Surge protection screen
Figure 40: Surge protection screen
This screen displays a cutaway view of the chiller compressor and all parameters relating to the
Surge Protection feature. All setpoints relating to this screen are maintained on this screen.
The Surge Protection feature detects surge events and provides a running count of the surges
detected over the lifetime of the chiller. It allows the user to define how many surges are excessive
and how the control will react to an excess surge condition. When excess surging is detected, it
can be configured to shutdown the chiller, or initiate a surge avoidance mode while allowing it to
continue to run or simply display a warning message. The sensitivity of this surge detection is set
by the Sensitivity Setpoint on this screen. The surges detected by this feature are also used for the
Hot Gas Bypass feature. See
The parameters displayed on this screen vary according to the software version and the motor
starter type as noted below.
Table 47: Display only fields
Field/LED name
Description
Delta P/P
A parameter that represents the system differential or Head Pressure. It is calculated
as (condenser pressure – evaporator pressure) / evaporator pressure.
Surge Avoidance Surge Detected
(LED)
Illuminates momentarily when a surge is detected by the Surge Protection feature. If
equipped with a VSD or MV VSD these are only the surges detected while the drive is
running at maximum frequency.
ACC Surge Detected (LED)
Only displayed if equipped with a VSD or MV VSD. Illuminates momentarily when a
surge is detected by the ACC function in the Microboard, while the drive is running at
less than maximum frequency.
Surge Window Time
When the chiller enters run mode, this value counts up to the time programmed as the
Count Window Setpoint. When it reaches the Count Window minutes, the number of
surge events in the oldest minute is discarded and the number of surge events in the
most recent minute is added, thus providing a rolling count of the total surge events
that have occurred in the last Count Window minutes. This value is reset when the
chiller shuts down.
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Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center
