York ECO2 YPAL 050 - Manual (Page 98)

98 JOHNSON CONTROLS
FORM 100.50-NOM6 (1207)
Sequence of Operation
“Economizer Minimum Position” Alarm
•
The supply air temperature must be above the
“SUPPLY AIR TEMP ALARM SETPOINT FOR
COOLING” set point and the following sequence
of events have occurred:
– All the stages of cooling must have been on
for 10 or more minutes.
– The outdoor air is 20.0° F or more warmer
then the “SUPPLY AIR TEMP ALARM
SETPOINT FOR COOLING” set point.
– The economizer must be open more than
20%.
•
If the above criteria is met:
– The Simplicity Elite control will close the
outdoor damper for ten minutes.
– After ten minutes, the Simplicity Elite control
will read the supply air temperature.
– If the supply air temperature is below the
“SUPPLY AIR TEMP ALARM SETPOINT
FOR COOLING”, the control will keep the
outdoor damper closed and complete the cool-
ing cycle.
∗
The Simplicity Elite control will declare an
“ECONOMIZER MINIMUM POSITION”
alarm and fl ash an Alarm Code 40.
– If the supply air temperature is not below the
“SUPPLY AIR TEMP ALARM SETPOINT
FOR COOLING”.
∗
The Simplicity Elite control will declare a
“SUPPLY AIR TEMP ALARM SETPOINT
FOR COOLING” alarm and flash an
Alarm Code 38.
– After the cooling cycle is completed, the Sim-
plicity Elite control sets the outdoor damper
to its minimum position.
– In order to reset the above alarms power to
the unit must be cycled on and off.
ALARM HISTORY
The last fi ve alarms can be view on the Simplicity Elite
control board as follows. The sequence below gives the
alarms from the most recent to the oldest.
Alarm 1 – The most recent alarm can be viewed
under Parameter 72 using the PROGRAM key on the
Simplicity Elite control board.
Alarm 2 – The next alarm in sequence can be viewed
under Parameter 73 using the PROGRAM key on the
Simplicity Elite control board.
Alarm 3 - The next alarm in sequence can be viewed
under Parameter 74 using the PROGRAM key on the
Simplicity Elite control board.
Alarm 4 - The next alarm in sequence can be viewed
under Parameter 75 using the PROGRAM key on the
Simplicity Elite control board.
Alarm 5 - The next alarm in sequence can be viewed
under Parameter 76 using the PROGRAM key on the
Simplicity Elite control board.
The above alarms can also be viewed using the
ALARMS tab in the Simplicity PC software program.