JOHNSON CONTROLS
65
SECTION 2 – OPTIVIEW CONTROL CENTER
FORM 160.69-O1
ISSUE DATE: 9/30/2012
2
Surge Detected
(LED)
Illuminates for 5 seconds each time a surge is detected.
Total Surge Count
Displays the total number of surge events detected over
the lifetime of the unit (up to a maximum of 65535).
Extended Run Time Remaining
Displays the time remaining in the 10-minute “EX-
TENDED RUN” period. During this period, the Pre-
rotation vanes are driven closed and “Warning – Surge
Protection – Excess Surge Limit” is displayed. Refer to
operation under “Count Limit” below.
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 Ex-
tended Run period.
“Surge Protection – Excess Surge” is displayed with
either shutdown.
If this setpoint is Disabled, refer to operation under
“Count Limit” below.
Extended Run (Enabled/Disabled)
Access Level Required:
OPERATOR
Allows the user to select the surge correction/avoid-
ance EXTENDED RUN mode. This will be imple-
mented when an Excess surge situation is detected as
follows: Anytime the SURGE WINDOW COUNT ex-
ceeds 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 – Ex-
cess Surge Limit’ is displayed. When 10 minutes have
elapsed, the warning message and load inhibit are au-
tomatically 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 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 Ex-
tended Run mode is implemented.
Count Window
Access Level Required:
OPERATOR
Allows the user to define the period of time (1 to 5
minutes; default 5) in which the number of surge
events (SURGE WINDOW COUNT) are compared to
the maximum allowed (COUNT LIMIT), for the pur-
pose of detecting an excess surge situation.
Count Limit
Access Level Required:
OPERATOR
Allows the user to define the maximum number of
surge events (4 to 20; default 4) that can occur within
a defined period of time before an Excess Surge situ-
ation 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”.
• If the SHUTDOWN setpoint is Enabled and the
EXTENDED RUN setpoint is Disabled, the chill-
er will perform a safety shutdown and display
“Surge Protection – Excess Surge”.
• 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 mes-
sage and load inhibit are automatically cleared.
Alternating with this message is “Warning – Ex-
cess Surge Detected” that continues after the 10
minute period has elapsed until manually cleared
with the Warning Reset key. See Hot Gas Bypass
exception above.