York YT ユーザーズマニュアル

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FORM 160.55-O1 (604)
131
YORK INTERNATIONAL
Hz immersion type. A separate three phase pow er sup-
ply is required except when ordered with a YORK Solid 
State Starter or Variable Speed Drive. A gravity ß ow oil 
res er voir  is  pro vid ed to feed the bearings and gears dur-
ing coast down in the event of a power failure.
CAPACITY  RE DUC TION - Prerotation vanes (PRV) 
mod u late the unit capacity from 100% to 10% of de sign, 
on normal air conditioning jobs. The prerotation vanes 
are air foil-shaped and made of man ga nese bronze. An 
external,  electric  PRV  operator  au to mat i cal ly  con trols 
the vane position through a sim ple, re li able link age. 
SHAFT SEAL - The com pres sor drive shaft seal 
con sists of a spring-loaded, pre ci sion lapped car bon 
ring, high tem per a ture elastomer O-ring static seal, and 
stress-re lieved, pre ci sion lapped cast iron collar. The 
seal fea tures a small face area and low rub bing speed. It 
pro vides an ef Þ  cient seal under bothVacuum and pres-
 sure conditions. The seal is oil-ß ooded at all times and 
is  pres sure-lu bri cat ed  dur ing  compressor  op er a tion. 
OPEN MO TOR - The 3600 RPM open motor is a 
drip-proof, squir rel cage, induction type constructed 
to YORK design speciÞ cations  by  na tion al ly-known 
man u fac tur ers.  Stan dard  low  voltage  (208  through 
600V-3Ph-60/50 Hz) motors are available for full-volt-
 age (across-the-line) or re duced-voltage (solid state, star 
delta or auto transformer) start ing. Standard high volt age 
(2300 through 4160V-3Ph60/50 Hz) motors are avail able 
for full-volt age (across-the-line) or reduced-volt age (pri-
 ma ry  re ac tor  or  auto  trans form er) starting. Open close 
cou pled motors are built with a cast iron adapter ß anged 
be tween the motor and compressor. This unique de sign 
allows the mo tor to be coupled to the com pres sor. 
MOTOR  TER MI NAL  BOX - The casing is fab ri -
cat ed of heavy gauge steel. There are six terminals 
(three for high volt age) in the terminal box. Provisions 
are fur nished for 208 through 600 volts for three-lead 
types of starting (solid state, across-the-line, and auto 
trans form er). Mo tor terminal lugs are furnished with 
the YORK Current Guard Starter and the Variable 
Speed Drive mount ed in the pow er section. Over load/
overcurrent trans form ers (CTs) are fur nished as listed 
below; in motor ter mi nal box, as fol lows:
5
CASING - The casing is ac ces si ble with ver ti cal cir cu lar 
joints and fab ri cat ed of close-grain cast iron. The mo tor 
as sem bly  is  com plete ly removable from the com pres sor 
rotor and scroll assembly. Com pres sor cast ings are de-
 signed for 15 PSIG working pres sure and hy dro stat i cal ly 
pressure tested at 50 PSIG. 
COMPRESSOR - The rotor assembly consists of a 
heat treated alloy steel drive shaft (integral with pin ion 
gear) and a light weight, high strength, fully shroud ed 
cast alu mi num impeller. The impeller is designed for 
bal anced  thrust.  The  im pel ler  is  dy nam i cal ly  bal anced 
to in sure vi bra tion free op er a tion and is overspeed test ed 
for safe ty. 
BEARINGS - Insert type journal and thrust bearings 
are  fab ri cat ed  of  alu mi num  alloy  and  are  precision  bored 
and  ax i al ly  grooved. 
INTERNAL GEARS - Single he li cal gears with 
crowned teeth are em ployed so that more than one tooth 
is in con tact at all times to pro vide even dis tri bu tion of 
the compressor load with quiet operation. Gears are in te -
gral ly as sem bled in the compressor rotor sup port and are 
oil Þ lm  lu bri cat ed.  Each  gear  is  in di vid u al ly  mount ed  in 
jour nal bearings with individual thrust bear ings to in sure 
prop er bal ance of forces from the im pel ler and mo tor. 
LUBRICATION SYS TEM  -  YORK  lu bri cat ing  oil 
is force fed to all bear ings and Þ ltered by an ex ter -
nal ly mounted 15 mi cron replaceable car tridge oil 
Þ lter equipped with service valves. An au to mat ic oil 
re cov ery sys tem re turns oil to the com pres sor that has 
mi grat ed into the re frig er ant system. Heat is re moved 
from the oil by a re frig er ant-cooled oil cooler, located 
in the evap o ra tor. All oil piping is completely factory-
in stalled and test ed. A thermostatically con trolled heater 
is sup plied in the oil res er voir to limit the amount of 
re frig er ant ab sorbed by the oil when the compressor is 
not  op er at ing.
Oil (under pressure) is supplied from the oil reservoir by 
an internally-mounted sub mers ible oil pump. Oil Pump 
motors are available in 208 through 600V-3Ph-60/50 Hz 
to match the application and are supplied com plete with 
starter and current sensing overloads for ex tra pro tec tion. 
The oil reservoir heater is 1000 watts, 115V-1Ph-60/50 
SECTION 5
SYSTEM COMPONENTS DESCRIPTION -
COMPRESSOR / MOTOR ASSEMBLY