York ECO2 YPAL 050 - Manual (Page 94)

94 JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
Sequence of Operation
“ B U I L D I N G S TAT I C P R E S S U R E S E N S O R
INSTALLED” – must be turned on using Parameter 85
under the PROGRAM key on the Simplicity Elite control
board or under the EQUIPMENT INSTALLATION tab
in the Simplicity PC software package.
“BUILDING PRESSURE SETPOINT” must be
programmed using Parameter 31 under the PROGRAM
key on the Simplicity Elite control board or under the
ECONOMIZER/EXHAUST tab in the Simplicity PC
software package.
“EXHAUST VFD INSTALLED” must be turned
on using Parameter 45 under the PROGRAM key
on the Simplicity Elite control board or under the
ECONOMIZER/EXHAUST tab in the Simplicity PC
software package.
Sequence of Operation
When the building static pressure is 0.025” WC or more
above the “BUILDING PRESSURE SETPOINT” the
Simplicity Elite control sends a 2 to 10 volt DC signal
to Exhaust Fan VFD, the output is at the “EXD+” and
“EXD-“ terminals at the P14 connector, and enables
the VFD operation through the output at the “EXH”
terminal of the P13 connector. When the exhaust fan
fi rst comes on it will operate at the “Output Frequency
Low Limit” that is programmed into the Exhaust
Van VFD, regardless of the voltage output from the
Simplicity Elite control.
When the building static pressure is 0.025” WC or
more below the “BUILDING PRESSURE SETPOINT”
the Simplicity Elite control lowers the 2 – 10 volt DC
output to the Exhaust Fan VFD. When the output is
equal to or below 2 volts, the Exhaust Fan VFD enable
input is removed.
PRE-OCCUPANCY PURGE
This feature allows the blower to come on and the
economizer damper to open during the unoccupied
period to purge the air within the conditioned space.
In order to use this feature the following parameters
must be programmed:
“PRE-OCCUPANCY PURGE ENABLE” – must be
enabled using the SYSTEM OPTIONS tab in the
Simplicity PC software package.
“PRE-OCCUPANCY PURGE TIME (hours of day)”
– must be programmed using the SYSTEM OPTIONS
tab in the Simplicity PC software package.
“PRE-OCCUPANCY PURGE TIME (minutes of day)”
– must be programmed using the SYSTEM OPTIONS
tab in the Simplicity PC software package.
Criteria for Operation
•
The feature will only work when the internal
scheduling feature is being used to determine
occupied and unoccupied periods.
•
The feature will only work on a day that has a
occupied period scheduled.
Sequence of Operation
•
The programmed “PRE-OCCUPANCY PURGE
TIME” is length of the pre-purge prior to the
start of the occupancy period. For example if
the “PRE-OCCUPANCY PURGE TIME (hours
of day)” is set for 1, the “PRE-OCCUPANCY
PURGE TIME (minutes of day)” is set to 30 and
the occupancy start time is 8:00 AM pre-purge
would start at 6:30 AM and operate until 8:00
AM.
•
While in the pre-purge mode the Simplicity Elite
control will turn on the fan and modulate the
outdoor air damper to 100% as long as the supply
air temperature is between 45.0° F and 90.0° F.
•
If the supply air temperature drops below 45.0° F
the control will modulate the outdoor air damper
closed until the supply air temperature rises above
50.0° F.
•
If the supply air temperature rises above 90.0° F
the control will modulate the outdoor air damper
closed unit the supply air temperature falls below
85.0° F.