Njoy Alvis Series User Manual page 11

When input mains power returns to normal range, the
AVR will restore the output automatically.
6.3
Under Voltage (Low Voltage) Protection
In case that input voltage is below the normal range, the
output will be cut off automatically and a letter "L" will be
shown in the display.
When input mains power returns to normal range, the AVR
will restore the output automatically.
6.4
Over Temperature Protection
In case that the temperature of transformer windings
is beyond the normal range, the output will be cut off
automatically and letter "c" will be flashing in the display.
When temperature of transformer windings returns
to normal range, the AVR will restore the output
automatically.
6.5
Short Circuit Protection
In case a short circuit happens to the AVR or appliances,
the AIR BREAKER or CIRCUIT BREAKER will trip off to cut
off the input power supply.
Check if the appliances have been short circuited, if so,
please remove them.
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