York YK Style H Operation Manual page 65

Table 48: Programmable
V09 software
Button
and earlier
Shutdown
(Enabled/ Operator
Disabled)
Extended Run
(Enabled/ Operator
Disabled)
Count Window Operator
Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center
V10 and later
with YORK
Description
Chiller Access
Manager
Allows the user to select whether the chiller will shutdown or continue to
run when an Excess Surge situation has been detected.
If this setpoint is set to Enabled and the Extended Run Setpoint is
Disabled, a safety shutdown is performed when the Surge Window Count
exceeds the Count Limit Setpoint.
If this setpoint is Enabled and the Extended Run Setpoint is Enabled, a
safety shutdown is performed if the Surge Window Count exceeds the
Count Limit Setpoint at the completion of the 10 minute Extended Run
period.
Standard
Surge Protection – Excess Surge is displayed with either shutdown.
If this setpoint is Disabled, see operation under
• If equipped with a compressor Variable Speed Drive or MVVSD, the
VSD output frequency must be at maximum before the Shutdown
feature is implemented or Surge Warning messages are displayed.
• If equipped with a VSD or MVVSD and Hot Gas Bypass (Enabled), the
VSD output frequency must be at maximum and the Hot Gas Valve
must be at 100% before the Shutdown feature is implemented or
Surge warning messages are displayed.
Allows you to select the surge correction/avoidance Extended Run mode.
This is implemented when an Excess Surge situation is detected as
follows:
Anytime the Surge Window Count exceeds the Count Limit, the Pre-
rotation Vanes are driven closed for the next 10 minutes. While this load
inhibit is in effect, WARNING – SURGE PROTECTION – EXCESS SURGE
LIMIT is displayed. When 10 minutes have elapsed, the warning message
and load inhibit are automatically cleared, provided the Surge Window
Count is less than or equal to the Count Limit. If the Shutdown Setpoint
Standard is Enabled, and the Surge Window Count exceeds the Count Limit at the
completion of this period, a safety shutdown is performed and Surge
Protection – Excess Surge is displayed.
If the Hot Gas Bypass control is Enabled, the Hot Gas Bypass Valve
position must be 100% before the Extended Run mode is implemented.
If the chiller is equipped with a Compressor Motor Variable Speed Drive,
output frequency must be at full speed (50 Hz/60 Hz) before the Extended
Run mode is implemented. If the chiller is equipped with both Hot
Gas Bypass and Compressor Motor Variable Speed Drive, both of the
conditions must be met before Extended Run is implemented.
Allows the user to define the period of time (1 to 5 minutes; default 3; in
which the number of surge events (Surge Window Count) are compared
Standard
to the maximum allowed (Count Limit), for the purpose of detecting an
Excess Surge situation.
Count Limit.
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