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System Calibration
the displayed Refrigerant Level Po si tion. If not
100%, fi nely adjust the "S" (span) screw until
100% is displayed. Do not over-adjust! Observe
display update delay as de scribed in step 4.
8. Due to possible interaction of "Z" and "S" ad just -
ments, recheck level percentage display on the
RE FRIG ER ANT LEVEL CONTROL Screen at
min i mum and maximum refrigerant levels.
9. Seal the Level Sensor calibration screws with a
small amount of sealant.
10. Replace the Level Sensor cover plate.
11. On the REFRIGERANT LEVEL CONTROL
Screen, select AUTO Level Control op er a tion.
OIL PUMP VARIABLE SPEED DRIVE
On certain model chillers, the oil pump is driven by a
small Variable Speed Drive. A complete description of
the Drive op er a tion and the Setpoints that affect this
con trol are provided in the "Oil Pump Vari able Speed
Drive" section of this book. The Setpoints are listed be-
low. The Program Vari able Speed Drive op er a tion must
be EN ABLED and the Setpoints pro grammed us ing the
pro ce dures below. Also, the Oil Pump Speed can be
manually con trolled using the procedure below.
Enable/Disable:
The Oil Pump Variable Speed Drive Pro gram op er a tion
must be enabled with Microboard Pro gram Switch SW1-
2 as fol lows:
SW1-2 ON - Enabled
OFF - Disabled
Setpoints:
The following are the Setpoints and range of pro-
gram ma ble values. The DEFAULT values (shown in
pa ren the sis) are the rec om mend ed values and should
pro vide prop er operation in most applications. How ev er,
the Setpoints can be programmed to other values as re-
quired. Enter Setpoints using procedure below:
a. Oil Pressure Setpoint - 20 to 45 PSID (35)
b. Control Period – 0.3 to 2.7 seconds in 0.3 sec ond
increments. (0.3)
1. At the Keypad, log in at SERVICE access Level
using access code 1 3 8 0.
2. Select OIL SUMP Screen.
3. On the OIL SUMP Screen, press the ap pro pri ate
key to select the Setpoint to be programmed.
4. If the Dialog box begins with the word "Enter",
142
use the numeric keypad keys to enter the desired
val ue. If it begins with "Select", use the ◄ and ►
keys to select desired value.
5. Press ENTER (✔) key.
Manual Control:
The Oil Pump speed can be manually controlled be tween
25 and 60(50) Hz as follows:
1. At the Keypad, log in at SERVICE access level
us ing access code 1 3 8 0.
2. Select OIL SUMP Screen.
3. The speed can be increased and decreased in 0.5
Hz increments using the RAISE and LOW ER
keys. Each time the key is pressed, the frequency
is changed 0.5 Hz.
OR
The speed can be set to a specifi c frequency, as pro-
grammed by the SET key as follows:
1. Press SET key.
2. Use the numeric keys to enter the desired val ue.
3. Press ENTER (✔) key.
4. If the AUTO key is pressed, automatic speed con trol
is invoked.
STANDBY LUBRICATION
To maintain oil seal integrity while the chiller is shut-
down, a feature can be enabled that turns on the Oil
Pump for 2 minutes every 24 hours if the chiller has
not been run in the past 24 hours. While the Oil Pump
is running, STAND BY LUBE IN PROCESS, along
with a count down timer displaying the time remain-
ing in the lube cy cle is displayed. If the chiller is style
"D" equipped with an Oil Pump Variable Speed Drive,
the operating oil pres sure will be the programmed Oil
Pres sure Setpoint.
If at least 15 PSID of oil pressure is not achieved with in
30 seconds of turning on the Oil Pump, the cycle is ter mi -
nat ed and WARNING - STANDBY LUBE - LOW OIL
PRESSURE is displayed and no more stand by lu bri ca -
tions will occur until a.) the FAULT AC KNOWL EDGE
keypad key is pressed after login at SERVICE access
level, at which point another lube cycle will be attempted
or b.) the chiller is started.
Standby lubrication cycles will not be performed if ei ther
oil pressure transducer is reading a pressure out of its
range (HOP < 6.8 PSIG; LOP < 0 PSIG). This as sures
that the oil pump will not be turned on with the shells
at at mo spher ic pressure, as they would be during main-
te nance.
FORM 160.54-M1(503)
YORK INTERNATIONAL
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