JOHNSON CONTROLS
128
FORM 145.05-NOM7
ISSUE DATE: 10/31/2019
SECTION 5 ā SEQUENCE OF OPERATION
Required Program Values
⢠PROGRAM key, ECONOMIZER subsection:
āFLUSH CYCLEā must be set to ENABLE
⢠SETPOINTS key, ECONOMIZER subsec-
tion: āFLUSH DELAY TIMEā must be set for
the amount of delay from the time the āFLUSH
CYCLEā is activated until the sequence begins
(default is 0 minutes)
⢠OPTIONS key, ECONOMIZER subsection:
āECONOMIZER INSTALLEDā must be set to
WATERSIDE
Sequence of Operation - Scheduled On/
Off Operation
The following criteria must be met before the control-
ler initiates a Flush Cycle:
⢠āFLUSH CYCLEā is ENABLED
⢠āECONOMIZER INSTALLEDā is set to WA-
TERSIDE
The following must have happened or is in present
state:
⢠Time is between 7:00 PM and 11:59 PM (19:00
and 23:59); this is usually because these are the
most common times when units are UNOCCU-
PIED,
And
⢠Unit is in an UNOCCUPIED mode of operation,
And
⢠No compressors have been ON in the past 5 min-
utes,
And
⢠18 hours has elapsed since the last Flush Cycle
Upon initiation of the Flush Cycle, the controller com-
pletes the following:
⢠Starts a countdown timer to countdown the
time indicated by the āFLUSH DELAY TIMEā
setpoint. Wait until the timer expires.
⢠Turns the āPUMP STARTā BO to ON
⢠Changes the āCURRENT OPER MODEā to
āFLUSHING ECONO COILā
⢠Drives the āCOND WATER VALVEā to 0% (10
VOLTS)
⢠Drives the āECONOMIZER WATER VALVEā to
100% (10 VOLTS)
⢠Waits 3 minutes
⢠Drives the āCOND WATER VALVEā to "COND
VALVE MIN POS"
⢠Drives the āECONOMIZER WATER VALVEā to
āWATER ECONO MIN POSITIONā
⢠Waits 1 minute
⢠Turns the āPUMP STARTā DO to OFF
Changes āCURRENT OPER MODEā back to previous
mode and resume normal operation.
Sequence of Operation - Scheduled 24/7
Operation
The following criteria must be met before the control-
ler initiates a Flush Cycle:
⢠āFLUSH CYCLEā is ENABLED
⢠āECONOMIZER INSTALLEDā is set to WA-
TERSIDE
⢠Time is 11:59 PM (23:59),
And
No compressors have been ON for the past 5 min-
utes,
And
18 hours has elapsed since the last Flush Cycle
Upon initiation of the Flush Cycle, the controller com-
pletes the following:
⢠Turn the āPUMP STARTā BO to ON
⢠Change the āCURRENT OPER MODEā to
āFLUSHING ECONO COIL
⢠Drive the āCOND WATER VALVEā to 0% (10
VOLTS)
⢠Drive the āECONOMIZER WATER VALVEā to
100% (10 VOLTS)
⢠Wait 3 minutes
⢠Drive the āCOND WATER VALVEā to āCOND
VALVE MIN POSā
⢠Drive the āECONOMIZER WATER VALVEā to
āWATER ECONO MIN POSITIONā