Siemens OpenAir GEB 1 Series Technical Basics page 22

Line length/consumption
AC 24 V
L [m]
300
200
100
0
0
Notes on diagram
P&I diagram:
Voltage drop on the supply
lines
Formula for line length
22/44
Siemens
Building Technologies
The diagram applies to AC 24 V and shows the permissible line length L as a function
of consumption P and as a parameter of the line cross sections.
0.75 mm² 1 mm²
0.5 mm²
8
∂
The values in [VA, W] on the P-axis are allocated to the permissible voltage drops
Χ
( U/2U = 4 %) on line L as per the above table and to the P&I diagram.
∂
P is the primary power consumption for all actuators connected in parallel.
ΧU/2
R
L
U
R
L
Χ U/2
The maximum line length can be calculated using the following formula.
Operating voltage
AC 24 V
AC 230 V
A Line cross section in [mm
L Permissible line length in [m]
P Power consumption in [VA] or [W];
The value is printed on the actuator's type plate.
DC current portion in line G0 in ΖA∴
I(DC)
Actuators without spring return GEB...1
2.5 mm²
1.5 mm²
16
L
U,ΧU
M
L
Perm. voltage
Formula for line length
drop / line
1313 ∂
L =
4 % of AC 24 V
L =
1 % of DC 10 V
2 % of AC 230 V L =
46
2
]
24 32
A
Ζ ∴
m
P
5.47 ∂
A
Ζ ∴
m
I (DC)
1313 ∂
A
∂ Ζ ∴
m
P
P
[VA, W]
CM2Z4621en
2017-05-26