FORM 160.54-O1
111
JOHNSON CONTROLS
2
PROGRAMMABLE
Change Setpoints
Access Level Required: SERVICE or higher
Used to enter the following setpoints. Pressing this key
places a green selection box around the rst changeable
setpoint. Use the ▲ and ▼ keys to place the selection box
around the desired setpoint. With the setpoint selected,
press the ENTER (√) key. A dialog box appears 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 and the Motor Communications Protocol
is set to Modbus. Or, the Motor Drive Type Setpoint is
set to MVVSD. The default is DISABLED. Quick Start
can only be enabled using an ADMIN password. When
logged in at ADMIN access level, a QUICK START key
will appear on the SETPOINTS Screen. Pressing this
key will navigate to the QUICK START Screen where
this setpoint is used to enable/disable the feature.
Quick Start can be Disabled when logged in at Service
access level. However, once Disabled, it requires an
ADMIN password to enable it again, as explained above.
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.
Quick Pulldown Setpoint Offset
Access Level Required: SERVICE
(0ºF to 10ºF; default 5ºF) - This setpoint sets the Leav-
ing Chilled Liquid Temperature at which the control
transitions from Quick Start mode to normal operation.
It is entered in the form of an offset above the active
Leaving Chilled Liquid Temperature (LCHLT) Setpoint.
Once the leaving chilled liquid temperature falls below
the Active LCHLT Setpoint + Quick Pulldown Setpoint
Offset, PRV (Quick Restart) and speed control (Quick
Restart and Quick Normal Start) revert to normal auto-
matic 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. Depending upon how close the Low
Chilled Liquid Temperature shutdown threshold is to
the LCHLT setpoint, this could result in a Low Chilled
Liquid Temperature 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 determine
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.
VSD Start Frequency
Access Level Required: SERVICE
(60Hz units with quick start enabled = 30Hz to 45Hz;
default 45Hz)(50Hz = 25Hz to 37.5Hz; default 37.5Hz)
- This setpoint is the same as shown on the ACC Details
Screen. It can be programmed on either the ACC Screen
or the Quick Start Screen. It sets the VSD start frequency
from which the speed will ramp from.
Mapping Enable
Access Level Required: SERVICE
(0.5ºF to 4.0ºF; default 1.0ºF) - This is the same setpoint
as shown on the ACC Details Screen. It can be pro-
grammed on either the ACC Screen or the Quick Start
Screen.It sets the Delta T needed to be met to enable surge
mapping and speed reduction initially on startup.
Quick Ramp Current Threshold
Access Level Required: SERVICE
(20% to 80% FLA; default 50%) - This setpoint sets
the motor current threshold where the VSD speed com-
mand ramp rate changes. At or below this threshold the
speed command ramp is 4X of standard control. Over
this threshold, the ramp rate is 2X of standard control
until it hits the standard current limiting over 80% FLA.
Higher current thresholds can result in faster pulldown
times. However, setting this value too high can result in
slower pulldown times due to hitting the current limit
sooner on pulldown.
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