JOHNSON CONTROLS
52
FORM 155.21-O1 (615)
OptiView Control Center
Manual Dilution Cycle is in progress
A dilution cycle was initiated manually in SERVICE
access and is in progress. It lasts 6 minutes or until
terminated manually.
Manual Operation Control in effect
The Control Valve is in Manual operation, in SERVICE
access. The valve may be in "LOAD", "UNLOAD", or
"HOLD" command.
A limited dilution cycle starts only the solution pump,
and it can last up to 4 hours. If the fault condition clears,
the control reverts to normal dilution.
Primary Limited ADC in progress -
Load set to 50%
Applicable only to units equipped with buffalo
pumps.
The unit is running and performing a “Primary Limited
Automatic Decrystallization Cycle”. This variation of
the standard Automatic Decrystallization Cycle (ADC)
is performed if the refrigerant pump is not running when
a standard ADC is initiated or is turned-off during a
standard ADC.
Limited ADC have two phases: Primary and Secondary
(see below). The Primary Limited ADC is the same as
Standard ADC except it is performed for only 10 minutes
and the stabilizer refrigerant solenoid valve (2SOL) is
not energized (opened) during the first two minutes of
the cycle, as would be done in a Standard ADC. If the
the refrigerant pump starts before the “Primary Limited
ADC” terminates, (level switches 1F and 3F close), a
normal ADC is performed. Otherwise, when 10 minutes
have elapsed and the “Primary Limited ADC” termi
-
nates, normal chiller operation continues, unless the
ADC temperature (RT2) is greater than 150°F (65.6°C)
when it terminates, then the “Secondary Limited ADC”
(see below) is initiated.
Secondary Limited ADC in progress
Applicable only to units equipped with Buffalo pumps.
The unit is running and performing a “Secondary Lim
-
ited Automatic Decrystallization Cycle”. The secondary
limited ADC is performed for 15 minutes. It is initiated
at the completion of a “Primary ADC” (see preceding)
if the ADC temperature is greater than 150°F (65.6°C)
when the primary ADC terminates.
While the “Secondary ADC” is in effect, the stabi-
lizer refrigerant solenoid valve (2SOL) is not energized
(opened) and the steam/hot water valve is driven to
the closed (0%) position. If the refrigerant pump starts
before the “Secondary Limited ADC” terminates (level
switches 1F and 3F close), a standard ADC is performed
and the unit continues to run.
Unit is unable to perform a Limited Dilution
Cycle
The control is calling for a limited dilution cycle and it
is unable to be performed.
Unit Load has reached the Maximum Load
Limit Setpoint
The system is running in LOCAL or REMOTE oper
-
ating mode and the steam or hot water valve position
has reached and is being limited to the "Max Allowed
Loading" setpoint value that has been programmed by
the service technician. During unit commissioning, it
is sometimes necessary to temporarily limit the load
to some value less than 100% because of local or unit
conditions. Programming of this function should only
be performed by a qualified service technician.
Unit Load has reached the Remote Load Limit
Setpoint
The system is running in REMOTE mode and the unit
loading is being inhibited by the remote load limit com-
mand from a remote device. The load value that is in
effect can be viewed from the Valve Screen.
The load limit value is 100% to 10% but is limited fur-
ther by the local max. and min. load setpoints.
Unit Load is controlled by Pulldown Demand
Limit
The system is running in LOCAL or REMOTE mode.
The loading is being inhibited by the programmed
pulldown demand limit.
Unit Load is controlled by Rampdown Limit
A soft shutdown has been initiated and the system is
closing the steam/hot water control valve according to
the Rampdown Interval Timer setpoint for shutdown.
Unit load is set to 30%
TheSteam/Hot Water Control Valve is driven to 30%
open due to Generator High Pressure warning.
