SK400T48  SK400T60

for parallel revitalization
of battery set

RECTIFIERS  I1400T48 and I1400T60 v4

   Rectifiers I1400T48 (60) v4 are designed in switchmode technology primarily  for power supply of telephone exchanges, together with system S3000, but  can be used as entirely independent units for power supply of other devices  with identical power specifications. Rectifier systems are supplied power from  three-phase or mono-phase sources or AC current (power grid or generator),  each rectifier unit is supplied in mono-phase. Output voltage is strictly  regulated in the whole range of permissible variations of the mains network  and load. In power supply systems such as S3000 the rectifiers are connected  in parallel, and the division of current among modules is performed  automatically.
   Rectifiers can operate fully even without accumulator batteries in telephone  exchanges of lower capacity. In systems with uninterrupted power supply, the  rectifiers are also used for maintenance of accumulator batteries 48V, 60V of  differing capacities. When doing that, a separate device is used for  diagnosing the state of the batteries and switching on the appropriate mode  of charging  (charging or floating).
   The main function of rectifier is the conversion of energy, in particular the  conversion of effective AC voltage of 230Veff into DC voltage of 48V (60V).  The energy conversion is done by the power processor, dimensioned to  provide up to 1400W of output power. Power processor is designed in  switching technology, where transistor is the main switching element, and the  working frequency is  50kHz. The rectifier is homologated by the Community  of Yugoslav PTTs.


Input data

Mains voltage (Vu) 220/230Veff
Permissible mains variation -15% to +10%
Mains frequency 47 to 63Hz
Permissible fluctuation -15% to +10%
Permissible distortion 30%
Input current for nominal load 7A
Input current during switch-on < 15A
Input fuse 10A, fast
Power factor ( cos j )   > 0.99
Protection   overvoltage, undervoltage, fuse
Output data for I1400T48
Nominal output voltage 48V
Floating voltage adjustable 49-56V temperaturally controlled 0°C to 35°C
Recharging voltage adjustable 52-58V temperaturally controlled 0°C to 35°C
Voltage stability better than 1%
Nominal current 25A
Current limitation 26A
Output power 1400W
Power density 135W/dm3
Response time   1ms
Psophometric noise < 1mV
Noise voltage < 20mVeff, 100mVpp
Protection overvoltage, undervoltage, overcurrent, short circuit
Output voltage for I1400T60
Nominal output voltage 60V
Floating voltage adjustable 61-69V
Recharging voltage adjustable 65-73V
Stability better than 1%
Nominal current 20A
Current limitation 21A
Output power 1400W
Power density 135W/dm3
Response time 1ms
Psophometric noise < 1mV
Noise voltage from  10Hz to 450kHz < 20mVeff
Protection overvoltage, undervoltage, overcurrent, short circuit
General data
Working frequency 50kHz
Efficiency > 0.9
EMI (RSO) JUS N.No-900
Working temperature 0°C to +40°C
Permissible humidity to 80%
Storage temperature -10°C to +75°C
Instrument display digital, 1%
Mounting modular "plug-in"
Parallel work directly connecting the outputs
Management and control microcontroller
Communication serial, RS485
Temperatural protection 70°C
Height 250mm
Width 130mm
Depth 390mm
Weight 8.5kg
Mean time between failures  40 years
Spare parts and service 20 years
Warranty 3 years
Homologated by Community of Yugoslav PTTs  


    Serial converters, series SK400T... are manufactured in two versions,  differing in output characteristics: 0-8V/50A, 0-11V/37.5A. They are designed in  switchmode technology and are used primarily with the telephone exchange  power supply system S3000 and other telecommunications equipment, but can  also be used as a completely independent power supply units for equipment  requiring said voltages, whose power is not greater than 400W. Serial  converter is powered from DC current source (most frequently batteries). The  output voltage (sum of input and output voltage) is strictly regulated in the  whole range of permissible variations of supply and load. To enhance the  output current and reliability, it is possible to make a parallel connection of  several serial converters, where the current division among separate modules  can be finely tuned.
    While working in parallel, the converters are used for stabilization of  distribution voltage (output system voltage) in cases of power blackouts and  switching over to standby battery supply. During voltage downgrading the  serial  converters are switched on and they "supplement" battery voltage, so  the distribution voltage (on the consumer) is constant. In this way, the system  autonomy is sustained, considering that the distribution voltage is constant,  not depending on the variations of the input voltage or load.
   Serial converter has nominal DC voltage of 0-8V (0-11V) on the output when  it has DC voltage of 48V (60V) on the input. Whence the negative end of input  voltage is connected to the positive end of output voltage. The power  processor converts the input voltage into the output voltage of the serial  converter. The power processor is done in switchmode technology with  MOSFET transistor as the main switching element. The working frequency is  40kHz. The converter had been homologated by the Community of Yugoslav  PTT.


Input data for SK400T48

Input voltage 48V
Permissible range of input voltage 37.8-56V
Current during switch-on 10A
Input fuse automatic 15A
Protection overvoltage, undervoltage, overcurrent
Output data for SK400T48
Output voltage 0-8V
Nominal distribution voltage 49V
Distribution voltage adjustable 45-54V
Stability better than 1%
Nominal current 50A
Current limitation 55A
Output power 400W
Response time 1ms
Ripple < 50mVp-p
Voltage surge amplitude < 2Vp-p
Protection overvoltage, undervoltage, overcurrent
Input data for SK400T60  
Input voltage 60V
Permissible distortion 47.2-70V
Current during switch-on 10A
Input fuse automatic 15A
Protection overvoltage, undervoltage, fuse
Output data for SK400T60  
Output voltage 0-11V
Nominal distribution voltage 65V
Distribution voltage adjustable 59-70V
Stability better than 1%
Nominal current 36,4A
Current limitation 40A
Output power 400W
Response time 1ms
Ripple < 50mVp-p
Voltage surge amplitude < 2Vp-p
Protection overvoltage, undervoltage, overcurrent

General data

Operating frequency 50kHz
Efficiency > 0.75
System efficiency > 0.97
Permissible ambient temperature 0°C to +45°C
Permissible storage temperature -10°C to +70°C
Permissible humidity up to 75%
Temperatural protection 85°C
Indicating instruments digital, 1%
Outer dimensions
Height 258mm
Width 90mm
Depth 395mm
Weight 4,8kg
Mean time between failures 40 years
Spare parts and service 20 years
Warranty 3 years
Temperatural protection 85°C

for parallel revitalization of a battery set

    B3000 is a microprocessor controlled system for simultaneous independent  revitalization of individual cells from the set. The system consists of DP0380  charger and DISI4815 discharger and it provides automatic cycling of batteries,  performed independently for each of the cells and defined by the user. The  system can be connected to a PC during or after revitalization, providing  direct monitoring of the state of accumulator batteries. It is also possible to  connect an extra external recharging set, to raise the system current from 80 to  200A per cell. During revitalization the user defines all the parameters for each  individual cell and the whole set. The charger has cables for each individual  cell and sense wires for measuring the voltage.


    After switch-on, the user sets parameters of the device, depending on the  battery set in question. Thus, discharging of each cell is controlled, and when  the voltage on it drops below the minimal permissible voltage, the discharging  is stopped, the cell current is set to zero, and it waits for all cells to be in the  same state. After that recharging is started. The operation of device in this  state is defined by the limited recharging current and optimal compensation  temperature. The cells switch from the state of constant current to the state of  constant voltage, and they remain so until the cell current drops below the  defined threshold or the time set for charging is up. The user can then choose  to enter extra mode, where the battery is charged with overvoltage for a short  period of time. This concludes the first cycle of revitalization.
    The duration of the electrolytes forming mode is defined by the user.  Overall, three cycles are propounded, after them it can be diagnosed which of  the cells and to what extent had been revitalized. Parameters that are  measured are transient voltage, transient current, capacity of each individual  cell and battery set temperature. After each cycling the change in each cell's  capacity is measured. The results can be displayed on LCD or presented on a  PC with the graphic comparative analysis of each cell's capacity for all of the  three cycles performed. A similar diagram is presented for the voltages and  currents of each cell.
    The system is autonomous and after switch-on, no intervention from user is  necessary until the completition of all three cycles (or less, depending on the  values set in the user menu). All the parameters are adjustable in software,  including temperature gradients for different battery types. The device can  revitalize sulphatized batteries or batteries with capacities reduced to 30-50%  of the nominal/transient capacity.