EXTENDED SHUTDOWN
1.
2.
1.
2.
3.
4.
5.
Move the Circuit 1 and Circuit 2 switches to the “Pump-
down and Stop” position. After the compressors have shut
off, open the remote stop switch and the controller will stop
the chilled water pump.
3. Close the manual liquid line shutoff valves.
4. Close the compressor suction and discharge service valves
and oil equalization valves on four compressor units.
Move the system switch to the “Emergency Stop”
posi-
tion and turn off main power to the chiller and the chilled
water pumps.
5. Tag all opened electrical disconnect switches to warn
against startup before opening the compressor
sucton,
discharge and liquid line service valves.
STARTUP AFTER EXTENDED SHUTDOWN
Inspect all equipment to see that it is in satisfactory At this point is will be necessary to complete
MicroTech
operating condition.
pre-start checkout found in
IM
493 before system
opera-
Remove all debris that has collected on the surface of the
condenser coils (remote condenser models).
Open the compressor suction and discharge valves until
backseated. Always replace valve seal caps.
Open the manual liquid line shutoff valves.
Allow the crankcase heaters to operate for at least 12 hours
prior to startup.
iion is attempted. After
MicroTech
pre-start checkout and
startup is complete be sure to complete the following
mechanical startup requirements.
8
After running the unit for a short time, check the oil level
in each copressor crankcase and for flashing in the
refrigerant sightglass (see Maintenance section).
SYSTEM MAINTENANCE
GENERAL
To assure smooth operation at peak capacity and to avoid
damage to package components, a program of periodic in-
spections should be set up and followed. The following items
are intended as a guide to be used during inspection and must
be combined with sound refrigeration and electrical practices
to assure trouble-free performance.
The liquid line sightglass/moisture indicator on all circuits
must be checked to be sure the glass is full and clear and
the moisture indicator indicates a dry condition. If the indicator
shows that a wet condition exists or if bubbles show in the
glass, even with a full refrigerant charge, the filter-drier ele-
ment must be changed.
Water supplies in some areas may tend to foul the water
cooled condenser to the point where cleaning is necessary.
The fouled condenser will be indicated by an abnormally high
condensing pressure and may result in nuisance tripouts. To
clean the condenser, a chemical descaling solution should
be used according to the manufacturer’s directions.
Systems with remote air cooled condensers require periodic
cleaning of the finned surface of the condenser coil. Cleaning
ing may be accomplished by using a cold water spray,
brushing, vacuuming, or high pressure air. No tools should
be used that could damage the coil tubes or fins.
A lead-lag switch is provided on all multiple compressor
models to permit even distribution of wear on the com-
pressors. This switch should be turned on on an annual basis.
The compressor oil level must be checked periodically to
be sure the level is at the center of the oil sightglass. Low
oil level may cause inadequate lubrication and oil failure
switch tripout. If the oil level is low and oil must be added,
use oils referred to in “Compressor Oil Level” section below.
A pressure tap has been provided on the liquid line
downstream of the filter-drier and solenoid valve but before
the expansion valve. An accurate subcooled liquid pressure
and temperature can be taken here. The pressure read here
could also provide an indication of excessive pressure drop
through the filter-drier and solenoid valve due to a clogging
filter-drier.
NOTE: A normal pressure drop through the solenoid valve
is approximately 3 psig at full load conditions.
CONTROL CENTER ELECTRICAL SERVICE
The electrical control center is relativelv easv to service since
service on the control center:
indicator lights are provided to show unit status. Determine
that the problem is actually in the control panel before
proceeding.
1.
Study the wiring diagram so that you understand the opera-
tion of the SEASONPAK water chiller.
By referring to the schematic wiring diagrams, the trouble
can be isolated to a particular section of the panel.
WARNING: Warranty is voided if wiring is not in accordance
with specifications. A blown fuse or tripped protector indicates
a short ground or overload. Before replacing fuse or restar-
ting compressor, the trouble must be found and corrected.
It is important to have a qualified control panel electrician ser-
vice this panel. Unqualified tampering with the controls can
cause serious damage to equipment and void the warranty.
The following steps should be taken prior to attempting any
2.
Before investigating trouble in the control center, check for
burned out light bulbs by testing across the appropriate
terminals.
CAUTION: The panel is always energized to ground
even though the system switch is off. If it is necessary to
de-energize the complete panel including crankcase
heaters, pull main disconnect.
If motor or compressor damage is suspected, do not restart
until a qualified serviceman has checked the unit.
IM 508 I Page 43
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