Helpful Information:

Pool and spa pumps are classified as centrifugal pumps. That is, the centrifugal force that is created by spinning the water, will force the water downwards and if there is an opening or a hole, this water will get pushed forward through the hole.

The pump operates the same way. The impeller in the pump spins, shooting water out of it. As the water escapes, a vacuum is created that demands more water to equalize this force. Water is pulled from the pool or spa and sent on its way through the circulation plumbing. The hole size determines the amount of water and how fast it can escape. Also the various designs of impellers, diffusers, and volutes determine the same features in a pool pump, which is discussed later.

Pumps used for pools are self-priming, that is, they expel the air inside upon start-up, creating a vacuum that starts suction. Once water is flowing through the pump, if you close a valve on the outflow side of the pump, restricting all flow, maximum possible pressure is created. However, there is no destructive force created, the impeller simply spins in the liquid indefinitely.

Types

The three main types of motors that you find in pool and spa are:

Split-phase

When the start up power requirements are low, the motor is usually 1/4-horse power or less. It also does not require any capacitor.

Capacitor start, induction run (CSI)

This is the most commonly used motor in the pool business. This motor uses a capacitor and starting windings to start up, then these are shut down and a running winding takes over. As noted previously, the capacitor and start-up windings allow faster, stronger torque to overcome the initial resistance of the impeller against standing water, then when the water is moving and less power is needed to keep it moving, the system shuts off and the lighter running winding takes over.

Capacitor start, capacitor run (CSR)

This is the concept of the energy efficient motor. The difference between a CSR and CSI motor is that the CSR motor employs a capacitor on the running windings as well. This smoothes out the variations in the alternating current (ac) power that helps reduce heat loss in the winding. In short, CSR motors are more efficient but cost more because of the added parts. These motors are also called switch-less, because on some designs the run capacitor makes a start switch unnecessary. These are the most energy efficient motors when they have heavier wire in the windings to lower the electricity wasted from heat loss. A good way to compare energy efficiency between two motors is to compare the gallons pumped to kilowatts used. The higher the resulting number, the more efficient is the pump and motor. Kilowattage is determined by multiplying amps by voltage.

Pump And/Or Motor Removal And Reinstallation

Sometimes it is necessary to remove an entire pump and motor unit to take it apart or complete a repair. If the pump is damaged beyond your ability to repair it, you might want to take the entire unit to a motor repair shop. They can rebuild it as needed, and you can reinstall it.

Generally, to remove the pump and motor as a unit first thing is to turn off the circuit breaker. Now you will need to cut the plumbing on the suction and return side of the pump. Leave a few inches on both the sides of the cut to replumb it by slip couplings.

When installing or reinstalling the plumbing between the pump and filter keep bends and turns to a minimum. Also, do not locate the pump close to the base of the filter. When you open the filter for cleaning, water is sure to flood the motor. Lastly, try to keep motors at least 6 inches off the ground, to prevent it from flooding during rains.

The electrical connection must be removed before the pump and motor can be disengaged. Now remove the access cover to the switch plate area of the motor, near the hole where the conduit enters the motor. Remove the three wires inside the motor and unscrew the conduit connector from the motor housing. Pull the conduit and wiring away from the motor and the entire pump and motor should be free.

If there is an additional bonding wire (ground wire), it can be easily removed by loosening the screw or clamp that holds it in place.

Tape off the ends of the exposed wires, and leave a note on the breaker box, as a warning.

New Installation

Position the pump as close to the body of water and as near to water level as possible so it doesn't have to work so hard. Mount the unit on a solid, vibration-free base. Make sure there is adequate drainage in the area so that when it rains or if a pipe breaks the motor won't be drowned. Bolt or strap down the pump.

Plumb in both suction and return lines with as few twists and bends as possible, to minimize head. A gate valve on both sides is advisable to isolate the pump when cleaning other components. A check valve is essential if the unit is well above water level. Plumb the unit far enough away from the filter that it won't get soaked when you take the filter apart.

Replacing A Pump Or Motor

Having learned how to remove and break down a pump and motor in the previous sections, replacing any of the components is simply a matter of disassembling the pump down to the component that needs replacement, getting a replacement part, and reassembling the unit. Of course, if the entire pump and motor is to be replaced, you purchase the replacement as a unit and plumb it in as previously described.

Sometimes the motor will trip the circuit breaker when you try to start it. If this happens it is usually because there is something wrong with the motor; however, it could be a bad breaker or one that is simply undersized for the job and has finally worn out. To replace the motor here are the procedure:

1. Remove the shaft extender by removing the allen-head setscrews and pulling the extender off the motor shaft. Sometimes this might need persuasion. Use your large flat-blade screwdriver to pry the extender away from the motor body. Sometimes corrosion will eat away at the setscrews and extender-if it is too tough to remove, replace it.
2. Before sliding the shaft extender on the new motor, clean the motor shaft with a fine emery cloth such as you might have in your copper pipe solder kit. Apply a light coat of silicone lube to the shaft. When you put the extender on the motor shaft, the setscrews go into a groove that runs along the shaft. This groove allows the screws to grip and not slide around the shaft.
3. Now slide the new extender in place, lining up the setscrews along the channel, but do not tighten the setscrews. When you have reassembled the bracket and seal plate, seal, and impeller, you can adjust the impeller to just barely clear the seal plate face, then tighten the setscrews. Be sure the impeller is screwed tightly onto the shaft extender before making this adjustment. If it is loose, when the motor starts it will tighten the impeller, by turning it tighter against the extender, thereby tightening it against the seal plate, seizing up the unit.
4. Secure the shaft extender with your pliers or 3/8-inch box wrench and lay a rag over the impeller. Firmly hand tighten it. Reassemble the remaining pump parts and/or replumb the entire unit back into place.
5. You can access the electrical connections through the switchplate cover in the front end bell.

Conner Construction Corp. · 19008 W.Catawba Ave · Cornelius, NC 28031
Phone: (704) 896-8118 · E-mail us at: familyfunstore@aol.com