Johnson Controls YORK YK MaxE, Operation Manual

Page: 110 / 184

JOHNSON CONTROLS
110
FORM 160.54-O1
optiView Control Center
qUiCK start sCreeN
(Software version C.OPT.01.21.307 and later)
oVerVieW
The Quick Start feature is useful in data center and
process control applications where it is desirable to re-
establish cooling as fast as possible after a shutdown or
power failure. This feature, when enabled, allows quicker
starts and restarts than normal control. It does this by re-
ducing the time cycle for chiller restart and once running,
loading the chiller as fast as possible. After the chiller is
running and has met a specified setpoint or a specified
period of time has elapsed, control returns to normal.
Quick Start feature has two different start modes:
• Quick Restart – When a chiller shutsdown, if certain
conditions are met at the completion of Coastdown
(and within 30 seconds thereafter), the VSD is started
immediately with no Prelube. The vanes are given
a constant open pulse and after the VSD achieves
its start frequency, the speed ramp rate is faster than
with normal control.
• Quick Normal Start – If the conditions for a Quick
Restart are not met, the next time the chiller is started,
it has a prelube period just like a normal start, how-
ever the vanes will begin to open at the beginning
of Prelube, instead of waiting until System Run. At
the completion of Prelube, the VSD is started and
after the VSD achieves its Start Frequency, the speed
ramp rate is faster than with normal control.
LD14341
fig. 27a
In order to use this feature, the chiller must be equipped
with a Variable Speed Drive in Modbus Protocol Con-
figuration or a Medium Voltage Variable Speed Drive.
The low inrush current of a VSD allows more starts per
hour and allows the chiller to start with a more open vane
position. It must be enabled with an ADMIN password
by a qualified service technician using the procedure in
Service Manual 160.54-M1. Once enabled, all setpoints
and parameters related to this feature are displayed on
this screen, when logged in at Service access level.
Service technicians refer to Service manual 160.54-M1
for complete explanation of this feature.
dispLaY oNLY
Leaving Chilled Liquid Temperature
Displays the temperature of the liquid as it leaves the
evaporator.
Leaving Chilled Active Setpoint
Displays the setpoint to which the Leaving Chilled Liquid
is being controlled.
Quick Pulldown in Effect (LED)
Illuminates while a Quick Pulldown is in effect. This is
in effect from a start initiate until the Quick Pulldown
Setpoint Offset has been reached or the Pulldown Over-
ride Time has elapsed, whichever occurs first.