York YK-EP Operation And Maintenance Manual page 63

Table 48: Programmable
Button Access level
Surge
Service
Sensitivity
Note: *
When an Excess Surge situation is detected, the action depends upon the following:
• If both the Shutdown and Extended Run Setpoints are Disabled, the chiller will continue
to run, displaying the message WARNING – EXCESS SURGE DETECTED. Refer to Hot
Gas Bypass and Variable Speed Drive exceptions. See Shutdown (Enabled/Disabled) and
Extended Run (Enabled/Disabled) in Table 48.
• If the Shutdown Setpoint is Enabled and the Extended Run Setpoint is Disabled, the
chiller will perform a safety shutdown and display Surge Protection – Excess Surge. Refer
to Hot Gas Bypass and Variable Speed Drive exceptions. See Shutdown (Enabled/ Disabled)
and Extended Run (Enabled/Disabled) in Table 48.
• If the Shutdown Setpoint is Disabled and the Extended Run Setpoint is Enabled, the Pre-
Rotation Vanes are driven closed for 10 minutes and WARNING – SURGE PROTECTION
– EXCESS SURGE LIMIT is displayed. When the 10 minutes have elapsed, if the Surge
Window Count is less than or equal to the Count Limit, this message and load inhibit
are automatically cleared. Alternating with this message is WARNING – EXCESS SURGE
DETECTED that continues after the 10 minute period has elapsed until manually cleared
with the WARNING RESET key. Refer to Hot Gas Bypass and Variable Speed Drive
exceptions. See Shutdown (Enabled/Disabled) and Extended Run (Enabled/Disabled) in Table
48.
• If both the Shutdown and Extended Run Setpoint are Enabled, the 10 minute Extended
Run mode is invoked as described above. However, if the Surge Window Count exceeds
the Count Limit at the completion of the 10 minute Extended Run period, a safety
shutdown is performed and Surge Protection – Excess Surge is displayed. Refer to Hot
Gas Bypass and Variable Speed Drive exceptions. See Shutdown (Enabled/Disabled) and
Extended Run (Enabled/Disabled) in Table 48.
Table 49: Navigation
Button Access level
Home View
Compressor View
YK-EP Style B Centrifugal Chiller
Description
Allows the user to define the surge detection sensitivity of the
Surge Protection feature. The Surge Sensitivity Setpoint on the
ACC DETAILS Screen sets the sensitivity of the ACC Surge Detection
feature that is employed for ACC Surge Detection. Selectable over
the range of 0.3 to 1.3; default 0.3. The smaller the number, the
greater the sensitivity.
Description
Returns user to HOME Screen.
Returns user to COMPRESSOR Screen.
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