Quick Start Screen - York YK Style H Operation Manual

Quick start screen

Figure 66: Quick start screen
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, 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, however 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.
In order to use this feature, the chiller must be equipped with a Variable Speed Drive 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 OptiView Control Center – Service
Instructions (Form 160.76-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 OptiView Control Center – Service Instructions (Form 160.76-M1) for
complete explanation of this feature.
Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center 127