Neptune 7000 Series, Installation Operation & Maintenance

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SECTION IV
MOTOR OPERATING CONDITIONS
7.0 The normal temperature rise for standard motors is 40°C above ambient temperature and, thus, it might appear
that the motor is operating at a higher than normal temperature. This situation is normal.
As a precaution against motor overheating, it is recommended that the pump be located where adequate
ventilation is available, It is also recommended that a MOTOR STARTER WITH THE PROPER OVERLOAD
PROTECTION BE SUPPLIED AS AN ADDITIONAL SAFETY DEVICE .
SECTION V
TROUBLESHOOTING CHART
SYMPTOMS CAUSES REMEDIES
1. Pump Motor Will Not
Operate.
A. Blown Fuse. Check for short circuit or overload
B. Open thermal overload device in
starter.
Reset.
C. Low liquid level in tank (where low
level cut-off is used).
Fill tank.
D. Broken wire. Locate and repair.
E. Low voltage. Check for too light wiring.
2. Pump Does Not Deliver
Rated Capacity
A. Starved suction. Look for blockage in suction line.
B. Leaky suction piping. Replace suction piping with larger size.
Pressure test, repair or replace defective piping.
C. Excessive suction lift. Rearrange equipment location to reduce suction lift.
D. Liquid too close to boiling point. Lower temperature or increase suction pressure slightly.
E. Worn or dirty valves or seats, or
both
Clean or replace valve assembly.
F. Viscosity of liquid too high 1. Reduce viscosity by heating or other means
2. Increase size of suction piping
3. Increase suction pressure slightly
G. Low discharge pressure A minimum discharge pressure of 25 psi is required to
insure proper capacity control
Repair or replace piping.
3. Pump delivers
erratically.
A. Leaky suction line. Clean or replace valve assembly.
B. Worn or dirty valves or seats, or
both.
Increase backpressure.
C. Excessive excursion of ball valves
from seats (indicated by ball chatter).
Increase suction pressure.
D. Insufficient suction pressure Raise tank level.
E. Liquid too close to boiling point, Reduce temperature or raise suction pressure.
F Leaky system relief valve. Repair or replace relief valve
4. Motor overheats thermal
overload activates,
A. Power supply does not match motor. Check power supply against motor nameplate data.
B. Overload caused by operating pump
beyond rated capacity
Check operating pressure against pump manufacturer
data plate maximum rating
5. Noisy Operation
5.1. In Pump A. Pump Valves. Valves must move to open and close, and they will make
a clicking noise as they operate. These noises are
sometimes amplified by natural resonances in piping
system. They are usually indications of normal valve
functioning.
5.2. In Gear Reducer A. Pounding noise at high discharge
pressure
Fluid compressibility causes reversal of load on gears at
end of pressure stroke, Not considered detrimental.