Puls UB10.241 UPS Guide De Spécification

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UB10.241 
 
  USeries 
24V, 10A, DC-UPS 
 
 
 
Example how to determine the expected buffer time for other battery types and battery sizes: 
Step 1  
Check the datasheet of the battery which is planned to be used and look for the discharging curve. 
Sometimes, the individual discharging curves are marked with relative C-factors instead of current 
values. This can easily be converted. The C-factor needs to be multiplied with the nominal battery 
capacity to get the current value. E.g.: 0.6C on a 17Ah battery means 10.2A. 
 
Fig. 9-2   Typical discharging curve of a typical 17Ah battery, curve taken from a 
manufacturer’s datasheet 
 
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Step 2  
Determine the required battery current. Use Fig. 8-1 “Battery discharging current  vs. output current” to 
get the battery current. Fig. 8-1 requires the average voltage on the battery terminals. Since there is a 
voltage drop between the battery terminals and the battery input of the DC-UPS, it is recommended to 
use the curve A or B for output currents > 3A or when long battery cables are used. For all other 
situations, use curve C. 
Step 3 
Use the determined current from Step 2 to find the appropriate curve in Fig. 9-2. The buffer time 
(Discharging Time) can be found where this curve meets the dotted line. This is the point where the DC-
UPS stops buffering due to the under-voltage lockout. 
Step 4 
Depending on Fig. 9-2, the buffer time needs to be reduced to take aging effects or guaranteed values 
into account. 
Example: 
The buffer current: is 7.5A and a battery according Fig. 9-2 is used. The cable between the battery and the DC-UPS is 
1m and has a cross section of 2.5mm
2
. How much is the maximum achievable buffer time. 
Answer: 
ƒ 
According to Fig. 8-1, the battery current is 18A. Curve A is used since the battery current is > 3A and the 
length of the cable is one meter. 
ƒ 
According to Fig. 9-2, a buffer time (Discharging Time) of 30 Minutes can be determined. It is recommended 
to reduce this figure to approximately 24 minutes for a guaranteed value and to cover aging effects. 
 
June. 2010 / Rev. 1.3  DS-UB10.241-EN 
All parameters are specified at an input voltage of 24V, 10A output load, 25°C ambient and after a 5 minutes run-in time  
unless otherwise noted. It is assumed that the input power source can deliver a sufficient output current. 
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