18
When the cooler pump control is “ON,” the cooler pump relay
will be energized when the chiller enters an “ON” mode (i.e.,
ON LOCAL, ON TIME, ON CCN). The cooler pump relay
will remain energized for 30 seconds after all compressors stop
due to off command. In the event a freeze protection alarm is
generated, the cooler pump relay will be energized whether
cooler pump control is configured “ON” or “OFF.” The cooler
pump relay is also energized anytime a compressor is started as
well as when certain alarms are generated. The cooler pump re-
lay should be used as an override to the external pump control if
cooler pump control is not utilized.
30HXC brine applications below 32 F (0° C) leaving brine
temperature require cooler pump control. To reduce the possi-
bility of condenser freeze-up the cooler pump must be stopped
or isolation valve closed in the event of loss of condenser water
flow.
If cooler pump control is turned “OFF” or “ON” and the
chilled water flow switch/interlock does not close within 5 min-
utes after the unit is enabled and in an “ON” mode, alarm A200
will be generated. If cooler pump control is turned “ON” and
the chilled water flow switch/interlock is closed when the unit
is enabled and enters an “ON” mode alarm A202 will be gener-
ated. Alarm A201 will be generated whenever the cooler pump
interlock is open for at least 10 seconds during chiller operation.
CONDENSER PUMP CONTROL (CNP.I AND CNPC,
Configuration Mode/sub-mode OPT1) — Factory defaults for
both condenser pump control and condenser flow switch are
set to “NO CONTROL” and “OFF,” respectively. The
condenser pump can be controlled in one of two ways: In the
first method, (CNPC set to “ON WHEN OCCUPIED”) the
pump can be controlled like the cooler pump. It is turned on
whenever the machine is in an “ON” mode and turned off
30 seconds after all compressors stop and the machine is in an
“OFF” mode. The second method (CNPC set to “ON WITH
COMPRESSORS”), will energize the condenser pump output
when the first compressor is started and deenergize the output
30 seconds after the last compressor stops.
When configured for a condenser flow switch/interlock
(CNP.I set to “ON”), an alarm A159 is generated if the input
does not close within one minute after the machine enters an
“ON” mode, or within one minute after the condenser pump
relay is energized when configured “ON”. Alarm A159 is also
generated if the flow switch/interlock opens for more than
10 seconds during chiller operation.
30HXC brine applications below 32 F (0° C) leaving brine
temperature require condenser pump control to be configured
to “ON WHEN OCCUPIED” and condenser pump interlock to
be “ON”. A condenser water flow switch must be installed and
wired to TB2 terminals 5 and 6. The condenser pump output
remains energized for 30 minutes after the Enable/Off/Remote
Contact switch is placed in the “OFF” position or the Remote
Contacts are opened allowing refrigerant pressure equalization.
BRN.L (Configuration Mode, sub-mode SLCT) must be
configured to YES if Brine FIOP is installed. This will energize
liquid line solenoid valves on brine units when the condenser
pump is “ON” and when the compressors are “OFF”. Liquid
line solenoids are included as part of the Brine FIOP.
Flow Sensor —
The factory-installed flow sensor/switch
should not require adjustment.
Proper operation of this sensor/switch is necessary to allow
the unit to operate and provide running freeze protection for the
unit. When power is supplied to the switch, the amber LED in
the center of the display will be illuminated.
When there is chilled water flow, but the flow is inadequate
to close the switch and allow unit operation, one red LED will
illuminate. A red LED can also indicate inoperative pump(s),
closed valve, clogged strainer or air in the system.
When the first green LED is illuminated, the switch is
closed and the unit will start and run. Various conditions can
cause variations in flow and allow the switch to open and cause
a “nuisance trip”. Greater constant flow will help reduce
nuisance tips.
Measure the pressure drop across the cooler and use
Appendix E to determine the cooler flow rate then determine if
the flow rate is adequate for the application. A green LED does
not mean minimum flow requirements have been met.
Cooler Heater Control —
Factory-installed cooler heat-
ers can be ordered for the 30GXN,R chillers. The number of
heaters depends on the size of the machine. The control system
operates the heaters in response to the saturated suction
temperature of each circuits as well as Entering and Leaving
Water Temperature.
The cooler heater will be energized if the unit is OFF (no
mechanical cooling) and either of the following two conditions
has been met:
•
The Saturated Suction Temperature in either circuit is
less than BR.FZ
Brine Freeze Point
(Configuration
Mode, Sub-mode SERV), and the unit has been off for
more than 30 seconds.
•
Entering or Leaving Water Temperature is less than
BR.FZ + 3 ºF (1.7 ºC). The heaters will remain on until
both Entering and Leaving Water Temperatures equal or
exceed 120 ºF (48.9 ºC). The heaters will energize again
when both water temperatures are below 110 ºF
(43.3 ºC). Cooler flow must be established in order to
de-energize the cooler heaters.
•
If the Entering or Leaving Water Thermistor has failed,
the heaters will stay on.
If after 15 minutes of operation, the Saturated Suction
Temperature for both circuits is not greater than BR.FZ + 10 ºF
(5.6 ºC), the Cooler Pump will be commanded ON in attempt
to increase the water temperature.
The cooler heaters will be deenergized if the unit is ON
(mechanical cooling is ON) or if the Saturated Suction Temper-
ature for both circuits is greater than BR.FZ + 10 ºF (5.6 ºC) for
at least 10 minutes.
Oil Heater Control (30GXN,R Units Only) —
Standard feature that controls oil temperature based on the dis-
charge gas temperature (DGT) thermistor. Heaters turn on
when DGT < 95 F (35 C) and turn off when DGT > 100 F
(37.8 C) and compressors are off. The heater is deenergized if
the oil level switch is open.
Navigator Display Module Usage (See Fig. 10
and Tables 11-24B) —
The Navigator module provides
a mobile user interface to the
Comfort
Link™ control system.
The display has up and down arrow keys, an
key, and an
key. These keys are used to navigate through the different
levels of the display structure. See Table 11. Press the
key until ‘Select a Menu Item’ is displayed to move through
the top 11 mode levels indicated by LEDs on the left side of the
display.
Pressing the
and
keys simultaneously will put
the Navigator into expanded text mode where full meaning of
all sub-modes, items and their values can be displayed. Press-
ing the
and
keys when the display says ‘Select a
Menu Item’ (Mode LED level) will return the Navigator to its
default menu of rotating display items (those items in the
VIEW sub-mode under the Run Status mode). In addition, the
IMPORTANT: If the cooler pump control relay output is
not wired to control or override the operation of the
chilled water pump an OFF DELAY of 10 minutes must
be provided after the chiller is disabled to maintain
cooler water flow during the pump down period.
ESCAPE
ENTER
ESCAPE
ESCAPE
ENTER
ESCAPE
ENTER
