Pool Info: Pumps & Motors - Page 2
Pumps & Motors (cont.)
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.
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.
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.
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........)