User Instructions
www.pulsar.pl   EN54C    RED POWER plus 
18 
6. Reserve power supply circuit. 
  The  PSU is fitted with intelligent  circuits:  battery charging  circuit  with the function of  the accelerated 
charging and battery control, which main task is to monitor the condition of the batteries and the connections in 
the circuit. 
 If the controller detects a power failure in the battery circuit, appropriate indication and change of the 
ALARM technical output. 
6.1. Battery detection. 
The control unit of the PSU checks the voltage at the battery terminals and, depending on the measured 
values, determines the appropriate reaction: 
U
BAT
 below 4 V  - batteries not connected to the PSU circuits  
U
BAT
 = 4 to 20 V - faulty batteries 
U
BAT
 over 20 V   - batteries connected to the PSU circuits 
6.2.  Protection against short-circuit of the battery terminals. 
  The PSU is fitted with the circuit protecting against short-circuit of the battery terminals. In case of short 
circuit, control circuit immediately disconnects the batteries from the rest of the power supply circuit, so the loss 
of output voltage on power supply outputs is not observed. Automatic reconnection of the batteries to the PSU's 
circuits is only possible after the removal of the short-circuit and correct connection of the circuits. 
6.3.  Protection against reverse battery connection. 
The  PSU  is  protected  against  reverse  connection  of  the  battery  terminals.  In  case  of  incorrect 
connection, the F
BAT
 fuse in the battery circuit becomes blown.  The return to normal operation is possible only 
after replacing the fuse and correct connection of the batteries. 
6.4.  Deep discharge battery protection UVP. 
The PSU is fitted with the disconnection system and the battery discharge indication. If the voltage at  
the  battery  terminals  drops  below  20  V±0.2  V  during  battery-assisted  operation,  acoustic  indication  will  be 
activated and the batteries will be disconnected within 15s.  
The batteries are reconnected to the power supply unit automatically  once the 230 V mains supply is 
restored. 
6.5.  Battery test. 
The PSU runs battery test every 5 minutes. During testing, the control unit of the PSU measures the 
electrical parameters according to the implemented measuring method.  
A negative result occurs when the: 
- battery circuit continuity is interrupted,  
- resistance in the battery circuit increases above 300 mΩ 
- terminal voltage drops below 24 V. 
The battery test will also be automatically locked when the PSU is in the operating mode, in which the 
battery test is impossible. Such condition occurs, for example, during battery assisted operation. 
6.6.  Measurement of the resistance of the battery circuit. 
The PSU is checking the resistance in the battery circuit. During the measurement, the PSU driver takes 
into account the key parameters in the circuit,and once the limit value of 300m ohms is exceeded, a failure is 
indicated.  
A failure may indicate considerable wear or loose cables connecting the batteries. 
6.7.  Battery temperature measurement. 
Temperature  measurement and compensation of the battery charging voltage can extend the life of the 
batteries.  
The  PSU  has  a  temperature  sensor  to  monitor  the  temperature  parameters  of  installed  batteries.  It  is 
recommended  to place the  temperature sensor between  the  batteries.  Be  careful not to damage  the  sensor 
when moving the batteries. 










