Routine Maintenance; Protective Shutdown System; Low Engine Oil Pressure Switch; Temperature Switch(Es) - Doosan 7/53R Operation And Maintenance Manual

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26
MAINTENANCE

ROUTINE MAINTENANCE

This section refers to the various components which require periodic
maintenance and replacement.
The
SERVICE/MAINTENANCE CHART indicates the
components' descriptions and the intervals when maintenance has to
take place. Oil capacities, etc., can be found in the GENERAL
INFORMATION section of this manual.
For any specification or specific requirement on service or preventative
maintenance for the engine, refer to the Engine Manufacturer's
Manual.
Compressed air can be dangerous if incorrectly handled. Before doing
any work on the unit, ensure that all pressure is vented from the system
and that the machine cannot be started accidentally.
If the automatic blowdown fails to operate, then pressure must be
gradually relieved by operating the manual blowdown valve. Suitable
personal protective equipment should be worn.
Ensure that maintenance personnel are adequately trained, competent
and have read the Maintenance Manuals.
Prior to attempting any maintenance work, ensure that:-
all air pressure is fully discharged and isolated from the system. If
the automatic blowdown valve is used for this purpose, then allow
enough time for it to complete the operation.
the discharge pipe / manifold area is depressurised by opening the
discharge valve, whilst keeping clear of any airflow from it.
MINIMUM PRESSURE VALVE - WHEN FITTED
NOTE: Pressure will always remain in the part of the system between
the minimum pressure valve and the discharge valve after operation
of the auto blowdown valve.
This pressure must be relieved by carefully:
a) Disconnecting any downstream equipment.
b) Opening the discharge valve to atmosphere.
c) (Use hearing protection if necessary).
the machine cannot be started accidentally or otherwise, by posting
warning signs and/or fitting appropriate anti-start devices.
all residual electrical power sources (mains and battery) are
isolated.
Prior to opening or removing panels or covers to work inside a
machine, ensure that:-
anyone entering the machine is aware of the reduced level of
protection and the additional hazards, including hot surfaces and
intermittently moving parts.
the machine cannot be started accidentally or otherwise, by posting
warning signs and/or fitting appropriate anti-start devices.
Prior to attempting any maintenance work on a running machine,
ensure that:-
the work carried out is limited to only those tasks which require the
machine to run.
the work carried out with safety protection devices disabled or
removed is limited to only those tasks which require the machine to
be running with safety protection devices disabled or removed.
all hazards present are known (e.g. pressurised components,
electrically live components, removed panels, covers and guards,
extreme temperatures, inflow and outflow of air, intermittently
moving parts, safety valve discharge etc.).
7/53, 7/53R
appropriate personal protective equipment is worn.
loose clothing, jewelry, long hair etc. is made safe.
warning signs indicating that Maintenance Work is in Progress are
posted in a position that can be clearly seen.
various
Upon completion of maintenance tasks and prior to returning the
machine into service, ensure that:-
the machine is suitably tested.
all guards and safety protection devices are refitted.
all panels are replaced, canopy and doors closed.
hazardous materials are effectively contained and disposed of.

PROTECTIVE SHUTDOWN SYSTEM

Comprises:

Low engine oil pressure switch

High airend discharge temperature switch
High coolant temperature switch
Alternator/drive belt failure circuit.
LOW ENGINE OIL PRESSURE SWITCH
At three month intervals, test the engine oil pressure switch circuit as
follows:
Start the machine.
NOTE: Do not press the load button.
Remove a wire from one terminal of the switch. The machine should
shutdown.
At twelve month intervals, test the engine oil pressure switch as
follows:-
Remove the switch from the machine.
Connect it to an independent low pressure supply (either air or oil).
The switch should operate at 1,0 bar.
Refit the switch.

TEMPERATURE SWITCH(ES)

At three month intervals, test the temperature switch circuit(s) as
follows:
Start the machine.
NOTE: Do not press the load button.
Disconnect each switch in turn. The machine should shutdown.
Re-connect the switch.

HIGH AIREND DISCHARGE TEMPERATURE SWITCH(ES)

At twelve month intervals, test the high airend discharge temperature
switch(es) by removing it from the machine and immersing in a bath of
heated oil. The switch should operate at 120°C. Refit the switch.

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