York YST User Manual

JOHNSON CONTROLS
139
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
FORM 160.67-O1
ISSUE DATE: 4/1/2015
2
failure) or Safety (manual restart after power failure)
shutdown, depending upon Control Center configuration.
It indicates a cycling shutdown when displayed in
orange characters; Safety shutdown when displayed
in red characters. If configured for auto-restart, the
chiller start sequence will be automatically initiated 35
seconds after the chiller has coasted to a complete stop.
If the power failure duration was less than 6 minutes
when power is restored, a complete postlube sequence
will be performed. The Control Center is configured for
auto-restart or manual restart after power failure by a
qualified Service Technician following instructions in
YORK Service Manual 160.67-M3.
“System Cycling – Contacts Open”
The System Cycling contacts connected to I/O Board
TB4-13, have opened to initiate a cycling shutdown. If
the chiller is running when this occurs, a soft shutdown
sequence is initiated. The chiller will automatically
restart when the contacts close 35 seconds after the
drive train has coasted to a complete stop.
“ Compr Oil – Low Temperature Differential”
The chiller is prevented from starting because for one
of the following reasons. The chiller will automatically
restart when the conditions have been satisfied.
The chiller has been shut down for <30 minutes and the
oil temperature minus the condenser saturation temper-
ature is <30°F.
-OR-
The chiller has been shut down for > 30 minutes and
the oil temperature minus the condenser saturation
temperature is < 40°F.
-OR-
Following a Power failure, upon restoration of power,
the oil temperature minus the condenser saturation
temperature is < 40°F. This safety is enabled when the
chilller is stopped and during the first 10 seconds of
prelube.
“Compr Oil – Low Temperature”
The oil temperature has decreased to <55°F. The
chiller will automatically restart when the temperature
increases to > 55.0°F and is greater than the Condenser
Saturated temperature by 30 or 40°F, as described
above in the COMPR OIL – LOW TEMPERATURE
DIFFERENTIAL message description.
“ Compr Oil – Variable Speed Pump – Drive
Contacts Open”
The Oil Pump Variable Speed Drive has shut down
the chiller by opening its status contacts connected to
the I/O Board TB3-70. The Drive initiates a shutdown
anytime its internal protection circuits will not permit
the Drive to run. The contacts remain open until its
internal protection circuits are satisfied it is safe to
operate. Some Drive initiated shutdowns require AC
power to be cycled to clear the fault. Refer to YORK
Form 160.67-M3. The chiller will automatically restart
when the contacts close.
“ Leaving Chilled Liquid – Low Temperature”
The Leaving Chilled Liquid Temperature has
decreased to the programmed Shutdown Temperature
Setpoint. If the chiller is running when this occurs, a
soft shutdown sequence is initiated. The chiller will
automatically restart when the temperature increases
to the programmed Restart Temperature Setpoint 35
seconds after the drive train has coasted to a complete
stop.
“ Leaving Chilled Liquid – Flow Switch Open”
The Chilled Liquid Flow Switch has remained open for
2 continuous seconds while the chiller was running or
failed to close during the Start Sequence. This check
is bypassed for a programmable delay after the chilled
liquid pump start contacts are closed. These contacts
are closed after the turbine slow roll warm-up has been
completed and the ramp up to rated speed has been
initiated. The chiller will automatically restart when
the flow switch closes.
“Condenser – Flow Switch Open”
The Condenser water flow switch has remained open
for 2 continuous seconds while the chiller was running
or failed to close during the start sequence. This check
is bypassed for 45 seconds after the condenser liquid
pump start contacts have been closed and the message
"START SEQUENCE INITIATED" is displayed. The
chiller will automatically restart when the flow switch
closes.
“ Expansion I/O – Serial Communications”
Serial communications between the Microboard and
the Frick Analog I/O Board has been interrupted for at
least 20 seconds.

York YST Specifications

General

Brand	York
Model	YST
Category	Chiller
Language	English