Table of Contents
Advertisement
Unit Controls
U N I T
L O W
A M B I E N T
The Low Ambient Temp Cutout is a safety shutdown
designed to protect the chiller from operating in a low
ambient condition. If the outdoor ambient temperature
falls below the programmable cutout, the chiller will shut
down. Restart can occur when temperature rises 2°F
above the cutoff.
U N I T
F A U L T :
L O W
L I Q U I D
The Low Leaving Chilled Liquid Temp Cutout protects
the chiller form an evaporator freeze-up should the
chilled liquid temperature drop below the freeze point.
This situation could occur under low flow conditions or
if the micro panel setpoint values are improperly pro-
grammed. Anytime the leaving chilled liquid tempera-
ture (water or glycol) drops below the cutout point, the
chiller will shutdown. Restart can occur when chilled
liquid temperature rises 2°F above the cutout.
U N I T
1 1 5 V A C
U N D E R
The Under Voltage Safety assures that the system is
not operated at voltages where malfunction of the mi-
croprocessor could result in system damage. When the
115VAC to the micropanel drops below a certain level,
a unit fault is initiated to safely shut down the unit. Re-
start is allowed after the unit is fully powered again and
the anti-recycle timers have finished counting down.
58
F A U L T :
T E M P
T E M P
F A U L T :
V O L T A G E
UNIT WARNING
The following message is not a unit safety and will not
be logged to the history buffer. It is a unit warning and
will not auto-restart. Operator intervention is required to
allow a re-start of the chiller.
! !
L O W
B A T T E R Y
C H E C K
P R O G / S E T P / O P T N
The Low Battery Warning can only occur at unit power-
up. On micropanel power-up, the RTC battery is
checked. If a low battery is found, all programmed
setpoints, program values, options, time, schedule, and
history buffers will be lost. These values will all be reset
to their default values which may not be the desired op-
erating values. Once a faulty battery is detected, the unit
will be prevented from running until the PROGRAM key
is pressed. Once PROGRAM is pressed the anti-recycle
timers will be set to the programmed anti-recycle time to
allow the operator time to check setpoints, program val-
ues, and options.
If a low battery is detected, it should be replaced as
soon as possible. The programmed values will all be
lost and the unit will be prevented from running on the
next power interruption. The RTC/battery is located at
U17 on the microboard.
! !
YORK INTERNATIONAL
Advertisement
Table of Contents
