York YPAL 060 User Manual

Page of 168
95
JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
5
ENERGY RECOVERY VENTILATOR
If the unit has an Energy Recovery Ventilator installed 
the exhaust fan needs to operate any time the supply fan 
is energized.  This feature can be programmed to only 
occur in the occupied mode or in both the occupied and 
unoccupied mode.
The following parameters must be programmed to use 
this feature:
“ERV ENABLED” – must be enabled using the 
ECONOMIZER/EXHAUST tab of the Simplicity PC 
software package.
If you want this feature to operate in the unoccupied 
mode the following parameter must be enabled.
“ERV UNOCCUPIED FAN ENABLED”- must be 
enabled using the ECONOMIZER/EXHAUST tab of 
the Simplicity PC software package.
Sequence of Operation
In the occupied mode, anytime the supply fan is 
energized the exhaust fan will also be turned on.
If “ERV UNOCCUPIED FAN ENABLED” is enabled 
the exhaust fan will operate in either the occupied or 
unoccupied mode when the supply fan is energized.
If the unit has a Exhaust Fan VFD, the output voltage 
to the Exhaust Fan VFD will be the same as the voltage 
output to the supply fan VFD.
LOW VOLTAGE PROTECTION
The Simplicity Elite control monitors the 24 VAC 
low voltage level.  Before the Simplicity Elite control 
energizes a binary output to a contactor, it checks this 
voltage level.  If the voltage is equal to or less than 
19.2 volts the control will not energize the output and 
will fl ash an Alarm Code 35. If the voltage rises above 
19.2 volts the control will close the output and resume 
normal operation.
If the voltage drops below 16 volts with binary outputs 
already energized, the control will open all the binary 
outputs to the contactors and fl ash an Alarm Code 35.  
If the voltage rises above 19.2 volts the Simplicity Elite 
control will resume normal operation.
OUTDOOR AIR HEATING LOCKOUT
This feature prevents the Simplicity Elite control 
from operating in the heating mode when the outdoor 
temperature is above this set point.
The set point for this feature is programmed through 
the following parameter:
“OUTDOOR AIR TEMP HEATING LOCKOUT” – is 
programmed using the HEATING SETUP tab in the 
Simplicity PC software package.
HOT GAS BYPASS
Hot gas by pass is used to inject discharge gas into the 
expansion valve distributor to artifi cially place a load on 
the evaporator coil under a light load condition.  This is 
done to raise the suction pressure to keep the saturation 
temperature of the refrigerant high enough to prevent 
icing of the coil.  An auxiliary contact on the condenser 
fan, 7M- contactor, energizes the hot gas bypass valve 
whenever the contactor is energized.  The hot gas valve 
monitors the suction pressure and will modulate to keep 
the suction pressure above 55 PSIG.
All VAV units have a hot gas valve installed in the 
number 1 compressor system.   Hot gas is optional 
on CV units. If the lead/lag option is enabled the 
Simplicity Elite control needs to know the hot gas 
option is installed.  This is done through the following 
programming parameter.
“HOT GAS BY PASS PRESENT ON COMPRESSOR # 
1”
 - must be turned on using Parameter 79 under the 
PROGRAM key on the Simplicity Elite control board 
or under the COOLING SETUP tab of the Simplicity 
PC software.
SPACE TEMPERATURE ALARM
When this feature is enabled, the Simplicity Elite 
control monitors the space temperature.  When the 
space temperature continues to trend above or below 
the programmed set point and the programmed time 
has expired, the Simplicity Elite control will declare a 
Space Temperature Alarm.