Datafox Evo 4.3 - Calculation for the Power Supply of Access Modules

Manual Datafox Evo 4.3 Page 99 Date: 27.12.2017 V 04.03.09.XX
5.7.7. Calculation for the power supply of Access modules
When using Datafox access readers or door modules, the necessary cable cross-section has to be
calculated before setting up an RS485 network for access control. The voltage drop in the whole
bus must not exceed 4 V. Please note that if you use a Datafox device power supply unit as voltage
source, 16 modules at most (8 in the RS485 bus and 8 via RS232 stub line) can be fed.
Maximum power consumption of the single modules:
TS-TMR33-TR 56,5 mA 16 V max. 8 V min.DC
TS-TMR33-TM 156,0 mA 16 V max. 8 V min.DC
TS-TMR33-TMR 180,0 mA 16 V max. 8 V min.DC
EVO-ZK-Leser 250,0 mA 24 V max. 9 V min.DC
PHG-ZK-Leser 250,0 mA 24 V max. 9 V min.DC
The result is a permissible maximum power consumption per Datafox power supply unit of (8 x
180.0 mA + 8 x 56.5 mA) 1.9 A. In order to assure this, you can calculate the necessary cross-
section for a given cable length or the permissible maximum cable length for a given cable cross-
section.
!
Caution:
Before setting up and commissioning a ZK-network, the calculation
has to be done by a person qualified in this field.
The cable cross-section is calculated as follows:
vUk
lI
Q



2
Für 12 V Spannungsversorgung gilt:
Uv = voltage drop. 4V at most. 4 V TMR33
Uv = voltage drop. 4V at most. 3 V PHG and Reder EVO-ZK
Uv errechnet sich aus Versorgungsspannung minus Mindestspannung für den Leser.
Thus, the equation for calculating the maximum cable length for a given cable cross-section
is:
I
UkQ
l
v



2
Q = Leitungsquerschnitt in mm
2
I = Stromstärke
l = Leitungslänge in m
k = Leitfähigkeit für Kupfer 56
2
mm
m
