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When the inverter is turned on, the output voltage gradually ramps up from 0VAC to rated voltage in about
1.2 sec. This effectively reduces otherwise very high starting inrush current drawn by AC loads such as
Switched Mode Power Supplies and inductive loads. This will result in lower motor inrush current, which
means less impact on the loads and inverter.
Caution:
After the inverter is switched on, it takes a finite amount of time to self-diagnose and get ready to deliver
full power. Always switch on the load(s) after a few seconds of switching on the inverter. Avoid switching
on the inverter with the load already switched on. This may prematurely trigger the overload protection.
When a load is switched on, it may require an initial higher power surge to start. If multiple loads are being
powered, they should be switched on individually so that the inverter is not overloaded by the higher starting
surge.
2.4.2 AC & MPPT Charger
The M Series pure sine wave inverter/charger is equipped with an active PFC (Power Factor Corrected)
multistage battery charger. The PFC feature controls the amount of power used to charge the batteries in
order to obtain a power factor as close as possible to 1.
Unlike other inverters whose max charging current decreases according to the input AC voltage, the M
Series pure sine wave inverter/charger is able to output maximum charging current as long as input AC
voltage is in the range of 154~260VAC, and AC frequency is in the range of 48-54Hz(58-64Hz for 60Hz
model).
The M Series pure sine wave inverter/charger has a very rapid charge current available, and the max charge
current can be adjusted from zero to 100% in small increments on the inverter’s LCD. This is helpful if this
powerful charger applies charging to a small capacity battery bank.
There are three main charging stages:
Bulk Charging:
This is the initial stage of charging. While Bulk Charging, the charger supplies the battery
with controlled constant current. The charger will remain in Bulk charge until the Absorption charge voltage
(determined by the Battery Type selection) is achieved.
A software timer will measure the time from charger start until the battery charger reaches 0.3V below the
boost voltage, then take this time as T0 and T0×10 = T1.
Absorb Charging:
This is the second charging stage and begins after the absorb voltage has been reached.
Absorb Charging provides the batteries with a constant voltage and reduces the DC charging current in order
to maintain the absorb voltage setting.
In this period, the inverter will start a T1 timer; and the charger will keep the boost voltage in Boost CV
mode until the T1 timer has expired. The voltage will then be reduced to the float voltage setting. The timer
has a minimum setting of 1 hour and a maximum setting of 12 hours. When charging current falls below
0.01C, the charger will switch to the float charge.
Float Charging:
The third charging stage occurs at the end of the Absorb Charging time. While Float
charging, the charge voltage is reduced to the float charge voltage (determined by the Battery Type
selection*). In this stage, the batteries are kept fully charged and ready if needed by the inverter.
If the battery type is selected as “lithium battery”, our charger will drastically reduce the charging current to
zero once float voltage is reached.
