Pump Solutions Group Neptune Series 7000 dia-PUMP MODEL 7000 - Manual (Page 14)

14
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
TROUBLE SHOOTING CHART
SYMPTOMS CAUSES REMEDIES
1. Pump Motor Will Not
Operate.
A. Blown Fuse. Check for short circuit or overload
Open thermal overload device in starter. Reset.
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.
Oil “frozen” in pump. Thaw out.
Pump Does Not Deliver
Rated Capacity A. Starved suction. Look for blockage in suction line.
Replace suction piping with larger size.
B. Leaky suction piping. Pressure test, repair or replace defective piping.
C. Excessive suction lift. Rearrange equipment location to reduce suction lift.
Liquid too close to boiling point. Lower temperature or increase suction pressure slightly.
Worn or dirty valves or seats, or both. Clean or replace.
Viscosity of liquid too high. Reduce viscosity by heating or other means.
2. Increase size of suction piping
3. Increase suction pressure slightly
Low discharge pressure. A minimum discharge pressure of 25 psi is required to insure proper
capacity control
Pump delivers erratically. Leaky suction line. Repair or replace piping.
Worn or dirty valves or seats, or both. Clean or replace valve assembly.
Excessive excursion of ball valves from
seats (indicated by ball chatter). Increase backpressure.
Insufficient suction pressure Increase suction pressure.
Raise tank level.
Liquid too close to boiling point, Reduce temperature or raise suction pressure.
Leaky system relief valve. Repair or replace relief valve
Motor overheats
thermal overload
activates, Power supply does not match motor. Check power supply against motor nameplate data.
Overload caused by operating pump
beyond rated capacity Check operating pressure against pump manufacturer data plate
maximum rating
5. Noisy Operation
1. In Pump 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.
2. In Gear Reducer Pounding noise at high discharge pressure Fluid compressibility causes reversal of load on gears at end of pressure
stroke, Not considered detrimental.
Oil level Low Flexible diaphragm punctured Replace diaphragm
Gearbox hot Gearbox temp. may rise to 150
°F. and may
be caused by various reasons and should
not raise any concern.
In case of excessive heat buildup, contact factory.