Power Supply - Bartec BAT VGA pro Manuel D'installation

Operator´s manual for BAT VGA pro
Version 1.1
3.5.2

Power supply

A stabilised power supply unit delivering at least 2 A must be used. The voltage supply at the point of installation must
not be outside the voltage tolerance of DC 24V + 10%. Account must be taken of voltage drop in the supply line and, if
necessary, appropriate corrective measures must be taken.
Line voltage drop is calculated in accordance with the following formulae:
∆U
Line voltage drop at power supply unit
voltage 24V DC
∆U
Line voltage drop at maximum permissible power
supply unit over voltage 24V DC +10% (26,4V))
I Current for one display terminal
Conductor cross-section of supply cable
A
κ
Specific conductivity of copper
Length of the power cable (supply and return)
l
l
=
R
κ
⋅
A
Examples
Supply voltage 24 V DC
If the voltage drop cannot be compensated for or if the calculation gives a conductor cross-
section which is too large, a separate power supply unit must be installed close to the point of
installation.
Example:
Connecting the power supply to the display terminal connects the earth of the power
supply cable with PE! If the power supply cable earth is not electrically isolated, it must
be ensured that there is no difference in potential between it and PE/PA.
E_BMS00680_Rev7.doc • Operator´s manual for BAT VGA pro • Revision 7 / Status: 29. January 2004 • Technical data subject to change
∆
U
=
R
I
Conductor cross-section
Explosion protected housing or outside of the hazardous area on the
outer wall of the building.
max. 2.4 V
max. 4.8 V
(until 10% under voltage is reached)
min. 0.8 A
m
56
Ω ⋅
mm ²
l
∆U = ⋅
I
κ
⋅
A
Maximum cable length
0.75 mm²
1.5 mm²
2.5 mm²
Page 41
approx. 50 m
approx. 100 m
approx.. 170 m