As the oil leaves the oil cool er, it passes the oil press ur e t ransducer (Item 14) and the n the
thermostatic expansi on valve bulb (Item 13) . T he oi l flow is then divided, and a portion flows to
the motor-end bearing (Item 19) and seal. The rema ind er lubricates the comp r es s or
transmission (Item 2) and t he thrust and journal bear in gs (Item 3). Thrust beari ng temperature
is indicated at the Local I nterface Device (LID). Oi l from each circuit retur ns by gr av i ty to the
reservoir.
A demiste r (Items 17 and 18), by c en t rifugal act ion, draws ref r igerant gas fr om t h e
transmission are a to the motor shell. The resu lting pressure d ifference preven ts oil in the trans-
mission cavity from leaking into the motor shell.
Several safety featu r es ar e pa rt of the lubrication sy ste m:
In the event of power failur e , a small oil reservoir (Ite m 16) supplies sufficient oil reserve to
ensure continued lubrication unt il all compres sor parts have co me to a comple te stop. The
bearing temperat ure sensor (Ite m 15) monitors t hrust bearing te mperatures and sh uts off the
machine if the tempera tu re rises above a selected po int. Low-oil pressure wi ll shut down the
machine or prevent a sta r t if oil pressure is not adequate.
The PIC (Product Integrated Control) measures the temperature of the oil in the sump and
maintains the temper at ure during shutdown (see Co ntrols, Oil Sump Tempe r at ure Control
section). This tempe r at ure is read on the LID default s c r een .