Check Rotation (Hermetic Motor); Check Oil Pressure And Compressor Stop - Carrier 17 Start Up & Operation Manual

NOTE: When operating flood-lubricated sleeve bearings,
the bearing temperature must not be allowed to exceed
185 F (85 C) total temperature.
Under normal conditions, for the self-lube bearing,
the rate of temperature rise should be from 20° to
25° F (11° to 14° C) for the first 10 minutes after
starting up and approximately 40° F (22° C) at
30 minutes. The rate of bearing temperature rise is
a function of the natural ventilation and operating
conditions.
When the rate of bearing temperature rise is less than
2° F (1.1° C) per half-hour, the bearing temperature
is considered to be stabilized.
If the total bearing temperature exceeds 195 F
(91 C), the motor should be shut down immediately.
3. Any abnormal noise or vibration should be immediately
investigated and corrected. Increased vibration (with the
motor uncoupled from its load) can be indicative of a change
in balance due to a mechanical failure or the loosening of
a rotor part, a stator winding problem, foundation prob-
lem, or a change in motor alignment.
4. Verify that the magnetic center indicator aligns with the
shaft.
Initial Coupled Start-Up — After initial uncoupled start-up,
the following steps should be taken to ensure safe coupled
operation:
1. Follow the procedure stated in General Maintenance,
Machine Alignment section to align the motor to the driven
machine.
2. Prepare the coupling for operation in accordance with the
coupling manufacturer's instructions. Note any match marks
on the couplings and assemble accordingly. For sleeve
bearing motors, verify that the correct limited endfloat
coupling has been installed. The endfloat limits can be
found on the certified drawing.
3. Ensure that all personnel are at a safe distance from ro-
tating parts. Start the motor in accordance with instruc-
tions supplied with the motor control.
4. If the motor rotor fails to start turning in a second or two,
shut off the power supply immediately. This can result
from:
a. Too low a voltage at the motor terminals.
b. The load is too much for the rotor to accelerate.
c. The load is frozen up mechanically.
d. All electrical connections are not made.
e. Single phase power has been applied.
f. Any combination of the above.
Investigate thoroughly and take corrective action before
attempting a restart.
5. Carefully observe the vibration of the bearing housing and
any abnormal noise generator.
Note that motor vibration may not be identical to the un-
coupled values. If coupled vibration is excessive, re-
check the mounting and alignment.
6. Carefully observe the bearing temperature rise and the
movement of the oil ring.
If the bearing temperature rise and motor operation ap-
pear normal, operation should continue until the bearing
temperatures stabilize.
7. If possible, check the motor line currents for balance.
It should be recognized that each start of an induction mo-
tor subjects the motor to full inrush current with resulting
heating of the stator and rotor windings. Each acceleration
and repeated starts can produce more heat than is produced
and dissipated by the motor under full load. The starting duty
for which the motor is designed is shown by a nameplate
mounted on the motor and must not be exceeded, if long
motor life is expected. Abnormally low terminal voltage, ex-
cessive load torque and/or excessive load inertia during mo-
tor start-up can cause lengthened acceleration times during
which rotor ventilation is reduced. This can cause rotor dam-
age or can lead to shortened rotor life.
The temperature rating of the motor is shown on the main
nameplate as a temperature rise above an ambient tempera-
ture. If there is a service factor, it is also shown. If the motor
temperature switch opens, an investigation should be made
before further operation is attempted.
If the motor is of TEWAC (Totally Enclosed Water-to-Air
Cooled) design, the maximum inlet water temperature and
the water flow rate (GPM) at the air cooler must be as shown
by the certified drawing. Otherwise, the discharge air tem-
perature from the cooler (actually the ambient air for the mo-
tor as shown by the main nameplate) could be too high for
the motor to properly cool.

Check Rotation (Hermetic Motor)

1. Engage the main motor disconnect on the front of the starter
panel. The motor is now ready for rotation check.
2. After the default screen Status message states ''Ready
for Start'' press the LOCAL softkey; start-up checks
will be made by the control.
3. When the starter is energized and the motor begins to turn
over, check for clockwise rotation (Fig. 30).
IF ROTATION IS PROPER, allow the compressor to come
up to speed.
IF THE MOTOR ROTATION IS NOT CLOCKWISE (as
viewed through the sight glass), reverse any 2 of the 3 in-
coming power leads to the starter and recheck rotation.
NOTE: Starters may also have phase protection and will not
allow a start if the phase is not correct. Instead, a
Starter Fault message will occur if this happens.
Do not check motor rotation during coastdown. Rota-
tion may have reversed during equalization of vessel
pressures.

Check Oil Pressure and Compressor Stop

1. When the motor is up to full speed, note the differential
oil pressure reading on the LID 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.
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