
troller should not be dropped below the following value:
24 - (24 × 0.05) = 22.8V
● Since the rated voltage to be supplied to the I/O units and end unit is +24V (-10%), the voltage sup-
plied to these units should not be dropped below the following value:
24 - (24 × 0.1) = 21.6V
Elongation of the transmission distance will cause more voltage drop
at the line end (between +24V and 0V).
8
7
6
5
4
0 5 10 15 20
Ambient temperature (˚C)
Power Supply Capacity of System
25 30 35 40 45 50
2
for each
55 60
23