CARLO GAVAZZI CAR PARK 3 OUTDOOR, Общее руководство по установке и эксплуатации

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Car Park 3 – General installation 29
5.3 How to calculate the cable length
If you are searching for different installation methods, please follow the calculation examples
below:

Conductor resistance for 1.5 mm
2
(or AWG16) cross-section wire: 13÷15 Ω /km
This value varies depending on the temperature by a few percent based on purity and process
of manufacture. Please refer to conductor manufacturer datasheet.
The link provided below is an example:
https://www.sab-cable.com/cables-wires-harnessing-temperature-measurement/technical-
data/cables-and-wires/american-cable-stranding.html

Current consumption by each sensor: 28 mA
Note: The SBP2MCG324 generator has a maximum output current of 2.6 A.

The Voltage drop must be maximum of 3.5V from the cabinet to the last sensor on the line.
The voltage drop can be calculated basing on the Ohm’s law V = R *I. The calculation formula the
following:
Conductor resistance =
R
C
Current consumption by each sensor = I
s
Note: * Multiplied by 2 because it is a one run (2 wires: D- and POW)
Total voltage drop from C MCG to end of the line = ∑ (∆V1+ ∆V2+….+∆Vn
th
)
This formula can be used to calculate the above-mentioned unknown factors in a car park line. See
the CP3 - Voltage drop calculation spreadsheet.
Please contact your Carlo Gavazzi Sales office if you have any questions regarding the
calculations, or if you need help with your calculations.
Voltage drop between CMCG and
1 st sensor (1
st
segment)
∆ V1 = 2 * ( R
C
* cable length from CMCG to 1
st
sensor) * (Total
sensors in line * I
s
)
Voltage drop between 1
st
sensor
and 2
nd sensor (2 nd segment)
∆ V2 = 2 * ( R
C
* cable length between 1
st
and 2
nd
sensor) * [(Total
sensor - Sensors between 1
st to 2 nd segment) *
I
s
)
…….. ………
Voltage drop between
(n-1)
th and
n th sensor (last segment)
∆ Vn
th
= 2 * (
R
C
* cable length between (n-1)
th
and n
th
sensor) * [(Total
sensor - Sensors between 1
st
to last segment ) * I
s
]