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Pumps & Motors
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How
long do motors last?
Motors
typically last an average of eight years
before needing either rebuilding or replacing.
Noisy, screeching front and/ or rear bearings will let you know when you need to do
something.
Pump
Troubleshooting Guide
This easy to read
guide will help you with some of the
most common problems that occur with
pumps.
Leaking pump?
A
very common problem is the threaded fitting carrying water out of the pump shrinking and
allowing water to drip, run and then spray. This can be
replaced with a high temp fitting
to prevent its reoccurrence. Approximately $10 parts and one hour labor. Water may also
leak from a worn out mechanical seal. This seal is the separation between the wet end and
the dry end (motor) of the pump. This
mechanical shaft seal should be replaced.
Approximately $12 for the seal and one hour labor.
Air in
pump basket?
The pump is meant to
operate air free. After some time, you may notice air in the basket, especially if you
have a clear lid to observe such things. This can reduce filtering efficiency, allow
dangerous air to build up in filter, and sometimes prevent your pump from catching prime
(being able to move water). The problem is usually located around the pump, above-ground.
Occasionally, we have to look underground for the source of the air. Approximately 1 - 4
hours labor. Sometimes air in the pump basket can be caused by something as simple as the
water level being too low in the pool. You might also want to check the
skimmer weir. This
is a plastic flap at the throat of the skimmer that keeps the debris in the skimmer when
the pump is off. If the skimmer weir is stuck it can cause the skimmer to drain and take
in air. Also check that the pump basket lid is on tight and the o-ring is
lubricated.
Pump is not pumping water like usual?
Check your
skimmer baskets for heavy debris. Make sure the
pump basket is clean and properly positioned. Some types of pumps have a pump
strainer basket that
locks into place to prevent the basket from floating and causing the pump to
cavitate, or starve for water. Sometimes when we get repair calls like this we'll find that
the pump basket is cracked and it is allowing debris to clog the pump's
impeller.
If the pump basket is cracked or
damaged, it should be
replaced. To check
the impeller, turn off the motor, remove the pump basket and reach into the
volute and feel if it is clogged
with debris. If you cannot feel for sure, you may need to
remove the motor from the pump to properly inspect the impeller. Many times you need only
remove a clamp band to separate the motor from the
pump.
Noisy
Motor?
Inside of your pump's motor are a front
bearing and a rear bearing. These bearings are sealed and cannot be re-packed or
re-lubricated. They are replaced when they begin to scream and screech. Bearings can
become damaged when the pump has run dry and overheated, or if the pump is put under high
loads. A local motor shop can replace the bearings for you, usually for under $100. One
test I do is to remove the motor from the pump, and turn it on. If it still screeches
(while not pumping anything) it is going to be the bearings. Rebuild it, or better yet,
just replace the motor. A noisy pump can also
mean
cavitation. This sounds less like
screeching and more like grinding. This condition is caused by starving the pump for
water. If possible, open more valves, or find the cause of the obstruction that is
blocking water flow into the pump. It may be the impeller. Finally, noisy pumps can be the
sound of components striking one another. The impeller can, on stub shaft models, come
loose, and hit against the impeller housing. The internal fan can break and hit against
the motor side. Both instances will resolve themselves. At 3450 rpm, it won't take long
for the fan to wear down or the impeller to chew right through the housing. These
conditions are rare, and probably will require a
new pump.
Motor will not start or turn on
First check that you have power. Is the breaker on?
Time-clock on?
All switches on? Use an electric meter to be sure that voltage is correct. Check that all
electrical connections are tight and not corroded or shorted out by bugs or debris. Again,
the use of a meter or test lamp will check this with certainty. If there is power going
all the way to the motor, the motor may have become shorted across its windings.
Motor hums but will not start
The impeller may be clogged with debris. Turn off the power, and spin the
impeller shaft. If it won't turn freely, remove the motor from the pump and clean
the impeller. If it does spin, check the
capacitor. If it is a stub shaft type
motor, check that the impeller is not hitting the impeller housing.
The capacitor is the black cylinder on the
back of the motor, although sometimes it is silver and mounted on top of the motor. Check
the capacitor for white residue or oily discharge or for bulging. Sometimes even a fine
looking capacitor can be bad. Replace with a
new capacitor of the same rating.
Finally, low voltage can be a cause of a
humming but not starting motor. New motors are wired 220 volts, so if you hook it up to
110 volts, it will only hum, or cycle. Or perhaps one of the power leads is loose, or
shorted. Check with a Multimeter to verify the correct voltage, with a variance of 10%
allowed.
Motor Cycling
If the
motor runs for a short while, shuts itself off, and turns itself back on later, it may be
overheating. Normal motor temperature is over 140 degrees, so all motors run hot. But a
cycling motor may indicate that the thermal overload is kicking it off. If this motor was
just replaced, make sure that the electrical supply connections are correct and the wire
size is correct for the voltage it is carrying. Low voltage can cause overheating.
Inadequate ventilation can cause overheating, so make sure that the air vents are
unobstructed. Usually, old motors that suddenly begin to overheat will need to be
replaced. They usually have a short inside, across the windings. And motors are just not
rewound anymore like they were in the old days.
(continued........)
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