York YK Style H Operation Manual page 128

SECTION 2 - OPTIVIEW CONTROL CENTER INTRODUCTION
DISPLAY ONLY
Leaving Chilled Liquid Temperature
Displays the temperature of the liquid as it leaves the
evaporator.
Leaving Chilled Active Setpoint
Displays the setpoint to which the Leaving Chilled
Liquid is being controlled.
Quick Pulldown in Effect (LED)
Illuminates while a Quick Pulldown is in effect. This is
in effect from a start initiate until the Quick Pulldown
Setpoint Offset has been reached or the Pulldown
Override Time has elapsed, whichever occurs first.
For fields requiring access level of SER-
VICE. Service Technicians refer to the
OptiView Control Center - Service Instruc-
tions (Form 160.76-M1) for operation
instructions and explanation of all pro-
grammable setpoints and displayed values.
PROGRAMMABLE
Change Setpoints
Access Level Required: SERVICE
Used to enter the following setpoints. Pressing this key
places a green selection box around the first change-
able setpoint. Use the ▲ and ▼ keys to place the selec-
tion box around the desired setpoint. With the setpoint
selected, press the ENTER () key. A dialog box ap-
pears with the range of settings.
Quick Start Mode
Access Level Required: ADMIN
(Enabled, Disabled; default Disabled) This setpoint
is used to Enable and Disable the Quick Start feature.
It can only be Enabled when the Motor Drive Type
Setpoint is set to VSD or MVVSD. If Heat Pump Duty
is enabled, the Quick Start feature is only available
when the Heat Pump Operational mode setpoint is set
to Cooling.
The default is Disabled. Quick Start can only be en-
abled using an ADMIN password. When logged in at
ADMIN access level, a QUICK START key will ap-
pear on the SETPOINTS Screen. Pressing this key
will navigate to the QUICK START Screen where this
setpoint is used to enable/disable the feature.
128
Quick Start can be Disabled when logged in at SER-
VICE access level. However, once Disabled, it requires
an ADMIN password to enable it again, as explained
previously. Quick Start mode will be automatically
disabled when any of the following occur: The Motor
Drive Type is changed to something other than VSD
or MVVSD, or the Motor Communications Protocol is
changed to YORK, or the Heat Pump Duty (if enabled)
Operational Setpoint is set to Heating mode.
Quick Pulldown Setpoint Offset
Access Level Required: SERVICE
(0°F to 10°F; default 5°F) This setpoint sets the Leav-
ing Chilled Liquid Temperature at which the control
transitions from Quick Start mode to normal opera-
tion. It is entered in the form of an offset above the
active Leaving Chilled Liquid Temperature (LCHLT)
Setpoint. Once the Leaving Chilled Liquid Tempera-
ture falls below the Active LCHLT Setpoint plus Quick
Pulldown Setpoint Offset, PRV (Quick Restart) and
speed control (Quick Restart and Quick Normal Start)
revert to normal automatic control. Lower values of
this offset result in faster pulldown times but can result
in overshoot of the LCHLT Setpoint. Setting the value
to its minimum of 0 results in the fastest pulldown time
but nearly always results in setpoint overshoot. De-
pending upon how close the Low Chilled Liquid Tem-
perature shutdown threshold is to the LCHLT Setpoint,
this could result in a LOW CHILLED LIQUID TEM-
PERATURE cycling shutdown.
The Leaving Chilled Liquid Temperature and setpoint
is shown on the QUICK START Screen for reference.
This setpoint sets one of the two setpoints that deter-
mine when the control transitions from Quick Start
mode to normal operation. The other is the Pulldown
Override Time below.
Pulldown Override Time
Access Level Required: SERVICE
(0 min to 15 min; default 10 min) This setpoint is the
length of time the PRV is held open (Quick Restart) and
the ACC speed (Quick Restart and Quick Normal Start)
is increased on startup if the Quick Pulldown Setpoint
Offset is not reached. This could be due to hitting cur-
rent limit during the pulldown. If the Quick Pulldown
Setpoint Offset is not reached in the Pulldown Override
Time, PRV and ACC speed control will revert back to
normal automatic control.
FORM 160.76-O2
issue date: 6/15/2015
JOHNsON CONtROLs