Minuteman UPS CPE 1000 ユーザーズマニュアル

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Chapter Four: The Working Principle of the UPS 
 
4.1. When Utility is Normal 
 
The working principle of the UPS under normal Utility conditions is illustrated 
as follows: 
 
 
 
When Utility is normal, the AC source is rectified to DC, partially fed into the 
charger to charge the battery and partially fed into inverter.  The inverter 
reverts the DC to AC to supply energy to the output load.    The Utility LED 
and Inverter LED will illuminate. 
 
 
4.2. When Utility is Abnormal 
 
The working principle of the UPS under abnormal Utility conditions is 
illustrated as follows: 
 
 
 
When Utility is abnormal, the UPS will direct the battery energy to the 
Inverter.    The charger and AC/DC converter will turn off.    The inverter will 
revert the DC to AC to supply power to the output load.    The Inverter LED 
will illuminate. 
  O/P
OUTPUT
---  4-1 ---
RECTIFIER
  O/P
OUTPUT
---  4-2 ---
 
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When the Utility power returns to normal, the AC/DC converter and the 
charger will turn on.  The DC/DC converter will turn off.  It has the same 
working principle as figure 4.1. 
 
During a blackout, the UPS will work as illustrated in figure 4.2.    When the 
battery is low, the alarm will beep continuously until the battery is depleted 
and the UPS shuts down.  The Low Battery Cut-Off protection turns the 
UPS off to prevent discharging batteries to an unsafe level.  The Inverter 
LED and the Battery Low LED will be illuminated until the UPS shuts down.   
The UPS will Auto-Restart when the Utility power returns to normal.    This is 
the same working principle as figure 4.1. 
 
 
4.3. Overload Condition 
 
The working principle of the UPS when overloaded is illustrated as follows: 
 
 
 
Normally, an inrush current is generated when turning on the connected 
equipment. 
 
If the UPS is 105~120% loaded, it will switch to the Bypass mode in 60-
seconds. 
 
If the UPS is 120-150% loaded, it will switch to the Bypass mode in 10-
seconds. 
 
If the UPS is over 150% loaded, it will switch to the Bypass mode 
immediately. 
 
The Utility LED, the Bypass LED and the Overload LED will be illuminated.   
If overload condition is removed the UPS will switch back to the On-Line 
mode automatically. 
 
  O/P
OUTPUT
---  4-3 ---