Festo IFB05-03 Manual page 137

A. Technical appendix
Festo P.BE−VIFB5−03−EN en 0503e
Formula for cable length:
− 21.6 V) · A ·
(V
Bmin
v
L
2
I


This means:
21.6 V V
VALVE TERMINAL
V = minimum supply voltage
Bmin
(at the power unit)
l = current for electronics and inputs
1
I = current for outputs/valves
2
A = cable cross−sectional area (uniform e. g. 1.5 mm
κ = conductance value of cables
κ
(uniform e. g.
Cu
Example:
I = 1 A
1
I = 5 A
2
V = 24 V
Bmin
V = 21.6 V
VALVE TERMINALmin
κ
= 56
Cu
Result of example:
L v 18 m for A = 1.5 mm
L v 30 m for A = 2.5 mm
κ
CU
+ I
2 1
= 24 V ± 10%, minimum: w 21.6 V
m
= 56
2
· Ω
mm
m
2
mm · ≅ Ω
2
2
2
)
A−11