Carrier 19XR,XRV Hermetic Centrifugal Liquid Chillers - Manual (Page 65)

65
Dry Run to Test Start-Up Sequence
For electro-mechanical starters.
1. Disengage the main motor disconnect (CB1) on the start-
er front panel. This should only disconnect the motor
power. Power to the controls, oil pump, and starter con-
trol circuit should still be energized.
2. Observe the default screen on the CVC/ICVC: the status
message in the upper left-hand corner reads, “Manually
Stopped,” Press the
or softkey to start.
If the chiller controls do not go into a start mode (“Unoc-
cupied Mode” is displayed) go to the SCHEDULE screen
and override the schedule or change the occupied
time. Press the
softkey to begin the start-up
sequences.
3. View the STARTUP display screen and verify the chilled
water and condenser water pumps have energized.
4. Verify the oil pump has started and is pressurizing the
lubrication system. After the oil pump has run about
11 seconds, the starter energizes (COMPRESSOR START
CONTACT is closed) and goes through its start-up
sequence.
5. Check the main contactor (1M) for proper operation.
6. The PIC II eventually shows an alarm for motors amps
not sensed. Reset this alarm and continue with the initial
start-up.
For Benshaw Inc. solid-state starters:
1. Close the main motor disconnect (CB1). Voltage will be
applied to the compressor motor but the SCRs will not
fire (compressor motor will not rotate). Enter MENU 4 in
the Benshaw RediStart MICRO™ Menu structure at the
Benshaw display (see Input Service Configurations,
Change The Benshaw RediStart MICRO Software Con-
figuration page 57). Select Dry Run Mode and scroll to
YES.
2. Follow steps 2 through 4 for the electro-mechanical start-
ers. When the Ramp Time is set for less than 10 seconds
COMPRESSOR RUN CONTACT will close.
3. The PIC II eventually shows an alarm for motors amps
not sensed. Reset this alarm and enter MENU 4 in the
Benshaw display. Select Dry Run Mode and scroll to NO.
Continue with the initial start-up.
Check Motor Rotation
1. Engage the oil pump circuit breaker (CB3) located inside
the right hand side of the starter panel.
2. Then engage the control power circuit breaker (CB2) lo-
cated in the same section of the starter cabinet.
3. Finally close the main motor disconnect (CB1) on the
front of the starter panel.
4. The ISM mounted in the electro-mechanical starters
checks for proper phase rotation as soon as power is
applied to the starter and the PIC II controls power up.
Solid-state starters have phase protection and do not per-
mit a start if the phase rotation is not correct.
5. An alarm message will appear on the CVC/ICVC if the
phase rotation is incorrect. If this occurs reverse any 2 of
the 3 incoming power leads to the starter and reapply
power. The motor is now ready for a rotation check.
6. After the default screen status message states ‘Ready to
Start’ press the softkey. The PIC II control per-
forms start-up checks.
7. When the starter is energized and the motor begins to
turn, check for clockwise motor rotation (Fig. 33).
Check Oil Pressure and Compressor Stop
1. When the motor is at full speed, note the differential oil
pressure reading on the CVC/ICVC default screen. It
should be between 18 and 30 psid (124 to 206 kPad).
2. Press the Stop button and listen for any unusual sounds
from the compressor as it coasts to a stop.
To Prevent Accidental Start-Up — A chiller STOP
override setting may be entered to prevent accidental start-up
during service or whenever necessary. Access the MAINSTAT
screen and using the
or softkeys, high-
light the CHILLER START/STOP parameter. Override the cur-
rent START value by pressing the
softkey. Press the
softkey followed by the softkey. The word
SUPVSR! displays on the CVC/ICVC indicating the override
is in place.
To restart the chiller the STOP override setting must be re-
moved. Access the MAINSTAT screen and using or
softkeys highlight CHILLER START/STOP. The
3 softkeys that appear represent 3 choices:
•
— forces the chiller ON
• — forces the chiller OFF
• — puts the chiller under remote or schedule
control.
To return the chiller to normal control, press the
softkey followed by the softkey. For
more information, see Local Start-Up, page 46.
The default CVC/ICVC screen message line indicates
which command is in effect.
Check Chiller Operating Condition — Check to
be sure that chiller temperatures, pressures, water flows, and
oil and refrigerant levels indicate the system is functioning
properly.
Instruct the Customer Operator — Ensure the op-
erator(s) understand all operating and maintenance procedures.
Point out the various chiller parts and explain their function as
part of the complete system.
COOLER-CONDENSER — Float chamber, relief valves, re-
frigerant charging valve, temperature sensor locations, pressure
transducer locations, Schrader fittings, waterboxes and tubes,
and vents and drains.
CCN LOCAL
LOCAL
LOCAL
Do not check motor rotation during coastdown. Rotation
may have reversed during equalization of vessel pressures.
NEXT PREVIOUS
SELECT
STOP ENTER
NEXT
PREVIOUS
START
STOP
RELEASE
RELEASE ENTER
Fig. 33 — Correct Motor Rotation