York YK-EP B Operation & Maintenance Manual page 54

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
Surge Window Count
Displays the number of surge events that have occurred
in the last 1 to 5 minutes as programmed with the Count
Window Setpoint. If the chiller has been running for
less than the Count Window minutes, it is the number
of surge events that have occurred within the last num-
ber of minutes displayed as the Surge Window Time.
The count is cleared when the chiller shuts down.
Surge Avoidance Surge Detected (LED)
Illuminates momentarily when a surge is detected by
the Surge Protection feature. If equipped with a VSD
or MVVSD these are only the surges detected while
the drive is running at maximum frequency.
Surge Avoidance Surge Count
This is the total number of surges accumulated by the
Surge Protection feature. If equipped with a VSD or
MVVSD, it is only the surges detected while the drive
is running at maximum frequency.
Extended Run Time Remaining
Displays the time remaining in the 10-minute Extended
Run period. During this period, the Pre-Rotation Vanes
are driven closed and WARNING – SURGE PROTEC-
TION – EXCESS SURGE LIMIT is displayed. Refer
to operation under Count Limit on Page 55.
PROGRAMMABLE
Shutdown (Enabled/Disabled)
Access Level Required: OPERATOR
Allows the user to select whether the chiller will shut-
down or continue to run when an Excess Surge situa-
tion has been detected.
If this setpoint is 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.
Surge Protection – Excess Surge is displayed with ei-
ther shutdown.
54
If this setpoint is Disabled, refer to operation under
Count Limit on Page 55.
• If equipped with a compressor Variable Speed
Drive (VSD), the VSD output frequency must
be at maximum before the Shutdown feature is
implemented or Surge Warning messages are dis-
played.
• If equipped with a VSD 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.
Extended Run (Enabled/Disabled)
Access Level Required: OPERATOR
Allows the user to select the surge correction/avoid-
ance Extended Run mode. This will be 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 auto-
matically cleared, provided the Surge Window Count is
less than or equal to the Count Limit. If the Shutdown
Setpoint is Enabled, and the Surge Window Count ex-
ceeds 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 Extend-
ed Run mode is implemented. If the chiller is equipped
with a Compressor Motor Variable Speed Drive, output
frequency must be at full speed (50Hz/60Hz) before
the Extended Run mode is implemented. If the chiller
is equipped with both Hot Gas Bypass and Compres-
sor Motor Variable Speed Drive, both of the conditions
must be met before Extended Run is implemented.
Count Window
Access Level Required: OPERATOR
Allows the user to define the period of time (1 to 5 min-
utes; default 3) in which the number of surge events
(Surge Window Count) are compared to the maximum
allowed (Count Limit), for the purpose of detecting an
Excess Surge situation.
FORM 160.87-OM1
ISSUE DATE: 8/24/2018
JOHNSON CONTROLS