3.0 Operation; Operating Modes; Invert Mode; Transfer Mode - Magnum Energy MM Series Installation And Operation Manual

3.0 Operation

3.0 Operation

Operating Modes

The MM Series inverter has two normal modes of operation; 1. Invert
Mode, which powers your loads using the batteries, and 2. Transfer
Mode, which powers your loads from the incoming AC Power (i.e. utility
power or a generator). This inverter also has extensive protection
circuitry and will go into the Protection Mode under certain fault condi-
tions.

Invert Mode

In Invert Mode, the
inverting the DC power from the battery.
inverter can provide power is directly related to the capacity of the
battery (or battery bank).

Transfer Mode

The inverter will automatically go into the Transfer Mode whenever an
external AC source is connected and allowed to pass-thru to power your
AC loads. While in the Transfer mode, the AC input is continually
monitored to ensure it remains between 80 VAC (determined by the 'Adj
VAC dropout' setting) and 140 VAC. The status LED indicator will be on
(Transfer Mode) or blink off every four seconds (battery charging) to
indicate that the inverter is passing the input AC power to the output
and monitoring the AC input. Whenever AC power is disconnected or
falls below the 80 VAC threshold, the inverter automatically transfers
back to the Invert Mode with minimum interruption to your appliances -
as long as the inverter is enabled (turned on).
Transfer time - When the AC power falls below the VAC dropout
threshold voltage (80 VAC, default setting), the relay transfers from
Transfer Mode to the Invert Mode in about 16 milliseconds. While the
MM Series is not designed as a computer UPS system, this transfer
time is usually fast enough to hold them up. However, the VAC
dropout setting has an effect on the ability of the loads to transfer
without resetting. The lower this setting, the longer the effective
transfer will be and therefore, the higher the probability for the output
loads to reset. This occurs because the incoming AC voltage is allowed
to fall to a level that is so low, that when the transfer does occur (in
addition to the relay transfer time), the voltage from the inverters
output has already fallen to a low enough level to reset the loads.
The disadvantage of a higher VAC dropout setting is that smaller
generators (or large generators with an unstable output) may nuisance
transfer. This commonly happens when powering loads that are larger
than the generator can handle - causing the generators output to
constantly fall below the inverters VAC dropout threshold.
When switching from Invert Mode to the Transfer Mode, the inverter
waits approximately 15 seconds to ensure the grid is stable (or the
generator is up to speed) and then makes the transfer in approximately
8 milliseconds.
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inverter supplies AC power to your appliances by
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The amount of time
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the