Capacity Compressor Cycling Screen; Figure 23 - Capacity Compressor Cycling Screen - York OPTIVIEW YD Series Manual

SECTION 2 – OPTIVIEW CONTROL CENTER

CAPACITY COMPRESSOR CYCLING SCREEN

FIGURE 23 - CAPACITY COMPRESSOR CYCLING SCREEN

This screen allows the user to specify the chiller load
conditions under which the lag compressor is cycled on
and off. Both compressors are not started at the same
time. The lead compressor is started first. If it does not
meet the load requirements as established with the fol-
lowing setpoints, the lag compressor is started. After
the lag compressor is running, it will be shutdown if the
load decreases to the point established by the following
setpoints. Parameters pertinent to chiller loading are
displayed. Also, compressor #1 or #2 can be selected
for lockout.
DISPLAY ONLY
Temperature Differential (Leaving Chilled Liq-
uid Temperature - Setpoint)
Displays the difference between the Leaving Chilled
Liquid Temperature and the Leaving Chilled Liquid
Temperature Setpoint.
Delta T Rate
Displays the rate of change of the Leaving Chilled Liq-
uid Temperature as "X.X ºF/Minute". Value displayed
represents a five-point rolling average obtained as fol-
lows: After the first 3 minutes of chiller run time, the
Leaving Chilled Liquid Temperature is sampled once
70
every minute. The previous reading is subtracted from
the present reading and the last 5 results are averaged
to obtain a five-point rolling average. Displayed as
zero when chiller is not running.
Lead % Full Load Amps
Displays the motor current of the lead compressor as
a percentage of the full load amps of that compressor
motor.
Lead PRV Position
Displays the position of the lead compressor pre-rota-
tion vanes position.
Lead VGD Position
Displays the position of the lead compressor Variable
Geometry Diffuser.
Lead VSD Output Frequency
Displays the value of the lead compressor VSD output
frequency if a VSD is installed.
Lag % Full Load Amps
Displays the motor current of the lag compressor as
a percentage of the full load amps of that compressor
motor.
FORM 160.79-O3
ISSUE DATE: 11/09/2018
LD27862
JOHNSON CONTROLS