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365
SECTION 36 - SOFTWARE ENHANCEMENTS
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
36
SI0212 - SOFTWARE ENHANCEMENTS (VER 21) EFFECTIVE JUNE 2009 (CONT'D)
In this version, to avoid an OIL – LOW TEMPERATURE
DIFFERENTIAL condition from preventing a chiller
start after running at low load conditions for extended
periods, the Oil Return Solenoid (1SOL) is now cycled
closed when the oil temperature gets too low on the P, Q
and H9 compressor chillers, while the chiller is running.
An OIL RETURN MIN SETPOINT key now appears
on the OIL SUMP screen when the chiller style/com-
pressor type setpoint (on the OPERATIONS screen) is
set to P, Q or H9 compressor in SERVICE access level.
This setpoint is programmable over the range of 80.0°F
to 110.0°F (default 95.0°F) and controls the oil return
solenoid as follows:
• When the compressor is running and the oil sump
temperature is less than the oil return minimum-
setpoint, close (de-energize) the oil return sole-
noid by de-energizing K12 relay.
• When the compressor is running and oil sump
temperature is greater than the oil return mini-
mum plus 7°F, open (energize) the oil return sole-
noid by energizing K12 relay.
• During coastdown, the solenoid operation is not
changed from standard logic, it remains closed.
During startup, the operation is not changed from
standard logic, it remains closed for one minute
after system run.
An oil–saturated condenser temperature data box is
added to the OIL SUMP screen, which displays the dif-
ference between the oil temperature and the saturated
condenser temperature. This parameter is useful when
analyzing oil heater operation since it is used in the
control of the oil heater.
Variable Geometry Diffuser Operation With
Hot gas bypass
If the VGD operation is in the hot gas override state and a
stall is detected, it will transition to the stall reacting State.
In previous software versions, it would not react to stall in
the hot gas override state.
Trend Data Point Max (Y-Axis) Setup
This software version allows a greater range of the
trend maximum display value for the Y-Axis.
Heat Recovery
This software supports the new heat recovery option.
This option uses two tube bundles in the condenser.
The lower bundle is the standard condenser bundle and
is piped to the cooling tower water source. The upper
tube bundle is used to recover heat waste heat rejection
for use in a closed loop heating circuit.
On a heat recovery chiller, the chiller primary control
remains the cooling load. So, the compressor capac-
ity is still functioning according to the Leaving Chilled
Water Temperature (LCWT) setpoint.
The desired hot water temperature leaving the heating
bundles is obtained by regulating the heat rejection
through the standard lower tube bundle (sourced by
cooling tower or other water circuit). This is done by
controlling the temperature of the Return Condenser
Water Temperature (by tower bypass circuit to elevate
the temperature of the return condenser water) or vary-
ing the condenser water flow. This control can be per-
formed by the control center or an external controller.
If the OptiView Control Center is used to perform this
control, The heat recovery control valve is modulated
to control the leaving heating condenser Water tem-
perature to the hot water setpoint. The control output
to the valve is direct acting (when the leaving heating
condenser water temperature rises above the hot wa-
ter setpoint, the valve is driven more open to provide
greater cooling to the standard lower tube bundle).
The heat recovery bundle is provided with a Leaving
Heating Condenser Water Thermistor, Return Heating
Condenser Water Thermistor and a Heating Condenser
Water Flow Switch. The heat recovery circuit control is
only active when the flow sensor indicates flow.
If the chiller is equipped for heat recovery, enable the
feature on the SETUP screen. Disable the feature, if
chiller is not equipped. Once enabled, the HEAT RE-
COVERY screen is available from the CONDENSER
screen. All heat recovery parameters are displayed
on this screen. If the HEAD PRESSURE CONTROL
screen is also enabled, the head pressure parameters
appear on the HEAT RECOVERY screen (No separate
HEAD PRESSURE CONTROL screen in this configu-
ration).
A complete explanation of this feature is contained in
Service Manual (Form 160.54-M1)
,