Main Motor Operation; Main Motor Maintenance And Repair; Periodic Inspection Of The Main Motor - Sullair ShopTek ST18 Operation & Maintenance Manual

ST18 & ST22 (U.S.A. & Mexico) Operation & Maintenance Manual
See the main motor nameplate and the other topics in
this section for additional information about operating
conditions.
6.5.1

Main motor operation

• The main motor must be grounded correctly.
The ground wire of the main motor is already
connected in the electric cabinet. You only
need to connect this connection point to your
ground.
• The lead wires of the main motor are clearly
marked.
• The main motor connection diagram is on the
motor nameplate.
• If the voltage and frequency of the power
source for the main motor match the require-
ments on the motor's nameplate, the motor can
operate continuously at the rated power × utility
coefficient. If the power source's frequency
deviates from the value on the nameplate by
1%, or under voltage or over voltage exceeds
10%, the motor is not guaranteed to deliver that
output power continuously.
• The compressor motor runs best when imbal-
ance among the three phases does not exceed
1%.
• A current detection device in the electrical cabi-
net of the compressor provides motor overload
protection.
• The motor should not make intermittent or
unusual noises or vibrations when running
(either at no load or load).
6.5.2

Main motor maintenance and repair

• The operating environment should be dry, the
motor surface should be clean, and the motor's
air inlet should not be blocked by dust or fibers.
• When the motor overload protection device
shuts down the compressor, do not restart the
compressor until you find and eliminate the
cause of the overload.
• Make sure bearings are well lubricated. Grease
should be added or replaced every 2000 hours.
If grease becomes too hot or deteriorates dur-
ing operation, replace it. Before adding grease,
clean the bearing and cap slot. Different motors
use different types of grease. See the motor
nameplate for the type of grease needed.
• Replace the bearings at the end of their service
life. (At the end of the bearings' service life, the
88291013-137 R05
Subject to EAR, ECCN EAR99 and related export control restrictions.
motor will create significantly more noise and
vibration.)
• After any motor faults occurs, contact your Sul-
lair representative.
6.5.3 Periodic inspection of the main
motor
You should inspect the main motor yearly to ensure that
the motor is operating correctly and in good condition.
Isolate the compressor from the power supply
before making any repairs or adjustments to the
drive coupling.
You should inspect the motor every six months if the
compressor is exposed to any of these conditions:
• Corrosive or conductive dust
• Excessive dirt or dust (the accumulated dust
may interfere with the compressor's ventilation)
• Chemical smoke, steam, salt mist, or oil mist
• A very wet or very dry atmosphere
• Radiant heat
• Pests or mold
You should also inspect the main motor every six months
when the compressor runs under nonstandard condi-
tions, such as:
• The rated voltage and/or frequency often devi-
ates from the limits set under Section 6.5.1:
Main motor operation.
• The compressor is in a room with either poor
ventilation or an ambient temperature over
40°C (104°F).
• The motor starts and stops often because of
frequent fluctuations in air demand.
6.5.3.1 Periodic inspection checklist
• Add or change the main motor bearing grease
according to the maintenance schedule.
• Inspect the bearing seal and eliminate oil leaks
you find.
• Check the end cover and the shroud for con-
densation, deposited water, iron rust, or corro-
sion.
• Check for excessive dust or other foreign mate-
rial.
6: Maintenance
WARNING
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