5. STARTING AND STOPPING
THE
COMPRESSOR PACKAGE
5.1 START-UP
After all the installation functions covered în chapter
4
have
been completed, it will be possible to perform start-up ser
vice. lt is necessary that key plant operating personnel be
available to go through the start-up. since a great deal of
knowledge can be obtained in this manner. The operatións
covered in this chapter will be pertormed at start-up under
the supervision of a Grasso Refrigeration Representative.
IMPORTIWT
See Paragraph 4.2 before scheduling start-up.
5.2 PRE-START CHECK UST
,,.---
The following Paragraph covers only the initial start of the
compressor and not t'he remainder of the refrigeration sys
tem. Be sure that all necessary system valves
are
open and
1t the refrigeration system is ready for start-up. Use the
rollowing check list to guarantee that no items of importance
regardin9 the compressor package have been overlooked.
a) Package is charged wîth refrigerant.
b) Motor starter breaker disconnected from the electric
supply line.
c} Safety switches set to the values in paragraph 4.14.
d) All
safety switches verified for correct operation.
e) The oil in the separator sump îs 20
·c
or 5.5
·c
above
saturation temperature ot the package pressure
whichever ,is hlgher (at least two hours prîor to start
up).
f) Oil level established in sight glass.
g) Coating water to oil cooler turned on if water cooled.
h) Liquid refrigerant supply to compressor on if super
feeded.
Stop vafves to the pressure gauges are open.
+<) Suction stop valve still closed and discharge stop
valve fs open.
1) Coupling tums freely by hand (coupling guard still not rn
stalled).
m) Direction of drive motor and oil pump rotation (shown
on the oil pump name plate) c
h
ecked
,
n) Capacity control actuator indicator at minimum.
o) Capacity control selection switch in manual.
p) Starting switch in the �Manual-Reset" position,
q) Consult the contractors plant operation manual.
When the above items are verified, the compressor is ready
for the initia! start.
5.3 ST ARTING THE COMPRESSOR PACKAGE
hen starting the compressor package. a distinction should
be
made between:
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BEDIENNaSVOOFISOfRFTl'BEmiEes,.Nu;JTUNÇ
lNSTRtJC1'10HMAHUAL,111.ANIM:L0'1NSlRICl10t(
1
)
Starting the compressor for the firs1 time after the
plant has been delivered ready to operate.
For manually controtled plants as well for these opera
ting al.ltomatically, 1he starting procedure glven in the
instructions hereafter [steps a) through g)] should
be
fol
lowed exactly.
2) Restarting the compressor in a plant already oper
ational.
In the case of rnanually controlled pJanls, proceed in ac
cordance with the fnstructions given in the contractors
plant manual.
In the case of automatlçally operating plants, the starting
procedure is incorporated in the control system and it
does not gene-rally require, therefore, any particular care.
IMPORTANT
Compressors refifled wffh o;t rèturned to the stator d1:Je to a
total current break down, may never: be restarted automat
ically. To prevent Jiquid hammer it is necessary to restart
the compressor manually again.
3) Restarting the compressor after the plant has been
out of operation tor a long period of time (e.g. on ac
count of seasonal stands1ill or maintenance work).
For manually controlled plants as well as for those opera
üng automatfcally, proceed 1n accordance with 1he in
structions given under steps a) through g).
The starting procedure is as fellows:
a) Start the compressor after removing the fuses of the
compressor drive motor (only the lubrication oil pump
is in operation) to ensure that the entire oil system
(together With the shaft seal housing) is filled with oil.
b) Stop the compressor again after about 30 seconds
and rota te the compressor drive shaft a few turns by
hand in order to allow
excess
of oîl to escape
trom
the
compressor housing into the oil separator.
c) Definitely install the coupling guard.
d) Refit the drive motor fuses.
e) Start the compressor. Stowly open the suction stop
valve (be careful that no liquid Çqrry-over occurs, es
pecially in plants with lower suction lines). Run the
compressor at îts lowest capacrty setting tor a half
hour and check whether all pressure gauge readings
are normal. During starting and tor a period no langer
than 20 minutes thereafter, then oil temperature is
allowed to be below the minimum limit of 40
·c,
but
never below 20
·c.
f) Set thé capacity control to the required positlon. This set
ting is visible on the scate of the Indicator plate behind
tt,e wîndow of the actuator control cover.
lf necessary. check the control all over the whofe range.
o) lf ::iv::iil;:ihlP., !=:Witch over to automatic operation.
After the compressor has run fully automatically for an
hour and the pressures and temperatures have re
maîned stable tor 15 mînutes, list all readings in a
data record. In this way, any deviations trom the cor
rect operating conditions can be found easily.
92.01
Cotnpressot Package GSLP
Page5.1
