Hitachi ZAXIS 30U-5N Operator's Manual page 65

 If approximately 3 hours has passed without previous
regeneration being completed, the muffler filter
regeneration request will flash, the buzzer will sound,
and the engine speed and power will drop. (refer to 1-26)
Perform manual regeneration following the specified
procedure in this case. (refer to 1-27)
 When the machine is operated without performing
manual regeneration, the muffler filter may be damaged.
Immediately move the machine to a safe area and perform
manual regeneration.
 If the machine is continuously operated without
performing manual regeneration, the engine speed
and power will drop. The engine will automatically stop
approximately after 2 hours. If the muffler filter alarm or
engine trouble alarm is displayed, the buzzer will sound
and the engine will automatically stop approximately after
30 minutes. At this time, consult your authorized Hitachi
dealer for repairing the muffler filter.
 Both auto and manual regenerations restore muffler filter
function. It is not a malfunction.
 If auto-regeneration interval becomes shorter, consult your
authorized Hitachi dealer.
 White smoke may occur for several minutes after the
engine start, this is not a malfunction.
OPERATOR'S STATION
1-5