FORM 160.52-O1
31
YORK INTERNATIONAL
SECTION 3
SYSTEM OPERATING PROCEDURES
WARNING
OIL HEATERS
If the oil heater is de-energized during a shutdown pe-
riod, they must be energized for 12 hours prior to start-
ing compressor, or remove all oil and recharge compres-
sor with new oil. (See Charging Unit With Oil, page 44.)
OIL HEATER OPERATION
The oil heater operation is controlled by the MicroCom-
puter Control Center. The heater is turned on and off to
maintain the oil temperature to a value 50 degrees F
above the condenser saturation temperature. This is
the target value and if the oil temperature falls to 4 de-
grees F or more below the target, the heater is turned
on. It is turned off when the oil temperature increases
to 3 degrees F above the target value.
If the target value is greater than 160°F (71°C), the
target defaults to 160°F (71°C). If the target value is
less than 110°F (43.3°C), it defaults to 110°F (43.3°C).
To prevent overheating of the oil in the event of a con-
trol center component failure, the oil heater thermo-
stat (1HTR) is set to open at 180°F (82°C).
CHECKING THE OIL LEVEL IN THE OIL
RESERVOIR
Proper operating oil level the upper and lower sight
glasses.
If the oil is excessively high after start-up, the excess
oil may be drained from the oil filter drain valve while
the compressor is running.
If oil level is low, oil should be added to the compres-
sor. (See Charging Unit With Oil, page 44.)
CAUTION: Comply with EPA and Local regulations
when removing or disposing of Refrigera-
tion System oil!
START-UP PROCEDURE
PRE-STARTING
Prior to starting the chiller, observe the MicroComputer
Control Center. Make sure the display reads
SYSTEM READY TO START
.
To pre-start the chiller, use the following procedure:
1. Oil Heater The oil heater must be energized for
12 hours prior to starting the chiller. The unit will
not start if the oil is less than 71°F (22°C). If not
possible the compressor oil should be drained and
new oil must be charged into the oil sump. (See
Charging Unit With Oil, page 44.)
2. Oil Pump To check, press and release the
MANUAL OIL PUMP
key under
Service
on the
Control Center. The oil pump will run for 10 min-
utes and shut down. Press and release the
MANUAL OIL PUMP
key to stop the operation of
the oil pump for less than 10 minutes of operation.
3. Pre-Rotation Vanes To perform this test the
starter interlock terminals 3 and 4 must be jum-
pered to allow vanes to open (remove the jumper
after test). Make sure the Control Center is in the
SERVICE
mode, then press the prerotation vanes
OPEN
and
CLOSE
keys to observe the operation
of the prerotation vanes. The Control Center sup-
plies a signal to operate the prerotation vanes. The
movement of the vanes will be displayed on the
Control Center. The display readout is active when-
ever power is supplied to the Control Center. Re-
turn from the
SERVICE
mode to
LOCAL
,
PRO-
GRAM
, or
REMOTE
mode to suit the method of
operation selected for the chiller application. Refer
to Section 2.
4. % Current Limit Press the
% CURRENT LIMIT
setpoint key on the Control Center. The Display
should read
CURRENT LIMIT = 100% FLA
on (Solid
State Starter units only, the display is
CURRENT LIMIT = 100% FLA, MTR CUR = XXXX FLA
)
if the Control Center was not programmed. If the
setpoint is not 100% and was predetermined for
the job application the Control Center should be
programmed to that specification. To program, re-
fer to Section 2.
5. All Control Center setpoints should be programmed
before the chiller is started. (Refer to Section 2.)
Prior to start, the clock must be programmed for
the proper day and time. Any setpoints which are
desired to be changed may be programmed. If not
programmed the default value setpoints are as
follows:
LCWT = 45°F (7.2°C)
% Current Limit = 100% FLA
Pulldown Demand = None
Clock = Sun 12:00 A.M.
Daily Schedule = None
Holiday = None
Remote Reset Temp. Range = 20°F (11°C)
Data Logger = No operation
