71
30HXC machines:
•
Check Condenser Water Regulating Valve operation, if
equipped.
•
Clean condenser tubes if appropriate.
•
Check condenser water strainers, clean as necessary
PRE-START-UP PROCEDURE
System Check
1. Check all auxiliary components such as the chilled fluid
circulating pump, air-handling equipment, or other equip-
ment to which the chiller supplies liquid. Consult the
manufacturer’s instructions. If the unit has field-installed
accessories, be sure all are properly installed and wired
correctly. Refer to the unit wiring diagrams.
2. Check the cooler flow switch for proper operation (item
‘FLOW’, Inputs mode under sub-mode GEN.I). Ensure
sensor contacts close when the pump is on and open
when the pump is turned off. A flow switch is factory
installed on all models with two or more pass coolers. For
single pass cooler models, the flow switch is factory
supplied for field installation with factory-supplied
victaulic nozzles.
3. Open the discharge and liquid valves in each circuit. Both
shutoff valves are in-line ball type and are open when
stem is parallel with the refrigerant flow.
4. If factory-installed suction service valves are installed,
open the suction service valves in each circuit. Service
valve is located below the compressor in the cooler
suction connection flange. To operate the valve, first
remove the cap. Use a back-up wrench on the packing
gland to prevent loosening while removing cap. Loosen
the jam nut. Rotating the valve handle clockwise will
close valve and counterclockwise will open valve. When
closing the valve, the linkage arm must swing past center
of the actuator shaft cam to seat and prevent accidental
opening of the valve. Tighten the jam nut. See Fig. 38
and 39.
5. Before filling the system with fluid following a winter
shutdown, check the chilled water loop for pressure.
Higher than atmospheric pressure could be the result of a
refrigerant leak in the cooler.
6. Open the oil shutoff valves located by the oil pre-filter,
and the ball valve to each compressor.
7. Check the tightness of all electrical connections. Check
incoming power supply for proper nameplate voltage.
8. Check to ensure the unit is level per the installation
instructions.
9. Check all field configuration data and set points.
10. Enter correct date, time, and operating schedule(s).
11. Verify operation of solenoids, pumps, valves, compres-
sors, fans, etc. as listed in the Start-Up Checklist.
12. Open condenser water valves. Check condenser water
pump for proper operation (30HXC).
START-UP AND OPERATION
Actual Start-Up —
Actual start-up should be done only
under supervision of a qualified refrigeration mechanic and
qualified Carrier Comfort Network personnel.
1. Set leaving fluid temperature. No cooling range adjust-
ment is necessary.
2. Start chilled fluid pump and condenser pump (30HXC) if
not controlled by unit.
3. Switch Enable/Off/Remote Contact switch to Enable or
Remote Contact.
4. Provided there is a load on the chiller, allow the machine
to operate and confirm that everything is functioning
properly. Verify that the leaving fluid temperature agrees
with the cooling set point (1 or 2), or if reset is being used,
the modified set point. Chiller is controlling to the Con-
trol Point (item ‘CTPT’) displayed on the Navigator.
Operating Sequence —
The chiller is started by
switching the Enable/Off/Remote Contact switch to either
Enable or Remote Contact position. If cooler pump control is
enabled, the cooler pump is started. If condenser pump control
(30HXC) is enabled, the condenser pump is started. On a
command for cooling, the oil pump is turned on to start the
pre-lubrication process. After 20 seconds, the oil solenoid is
opened and the control reads the oil pressure from the
transducer and determines if sufficient pressure has been built
up. If there is not sufficient pressure, an alarm is generated
after the second attempt and the compressor is not started.
IMPORTANT: Before beginning Pre-Start-Up or Start-
Up, complete the Start-Up Checklist for the 30GX,HX
Liquid Chillers on pages CL-1 to CL-10. This Checklist
assures proper start-up of the chiller, and provides a
record of unit condition, application requirements, sys-
tem information and operation at initial start-up. The
checklist should be removed from the manual and kept
with the job file for future reference.
IMPORTANT: DO NOT ATTEMPT TO START THE
CHILLER UNTIL THE FOLLOWING CHECKS
HAVE BEEN COMPLETED.
DO NOT make any changes to the factory-installed com-
pressor power wiring in the control box or at the compres-
sor junction box. Doing so will cause permanent damage to
the compressor and will require compressor replacement.
Proper phasing has already been checked at the factory.
SIDE VIEW
FRONT VIEW
BRASS CAP
JAM NUT
VALVE HANDLE
C
O
C
O
open
close
Caution: loosen stem locknut
(L.H. thread) before opening
Fig. 38 — Suction Valve Detail
Fig. 39 — Suction Valve Handle Details
