The control valve lever must never be held or
left in any position between 1 and 2 or 2 and 3,
since this allows fluid to drain from the
accumulator, through the system, to the gravity
The power package accumulator does not contain
sufficient fluid to raise and lower the stanchions more
than three times without the pump operating.
Approximately 20 minutes is required for the pump to
replenish fluid to the operating level in the accumulator,
if stanchions are cycled three times without the pump
operating. The READY CONDITION for normal
operation specifies 1,500 psi accumulator pressure;
however, stanchions will raise and lower, taking a
longer period of time with a lower pressure, as is
experienced if stanchions are cycled without the pump
operating. Pressure at the start of the third cycle will be
approximately 850 psi without the pump operating.
If the stanchions are cycled more than three times
without the pump operating, air will enter the piping
and cylinders, and fluid will overflow the gravity tank.
It is then necessary to fill, vent, and charge the system
as specified in the applicable operating manual.
During the READY and SECURE conditions, the
following checks are to be made:
Figure 3-46.Barricade stanchion controls.