44
Y
ORK INTERNA
TIONAL
SECTION 6
T
R
OUBLESHOO
TING
TABLE 1 – CAUSES OF NORMAL AND SAFETY SYSTEM SHUTDOWNS IN ACCORDANCE WITH THE MICROCOMPUTER CONTROL,
CENTER DISPLAY
SHUTDOWN CAUSE
GOVERNING CONTROL FUNCTION
CONTROL CENTER DISPLAY
OPERATING
PROGRAMMED
START-UP OF
PROBABLE CAUSE
DAY OF
TIME OF
CAUSE OF
METHOD OF
DESCRIPTION
POINT
SETPOINTS
SYSTEM AFTER
AND SERVICE
WEEK
DAY
SHUTDOWN
RESTART
ON
ON
BY OPERATOR
SHUTDOWN
REQUIRED
RISE
FALL
MON.
10:00 AM
Low Water
Autostart
Low Water
Chilled
4°F below
4°F below chilled
Automatic Restart
System load is less
Temp.
(LWT)
water
chiller
water setpoint
when water reaches
than minimum
setpoint
water
(If set to 40°F
setpoint; if system
capacity
setpoint
would be 36°F)
is running and set-
(36°F minimum
point is increased
4°F, system will
continue to run, as
LWT cutout shifts
to a fixed 36°F for
10 minutes.
MON.
10:00 AM
Flow Switch
Autostart
Flow Switch
Automatic Restart
Lack of water flow.
when water flow is
Check operation of
Restored to close
chilled water pump
flow switch.
MON.
10:00 AM
System
Autostart
A remote com-
Automatic Restart
Contact-connected to
Cycling
mand (computer
upon remote
the Remote/Local
relay contact or
command.
cycling input of the
manual switch)
Digital input board
MON.
10:00 AM
Multi-Unit
Autostart
(Optional) Lead-
Automatic Restart
Contact-connected to
Lag Sequence
upon remote
the Multi-Unit cycling
Control
command.
input of the Digital
input board
MON.
10:00 AM
Internal
Autostart
Internal Clock
Daily Schedule
Will automatically
Pressing Compressor
Clock
Programmed to
restart when pro-
Start Switch over-
Shutdown Unit
grammed schedule
rides the program
permits
MON.
10:00 AM
AC under-
Autostart
<15% FLA for
Cycling shutdown oc-
voltage
25 continuous
curs when motor cur-
seconds
rent is >15% FLA for
25 seconds during
chiller operation
MON.
10:00 AM
Power Fault
Autostart
CM-2 Current
Will start automatic-
Motor Controller con-
Module or
tically following
tacts opening and
Solid State
coastdown
closing in less than 3
Starter
seconds due to a power
fault condition
Remote Stop
Energy manage-
Start up by start
Remote Stop Contact
ment System
signal from remote
Closure
start switch
MON.
Anti-Recycle,
Anti-Recycle
Will not start
Will restart when
Min. Time between
20 Min. Left
timer
until 30 Min.
time left = 00 Min.
successive compres-
timer is timed
sor starts is 30 min.