AEC IST7 20kVA, User Manual

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2 Overview
AEC UPS IST7 10-30 KVA
User Manual
10
Normal mains mode
When the mains normal, AC power is transformed to DC power by PFC, and supply power for inverter.
While rectifying the AC power into DC power, the rectifier eliminates the abnormal noise wave, noise
and unstable frequency, and make the inverter provide stable and clean power for load. The specific
work process is as follows.
When mains normal, the rectifier, inside the power unit, rectify the mains into anode and cathode DC
voltage, and store energy in DC electrolysis for inverter to use. The inverter absorbs energy from DC
electrolysis and inverts to output stable 220Vac voltage. When the system control card detects the
inverter normal, it will supply the inverting voltage to load.
Battery mode
When mains abnormal, system will switch to battery input, the Boost circuit promotes the battery
voltage to a certain value and then supply the DC power to the inverter, that makes the AC output
without interruption phenomenon and then protect the load. The specific work process is as follows.
When mains abnormal at any time, the rectifier will switch to battery input immediately to maintain
the voltage of DC electrolysis, which guarantee the inverter without power down. Before battery
discharge completely, if mains recovers, the rectifier will switch to mains input and charge battery at
the same time. During the switch between grid power supply and battery power supply, the inverter
output cannot power down.
In battery power supply mode, if mains does not recover normal all the time, and the battery energy is
running out, the UPS will send sound & light alarm, and stop working at the max. discharge point, and
long beeps to alarm. At that time, the load will power down.
Bypass mode
When system abnormal (such as over-temperature, short-circuit, output voltage abnormal or overload)
and exceed the bear range, the inverter will shut down to avoid damage automatically. If mains still
normal at this time, it will turn to bypass to supply power for load. The specific work process is as
follows.
If the inverter circuit fault or inverter overload and exceed the bear range, the UPS will turn to bypass
to output. During bypass power supply, if fault or overload removed, the UPS will start inverter and
begin to supply power for load. When the load is serious overload and exceeds the bypass bear range,
the UPS will close the bypass output, and it will cause user load power down. When load fault or short
circuit, the UPS will switch to bypass to supply power from inverter. If the short-circuit is serious, the
UPS input breaker and bypass breaker may trip out. After suffering the short-circuit fault, UPS will try