Specifications

YORK INTERNATIONAL 27
FORM 160.48-O1
MON XX:XX AM – HIGH LINE VO LTAG E
(Solid State Starter Applications Only)
Chiller is shut down because the voltage in any phase
of line voltage has increased above the over-voltage
threshold for 20 consecutive seconds. Refer to expla-
nation under “System Setpoints - SSS Motor Current/
Volts”, page 8. The system will automatically restart
when all phases of line voltage decrease to the maxi-
mum allowable line voltage to start the chiller.
MON 09:30 AM LOW OIL TEMPERATURE – AUTOSTART
Whenever the oil temperature falls below 55°F, or the oil
temperature sensor is disconnected from the Micro
Board, the preceding message will appear. The system
will automatically restart when the display indicates 71°F.
MON XX:XX AM FAULTY DISCHARGE TEMP SENSOR
Whenever the discharge temperature falls below 32°F,
or the discharge temperature sensor is disconnected
from the Micro Board, the preceding message will ap-
pear. To restart the system when the discharge tem-
perature rises or the sensor has been connected, press
the “COMPRESSOR” switch to the “STOP/RESET” po-
sition and then to the “START” position.
FIG. 16 - MICROCOMPUTER CONTROL CENTER - INTERIOR - WITH PANEL OPEN - LOCATION OF REAL TIME
CLOCK U16 RTC IC CHIP
MON XX:XX AM – AUX SAFETY SHUTDOWN
The system is shut down because an external device,
connected to digital input board TB1-31 (Aux Safety
Shutdown Input), has initiated a system shutdown. This
input is a general purpose input that can be used to
annunciate a user-defined safety shutdown. To restart
chiller, press “COMPRESSOR” switch to “STOP/RESET”
position and then to the “START” position.
REPLACE RTC, U16 – REPROGRAM SETPOINTS
Indicates that the battery located inside the REAL-TIME
CLOCK IC Chip (U16 on the Micro Board) is defective.
This battery provides back-up power to the RTC memory
(RAM) in the event of a utility AC power failure. This
assures the system setpoints will be maintained. If this
message appears, the RTC IC Chip (U16) on the Micro
Board must be replaced. If there had been a power failure
while this message is displayed, the setpoints will have
been lost and must be reprogrammed. Order a replace-
ment RTC IC Chip (YORK part number 031-00955-000)
from the YORK Parts Distribution Center. With AC power
removed from system, locate RTC Chip U16 on the Micro
Board and remove existing RTC Chip from socket and
discard. Observe anti-static precautions and install new
RTC Chip in socket. Assure proper IC orientation - orien-
tation notch must be UP. (Refer to Fig. 16)
24673A
MICRO BOARD
U16 RTC 1C CHIP
REAL-TIME CLOCK