JA-101K(-LAN)(-LAN3G) and JA-106K(-3G)
Security System Control Panels
22
/
110
MLJ51410
not exceed the maximum continuous consumption of current from the control panel, see chapter 5.8 Example
of calculation of BUS consumption to back-up the system. To calculate the total continuous consumption
of connected elements summarize their
backup consumption
(it is specified in the manual or use
the summarizing table, see 14.1 Overview table of current consumption of BUS devices.
Another limiting parameter for the max. length of a BUS can be the voltage loss along the line (shown clearly
by the System Diagnostics in F-Link).
5.6
Calculation of line losses
Voltage losses along the line depend on the line resistance, which results from the used conductor (cable) and
consumed current. Current consumption values of devices can be found in individual manuals. These values
can be used to calculate the line voltage loss and to find out whether there will be sufficient voltage available for
the last installed device. The calculation is based on Ohm’s law
U = I * R
CC-01 cable
(power supply pair)
CC-02 cable
CC-03 cable
(power supply pair)
total current
max. length
total current
max. length
total current
max. length
50 mA
400 m
25 mA
200 m
70 mA
400 m
100 mA
300 m
50 mA
150 m
140 mA
300 m
200 mA
150 m
100 mA
100 m
280 mA
150 m
300 mA
100 m
200 mA
50 m
420 mA
100 m
500 mA
50 m
300 mA
30 m
800 mA
50 m
The data in the table assume the worst possible case i.e. that the total consumption is at the end of the cable.
In the normal operation state the voltage of the +U and GND terminals is nearly 14 V. For the calculation
consider a situation when the control panel is only powered by the battery and the voltage approximates 12 V.
A higher voltage than the minimum allowed voltage of 10 V must be available for all the devices. For proper
functioning of the connected devices the
maximum allowed voltage loss is 2.0 V.
Unexpected voltage loss can be caused by terminal connections with a poor contact (transitional resistances).
Voltage losses of individual devices can be approximately verified using the F-Link software
in the Diagnostics card for addressed devices. Non-addressed devices (e.g. output modules) do not provide this
possibility; they must be checked with a measuring device.
In a real-life installation we always recommend you to verify the calculation and connection by terminal
measurement. In the case of high-consumption devices (siren, keypad, relay output) carry out this measurement
during increased consumption periods (active siren, backlit keypad, engaged relay).
The limitations specified in the table are generally valid.
For the calculation of the total load of cables calculate the
consumption for cable selection
(you will find
it in the manuals of devices or you can use the summarizing table in chapter 14.1 Overview table of current
consumption of BUS devices.
5.7
Example of a voltage loss calculation:
1. Find the values of current consumption of individual devices (in the technical parameters of the products
- current consumption for cable selection).
2. Get information about cable lengths. You need to know the cable length as exactly as possible from
node to node.
3. Draw a plan with cable lengths and consumption of individual branches.
4. Calculate the electric current flowing through individual branches.
5. Use the assumed line length and the estimated values of current of individual branches in accordance
with tab. 4 to compare suitability of cable selection.
Deduct individual losses from the supply voltage to determine the voltage at the line end. Always consider the
voltage of 12 V from the control panel during mains supply failure operation.