Troubleshooting; Causes Of Normal And Safety System Shutdowns - York Millennium YK M3 M3 G4 THRU YK S6 S4 J2, YK LB LB G4 THRU YK SE SC J4 Operating & Maintenance Manual

TABLE 1 – CAUSES OF NORMAL AND SAFETY SYSTEM SHUTDOWNS IN ACCORDANCE WITH THE MICROCOMPUTER CONTROL,
CENTER DISPLAY
SHUTDOWN CAUSE
CONTROL CENTER DISPLAY
DAY OF TIME OF CAUSE OF
WEEK DAY SHUTDOWN
MON. 10:00 AM Low Water
Temp.
MON. 10:00 AM Flow Switch
MON. 10:00 AM System
Cycling
MON. 10:00 AM Multi-Unit
MON. 10:00 AM Internal
Clock
MON. 10:00 AM AC under-
voltage
MON. 10:00 AM Power Fault
Remote Stop
MON. Anti-Recycle,
20 Min. Left
GOVERNING CONTROL FUNCTION
METHOD OF
DESCRIPTION
RESTART ON
RISE
Autostart Low Water Chilled
(LWT) water
setpoint
Autostart Flow Switch
Autostart A remote com-
mand (computer
relay contact or
manual switch)
Autostart (Optional) Lead-
Lag Sequence
Control
Autostart Internal Clock
Autostart <15% FLA for
25 continuous
seconds
Autostart CM-2 Current
Module or
Solid State
Starter
Energy manage-
ment System
Anti-Recycle
timer
PROGRAMMED
OPERATING
SETPOINTS
POINT
BY OPERATOR
ON
FALL
4°F below 4°F below chilled
chiller water setpoint
water (If set to 40°F
setpoint would be 36°F)
(36°F minimum
Daily Schedule
Programmed to
Shutdown Unit
Will not start
until 30 Min.
timer is timed
START-UP OF PROBABLE CAUSE
SYSTEM AFTER AND SERVICE
SHUTDOWN REQUIRED
Automatic Restart System load is less
when water reaches than minimum
setpoint; if system capacity
is running and set-
point is increased
4°F, system will
continue to run, as
LWT cutout shifts
to a fixed 36°F for
10 minutes.
Automatic Restart Lack of water flow.
when water flow is Check operation of
Restored to close chilled water pump
flow switch.
Automatic Restart Contact-connected to
upon remote the Remote/Local
command. cycling input of the
Digital input board
Automatic Restart Contact-connected to
upon remote the Multi-Unit cycling
command. input of the Digital
input board
Will automatically Pressing Compressor
restart when pro- Start Switch over-
grammed schedule rides the program
permits
Cycling shutdown oc-
curs when motor cur-
rent is >15% FLA for
25 seconds during
chiller operation
Will start automatic- Motor Controller con-
tically following tacts opening and
coastdown closing in less than 3
seconds due to a power
fault condition
Start up by start Remote Stop Contact
signal from remote Closure
start switch
Will restart when Min. Time between
time left = 00 Min. successive compres-
sor starts is 30 min.