Operating instructions

7
Note: The locking collars are adjusted during assembly. However, if any locking
collar is not clamping the section securely when fully tightened, if should be released
and the socket screw or thumbscrews adjusted until the clamping action is sufficient.
As a guide the gap on each side of the locking collar should be equal when that
locking collar has been tightened. If one side is closed too much, the mast section
may not release properly.
For frequent operations or for situations where the sections will be locked more
permanently the thumbscrews can be replaced with socket set screws operated with
a T key.
NY series
NY series masts are built are built specifically for high accuracy/high load operation
and would normally form part of a fixed installation.
Standard NY series masts are not supplied with locking collars; therefore, loads
would normally be carried on a maintained column (see maximum air pressures in
Safety section). NY series of masts must be operated at full extension.
Locking collars can be fitted at extra cost. (Ask for details)
(1) When pressurising the mast, it is imperative to ensure the free running of all
antenna feeders and other equipment cables. The mast extension could be
powerful enough to snap the cable and the air pressure supplied to do this will
cause the mast to shoot up, possibly with sections crashing into their respective
collars, resulting in heavy shock loads.
(2) Air must be exhausted in a controlled manner. Remember that the NY series of
masts can carry a dead weight up to 120kg. All Hilomast compressors are fitted
with either manually or electrically operated exhaust valves. If a remotely
operated exhaust valve is fitted to the mast a restriction nozzle may be required
to give a maximum descent speed for the load the mast carries.