Details
Oil is charged into the reser voir (Item 1) t hrough a hand v alve (Item 4) which also func tions
as an oil drain. If there is r ef rigerant in the machine , a pu mp is required for chargin g. Sight
glasses (Item 10) on the rese rvoir wall permit observ at ion of the oil level. The normal operating
oil level is from the mid dle of the lower sight glass to th e top of the lower sight gla s s .
The motor-driven oil pum p ( I tem 8) discharges oil to an oil cooler (Item 12) at a rate and
pressure controlled by an oil regulator (Item 7). The differential pressure (supply versus return)
is registered at the cont r ol center. Oil different ia l pressure is maintaine d between 18 to 30 psi
(124 to 207 kPa).
The oil pump discharges oil t o the oil cooler (Item 12). Oi l is then piped to the oil filt er
assembly (Item 9). This fi lter is capable of being va lv ed closed to permit removal of the filter
without draining the entire oil system (see Scheduled Maintenance, Changing Oil Filter section
for details). The oil is th en piped to the oil cooler ( It em 12 ).
The oil cooler on the EX com pr es s o r is a plate-and-frame t y pe, refrigerant cooled, hea t
exchanger. The EX compre ssor oil cooler heat exc ha nger uses refrigerant from the condenser
as a coolant. The refriger a nt cools the oil to a temper at ure between 110 and 120 F (43 and
49 C) supply oil tempera tu re to the bearings.
The FA compressor oil coole r heat exchanger is wat er c ool ed. The water flow thro ugh the
cooler is manually cont rolled by a plug valve. The va lv e s ho uld be adjusted to main ta in
approximately 145 F (63 C) in the oil sump during runn ing conditions.