252
FORM 160.54-M1
ISSUE DATE: 10/25/2019
SECTION 30 - QUICK START
JCI COMPANY CONFIDENTIAL
JOHNSON CONTROLS
Normal operation turns the oil pump off at the end of
coastdown. When Quick Start is ENABLED the oil
pump shall be kept running through coastdown until 30
seconds after the end of coastdown and into the restart.
If a quick restart does not occur within 30 seconds of
the end of coastdown, the oil pump shall return to stan-
dard control and turn off.
When Quick Start is ENABLED oil pressure pulldown
is in effect (45 psid target) throughout coastdown, 30
seconds after coastdown is complete and 15 seconds
into run if a quick restart is initiated.
The OIL - LOW TEMPERATURE DIFFERENTIAL
cycling shutdown threshold is 30 or 40°F depending
on conditions. When Quick Start is ENABLED this
threshold is reduced to 10°F for 15 minutes after the
last shutdown. This 15 minute time shall begin when
the run signal is DISABLED.
With the Quick Start feature, the Oil Heater is con-
trolled to maintain a minimum oil temperature, ensur-
ing it is warm enough to allow a restart as described
below.
While the oil pump is running, if oil temperature is less
than 100°F, turn the Oil Heater on and if oil tempera-
ture is greater than 105°F, turn the Oil Heater off. Oth-
erwise, do not change existing logic. The Oil Heater
wiring must be changed in order to make this func-
tion work properly. In standard configuration, the Oil
heater does not have AC power available to it (from
TB5-23) when the chiller run signal is enabled. Since
the Oil Heater logic with Quick Start, as described
above, requires the heater to be turned on while the Oil
Pump is running (which is while the chiller run signal
is enabled), the Oil Heater wiring must be changed to
a terminal (TB5-22) that has AC power, while the run
signal is enabled by relocating wire #23 on I/O Board
TB5-23 to TB5-22.
Hot gas Control
When Quick Start is enabled the hot gas output shall be
set to the programmed Maximum Open value during
all of the following conditions:
• During soft shutdown
• During coastdown
• While not running
Hot gas shall return to normal control (closed) when
the run signal is enabled.
ACC Control
When the VSD has reached the VSD Start Frequency,
the ACC speed command shall be ramped towards the
maximum VSD frequency at a rate defined by the fol-
lowing table.
INITIAL RAMP
FREQUENCY INCREASE
RATE
CONDITIONS REQUIRED
0.1Hz / 2 sec
Quick Start Disabled
0.1Hz / 1 sec
Quick Start Enabled and
Motor Current more than
Quick Ramp Disable
0.1Hz / 0.5 sec
Quick Start Enabled and
Motor Current less than
or equal to Quick Ramp
Disable
These rates will be reduced by the present ACC logic
that limits the rate of speed increases when motor cur-
rent is greater than 80% FLA. This initial ramp will
continue until one of the following Quick Ramp Dis-
able conditions are present:
• Motor Current more than 100% FLA
• LCHLT less than Active LCHLT se Quick
Pulldown Setpoint Offset
• Command Frequency equals Maximum VSD Fre-
quency
• Run Time more than Pulldown Override Time
Once one of these conditions is met, ACC control shall
return to standard.
