Operating instructions
6
OPERATING INSTRUCTIONS
NH/NK/NL/NX Series Hilomasts
(1) Close the mast exhaust valve by turning in a clockwise direction until finger tight.
(2) All locking collars, with the exception of the top one, should be securely tightened
by turning the thumbscrew in a clockwise direction. The locking collars are
situated immediately above the guide collars at the top of each section.
(3) Connect the air supply to the mast (see maximum air pressures in safety
section). When the top section is fully extended the locking collar should be
securely clamped with thumbscrew. It is sometimes helpful to switch off the
compressor between clamping sections. The next lower collar should then be
released and that section raised and clamped and so on, until the mast is fully
extended.
(4) If the mast is to be used for frequent operations of short duration, the collars need
not be clamped, since all Hilomast compressors are fitted with differential
pressure switches that will maintain mast air pressure.
(5) To lower the mast, open the mast exhaust valve by turning anti-clockwise. When
the air is released, unclamp the lowest collar. As each section of the mast
descends it will bring down the next collar for release and so on, until the mast is
fully retracted. The rate of decent cannot be increased as it is controlled by the air
release valve to protect the mast.
(6) In the case of NX series masts carrying large headloads, additional control over
the rate of descent may be afforded as follows:
After releasing air pressure (see 5), close the mast exhaust valve before releasing
the locking collars. The load will then be cushioned on trapped column of air.
Release air from the mast to give the rate of descent required.
(7) All Hilomast compressors are fitted with either manually or electrically operated
exhaust valves and it may be more convenient to lower the mast through these.
(8) When the mast is required to operate on only one or two sections, it is only
necessary to unclamp those sections.
(9) Locking the top section or sections in the retracted position will allow the
shortened mast to operate in higher wind speeds.