Water flow through the oi l cooler is manually ad justed by a plug valve (It em 9) to maintain the
oil at an operating tempe rature of approximate ly 145 F (63 C). During shutdown , t he oi l
temperature is also maintained a t 150 to 160 F (65 to 71 C) by an immers ion heater (Item 3) in
order to minimize absorp tion of refrigerant by th e oil.
Upon leaving the oil coo ler , the oil is filtered (11) and a po rtion is directed to the se al- e nd
bearing (17) and the shaft sea l (18). The re mainder lubricate s the compressor transmission (15)
and the thrust and journal bearings (10). Thrust bea ring temperature is indi cated by the PIC
controls. Oil from both circuits returns by gravity to the reservoir.
A demister (13 and 16), by cen trifugal action, draws r ef rigerant gas from the tr ans m i ssion
area to a housing that is ve nt ed to the cooler (Item 19). T he r es u lting pressure diffe r enc e
prevents oil from the tra nsmission cavity from lea king into the seal.
The open compressor driv e r eq uires that the shaft seal (18) be kept full of lubrica ti on oil,
even when the machine is not operating, to prevent los s of refrigerant.
If the machine is not operat ing and the oil pump has not op erated during the last 12 ho urs,
the control system will automatically run the oil pump for one minute in order to keep the contact
seal filled with oil.
IMPORTANT: If the co ntrol power is to be deenerg i zed for more than one day, the
machine refrigerant should be pumped over to the utility vessel.