Surge Protection Screen; Figure 21 - Surge Protection Screen - York YK Style H Operation Manual

FORM 160.76-O2
issue date: 6/15/2015

FIGURE 21 - SURGE PROTECTION SCREEN

OVERVIEW
This screen displays a cutaway view of the chiller com-
pressor and all parameters relating to the Surge Pro-
tection 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 warn-
ing 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 (Refer to Hot Gas Bypass Screen
on Page 63).
The parameters displayed on this screen vary accord-
ing to the software version and the motor starter type as
noted below.
JOHNSON CONTROLS

SURGE PROTECTION SCREEN

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
DISPLAY ONLY
Delta P/P
A parameter that represents the system differential or
Head Pressure. It is calculated as (condenser pressure
– evaporator pressure) / evaporator pressure.
Surge Window Time
When the chiller enters run mode, this value counts
up to the time programmed as the Count Window Set-
point. When it reaches the Count Window minutes, the
number of surge events in the oldest minute is discard-
ed 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.
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.
LD13827
65
2