Technical data

6.7 Prolonged Shutdowns
If the unit is to be shut down for an extended period of
time (for example, over the winter season), the following
procedure should be followed:
1. If freezing temperatures are likely to be
encountered while the system is idle, carefully
drain the cooling water from the cooling tower,
condenser, condenser pump, and the chilled water
system, chilled water pump and evaporator. Open
the drains on the evaporator and condenser liquid
heads to assure complete drainage. If a Solid State
Starter is fitted drain water from starter cooling
loop.
2. Move the jumper on the microprocessor board to
the OFF position to conserve the battery (see
control panel Operation Instruction).
3. Open the main disconnect switches to the
compressor motor, condenser water pump and the
chilled water pump. Open the 115 Vac circuit to the
control panel.
To return the unit to operation is the reverse of this
procedure, however, after a prolonged shutdown it will
be necessary to replace all of the oil and install a new oil
filter element. This should only by done by suitably
qualified personnel.
6.8 Operating Inspections
By following a regular inspection schedule any potential
problems with the unit can be identified early and
attended to before serious operating difficulties occur.
The following list of inspections and procedures should
be used as a guide. In all cases the inspections should
only be carried out by properly trained personnel. If a
problem is identified, no attempt should be made to
carry out any repairs unless properly qualified and
equipped to do so. Where appropriate, refer to the
control panel Operation Instruction for correct keypad
operation to access data on the control panel display.
Daily
1. Check the bearing oil pressure: The actual
bearing oil pressure will vary with compressor
suction and discharge pressures. When a new
system is first operated under normal full load
conditions, the bearing oil pressure should be
recorded as a reference point with which to
compare subsequent readings.
2. Check Oil Pressure Display: The oil and oil filter
transducers are compared during compressor
operation. If the differential filter pressure exceeds
138 kPa for 8 seconds, the message WARNING -
OIL - DIRTY FILTER is displayed. If the differential
filter pressure exceeds 172.5 kPa for 8 seconds,
the unit shuts down and the displayed message is
OIL - CLOGGED FILTER. A gradual decrease in
bearing pressure of 30 to 60 kPa (with constant
suction and discharge pressures) may be an
indication of a dirty filter. The filter should be
replaced when pressure loss is 30% of the original
pressure.
3. Check the oil level in the oil separator reservoir:
The correct oil level is half way up the sight glass
but this may vary depending on load. The level
should not disappear from the sight glass.
4. Check entering and leaving condenser water
temperatures and condenser pressure for
comparison with design conditions.
5. Check the entering and leaving chilled liquid
temperatures and evaporator pressure for
comparison with design conditions.
6. Check the compressor discharge temperature:
During normal operation discharge temperature
should not exceed 100°C.
7. Check the compressor motor voltage and
current: At the Electro Mechanical Starter or on the
control panel display for units with a Solid State
Starter.
8. Check for any signs of dirty or fouled
condenser tubes. The temperature difference
between water leaving the condenser and the
liquid refrigerant leaving the condenser should not
exceed the difference recorded for a new unit by
more than 2.2°C.
9. Check water treatment is correct.
10. Read any warning or safety shutdown messages
displayed.
160.81-ICOM-GB0 (01/02) 6-3