Abacus Lighting, Sutton-in-Ashfield, Nottinghamshire, NG17 5FT, England. Tel: (+44) 01623 511111, www.abacuslighting.com
12
3.7.
Removing the Ram
CHECK THAT THE MAST IS PROPERLY DOCKED AND THE BEARING PLATES ARE IN
THEIR LOCKED POSITION.
The ram removal procedure differs between the HL250 and HL330 masts.
3.7.1.
HL250 Mast
Remove the upper ram anchor pin and ease the ram out from between the gussets. Refit the
anchor pin and retaining clip. Support the ram against the mast and operate the control valve
(RLH5) or operate the manual pump (RLH7) until the ram is fully closed. Remove the
retaining clip and lower ram anchor pin and place conveniently near the pump unit. Remove
the ram from the mast and locate it on the gusset welded to the trolley unit. Support the ram
and fit the lower anchor pin through the ram and gusset. Secure with the retaining pin. Lean
the ram forward into its storage position. Disconnect from the electrical supply and stow the
cable. Refit the mast door.
The hydraulic system should be depressurised prior to storage (see 3.7.3).
3.7.2.
HL330 Mast
Pull out the retaining pin and remove the upper ram anchor pin. Pull the ram out from
between the gussets and refit the anchor and retaining pin. Support the ram against the
column and operate the control valve to retract the ram. Release the control valve when the
ram is about 100mm short of being fully closed. Offer the lower location bracket on the
counterbalance up to the ram support/lifter bracket by swinging the ram backwards and
tilting the motor/pump unit handles upwards as necessary. With the weight of the ram
supported on the counterbalance, release the lower ram anchor pin and pull the unit away
from the mast. Refit the pin to the ram and secure with its retaining pin. Fully close the ram to
engage the upper anchor pin in the location bracket on the counterbalance. The ram must be
fully closed with the ram anchor pin fitted to securely fix it to the motor pump unit.
Switch off the electric motor and disconnect the power supply. Refit the door cover to the
mast, and secure with the retaining screw.
The hydraulic system should be depressurised prior to storage (see 3.7.3).
3.7.3.
Depressurising Procedure
During periods of storage the hydraulic circuit, comprising the ram, pump and hoses, should
be fully depressurised.
To depressurise the system, disconnect the counterbalance from the power supply and
operate the control lever forwards and backwards a number of times. The hoses should
visibly relax and the pressure gauge will drop to zero.
