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FORM 160.87-OM1
ISSUE DATE: 8/24/2018
FIGURE 50 - QUICK START SCREEN
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 reducing 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, con-
trol returns to normal.
Quick Start feature has two different start modes:
• Quick Restart – When the chiller shuts down, 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, however the vanes will begin to open at the
JOHNSON CONTROLS
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
QUICK START SCREEN
beginning of prelube, instead of waiting until Sys-
tem Run. At the completion of prelube, the VSD
is started and after the VSD achieves its Start Fre-
quency, the speed ramp rate is faster than with
normal control.
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 on the Setpoints
Screen with an ADMIN password by a qualified Ser-
vice Technician. Once enabled, all setpoints and pa-
rameters related to this feature are displayed on this
screen, when logged in at SERVICE access level.
LD14341
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