Lower The Mast - Will Burt 7-30 HDL Operating Instructions Manual

6.3.3

Lower the Mast

To lower the mast:
1. Ensure the payload will have enough clearance when nested.
2. Close the drain cock.
3. If guy lines are used, decrease the tension on the guy lines until there is slack in the lines.
Never attempt to unlock a mast collar with tension on the guy lines above it. When
decreasing tension on the guy lines, begin at two locations opposite of each other and
gradually decrease tension on each guy line while observing to ensure the mast is not
bending too far towards one side.
Note: Do not leave mast system that requires guy lines unguyed. If the mast system has not
been lowered and personnel will not be available to operate the guy lines, re-guy the mast.
4. If operating the mast from the control box, select "BOX" on the control box. The "BOX/
REMOTE" switch is a maintained switch and will keep its position.
If operating the mast from the HHRC, select "REMOTE" switch on the control box.
If operating manually (typically an emergency operation when power is not available):
a. Ensure all electrical circuits are de-energized and properly tagged to prevent injury during
operation.
b. Disconnect the air hose at the base of the mast.
c. Connect a hand pump to the base of the base.
d. Use the hand pump to pressurize the mast until movement is seen in the first intermediate
tube. This is to lift the weight of the mast off the latching pins in the locks.
e. Manually actuate the latch pins using a screwdriver. The latch pins should move freely with
proper pressure. If the latch pins do not easily move, do not force them to actuate.
Pressurize the mast until the latch pins can be easily moved.
Note: Do not over-pressurize the mast as this will cause the locks to jam. In this instance,
release pressure until the latch pins can be easily moved.
f. With the latch pins actuated, continue to depressurize the mast. Once the first intermediate
tube begins to descend, the latch pins can be released. Continue to depressurize the mast
until it is fully retracted.
g. Skip to Step 9.
5. Select "HOLD". The "HOLD/EXHAUST" switch is a maintained switch and will keep its
position.
TP-5580101-A
FEBRUARY 2022
PNEUMATIC MAST WITH REMOTE LOCKING SYSTEM
OPERATING INSTRUCTIONS
PAGE 135 OF 164