York YK Style H Operation Manual page 67

FORM 160.76-O2
issue date: 6/15/2015
Allows the user to define the maximum number of surge
events (4 to 20; default 15; that can occur within a de-
fined period of time before an Excess Surge situation is
detected. If the Surge Window Count exceeds the Count
Limit, an Excess Surge situation has occurred.
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 Shut-
down (Enabled/Disabled) on Page 66 and Ex-
tended Run (Enabled/Disabled) on Page 66.
• If the Shutdown Setpoint is Enabled and the Extend-
ed 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) on Page 66 and Extended Run (En-
abled/Disabled) on Page 66.
• If the Shutdown Setpoint is Disabled and the Ex-
tended Run Setpoint is Enabled, the Pre-rota-
tion Vanes are driven closed for 10 minutes and
WARNING – SURGE PROTECTION – EXCESS
SURGE LIMIT is displayed. When the 10 min-
utes have elapsed, if the Surge Window Count is
less than or equal to the Count Limit, this message
and load inhibit are automatically cleared. Alternat-
ing 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) on Page 66 and
Extended Run (Enabled/Disabled) on Page 66.
• If both the Shutdown and Extended Run Setpoint
are Enabled, the 10 minute Extended Run mode
JOHNSON CONTROLS
SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
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 excep-
tions. See Shutdown (Enabled/Disabled) on Page
66 and Extended Run (Enabled/Disabled) on
Page 66.
Surge Sensitivity
Access Level Required: SERVICE
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 sensi-
tivity of the ACC Surge Detection feature that is em-
ployed for ACC Surge Detection when configured in
MODBUS serial communications protocol. Selectable
over the range of 0.3 to 1.3; default 0.3. The smaller the
number, the greater the sensitivity.
Clear Surge Count
Access Level Required: ADMIN
Allows user to set the Total Surge Count to zero.
NAVIGATION
Home
Access Level Required: VIEW
Returns user to HOME Screen.
Compressor
Access Level Required: VIEW
Returns user to COMPRESSOR Screen.
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