Pump and Motor Trouble Shooting

Some of the following is intended for information only. It is not intended to be used by anyone but a professional with experience in repairing or trouble shooting electrical motors and other electrical components.

Pump Runs, But Pumps No Water

Most Obvious

  • Check for dirty filter--High pressure reading.
  • Check for clogged or skimmer basket--Low pressure reading.
  • Check for closed valve
  • Check for "Air Lock" in suction line. (particularly if line is above pump level, remove  lid from strainer pot to relieve air.
  • Water level too low (below skimmers)
If you have checked all the above, fill pump housing and strainer pots with water and check to see if it leaks down, than check (A) below. If it does not leak down, check (B) below.
(A) Next Check
  • Air suction leak-- Low or pulsating pressure reading
    -Cracked pipe on suction side. (Check all exposed pipes)
    -Loose fitting on suction side. (Check all exposed pipes)
    -Bad O-rings or gaskets on pump or traps.
    -Cracked pump or strainer housing
    -Warped cover on strainer housings

 

(B) If Everything Above Appears Ok
  • Suction line could be clogged. (Stick garden hose into suction line at pump strainer pot, pressure blast debris if clogged.)
  • Pump could be defective. Check pump internally for any of the following:.
    -Clogged impeller
    -Badly worn or broken impeller
    -Check for excessive wear on any wear rings or diffusers.
(C) If Installation Is New
  • Total head of the plumbing system is higher than the designed head of the pump
  • A Check-Valve may be defective or plumbed backwards.
  • Suction-Lift required is more than the pump can attain.
GENERAL TIPS
Does pump sound different than normal? Could be air cavitation on the suction side, caused by one or more of the symptoms above. Or, if the pump sounds like its working hard the cause is usually back pressure from a dirty filter.

Look for gray or white residue from leaks around  the pump indicating leaks from a seal or O-ring.

 

Pump Runs, But Pumps Low Water Flow

Most Obvious

  • Check for dirty filter--High pressure reading.
  • Check for clogged or skimmer basket--Low pressure reading.
  • Check for closed valve
  • Check for "Air Lock" in suction line. (particularly if line is above pump level, remove  lid from strainer pot to relieve air.
  • Water level too low (below skimmers)
If you have checked all the above, fill pump housing and strainer pots with water and check to see if it leaks down, than check (A) below. If it does not leak down, check (B) below.
(A) Next Check
  • Air suction leak-- Low or pulsating pressure reading
    -Cracked pipe on suction side. (Check all exposed pipes)
    -Loose fitting on suction side. (Check all exposed pipes)
    -Bad O-rings or gaskets on pump or traps.
    -Cracked pump or strainer housing
    -Warped cover on strainer housings

 

(B) If Everything Above Appears OK
  • Suction line could be clogged. (Stick garden hose into suction line at pump strainer pot, pressure blast debris if clogged.)
  • Pump could be defective. Check pump internally for any of the following:.
    -Clogged impeller
    -Badly worn or broken impeller
    -Check for excessive wear on any wear rings or diffusers.
(C) If Installation Is New
  • Total head of the plumbing system is higher than the designed head of the pump
  • A Check-Valve may be defective or plumbed backwards.
  • Suction-Lift required is more than the pump can attain.
GENERAL TIPS
Does pump sound different than normal? Could be air cavitation on the suction side, caused by one or more of the symptoms above. Or, if the pump sounds like its working hard the cause is usually back pressure from a dirty filter.

Look for gray or white residue from leaks around  the pump indicating leaks from a seal or O-ring.

 

PUMP RUNS, BUT NOISY

Isolate Sounds

If sound is coming from motor
  • Could be bad bearings
  • Check for dirty or clogged cooling fan (Openings or slots near front of motor)
  • Could be a bent shaft (Could have been dropped or sometimes they warp if overheated)
If sound is coming from the pump
  • Cavitation from low water flow (see low water flow section above)
  • Bent or broken impeller
  • Object in pump housing
  • Broken or bad mechanical seal
Listen to the sounds with a mechanics stethoscope or my favorite, a large long shafted screwdriver. Place the metal end of the screwdriver on the object you want to listen to, and the handle end in your ear. As you move the metal end around you can hear the sound changes. CAUTION: Don't get the listening device into moving or electrical parts.

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MOTOR DOES NOT RUN

CAUTION: Some of the following procedures may require an electrician or a person qualified for motor repair

Most Obvious

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  • Check to see if on/off switch is on
  • Check timers
  • Check circuit breakers (Turn off then back on)
  • Is electricity actually getting to terminals on motor.
If electricity is not getting to motor, you have an electrical problem, call electrician.
If electricity is getting to terminals on motor proceed to the following
Next Check
  • Check voltage: (Caution: should be done by an electrician)
-Remove motor end canopy
-Set meter for nameplate voltage
-Put one lead on L1 and the other lead on L2
  • Voltage should be within 10% of nameplate voltage
  • If voltage is OK proceed to the following

Caution !!!!! Disconnect Power for next set of tests

  • Check Start-Capacitor (Not all motors have one)Electric Disconnected
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-Slip heavy piece of paper between starter points
-Discharge capacitor by touching the two leads with an insulated screwdriver. Discarge capacitor each time you test.
-Set ohmeter to R x 1K
-Atach one probe to each lead of capacitor, meter needle should move rapidly to right anad slowly move back to the left. (If using a digital meter, readings should start low than rapidly increase to maximum.)
-Replace capacitor if bad.
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Next Check
  • Check thermal protector-Electric Disconnected
-Set ohmeter to R x 1
-Resistance between terminals 1 & 2 should be approximately 0
-Resistance between terminals 2 & 3 should be approximately 0
-Replace if either value exceeds 1 ohms
Next Check
Mechanical starter switch check-Electric Disconnected
  • Rotating Governor
-Make sure there are no obstructions preventing the proper operation of the rotating governor.
-Check wiring and make sure it is clear of the governor
-Check governor and make sure weight flipper is free to move.
  • Starter Points
-Check switch points for severely burned or pitted surfaces
-Visually check the action of the points and the governor
-Points should be closed with motor not running
-Reach in and raise the governor weight until it touches the stops on the governor.
-The clearance between the projection on the governor and the white button on the points should be .030" to .040" (about the thickness of a paper clip wire)
  • Starter Switch adjustment
-Turn the adjustment screw until the correct clearance is reached

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Next Check
Winding Continuity
  • The following procedures are for a typical motor with the following specifications:
-Single Phase
-dual voltage
-capacitor start
-single speed
-terminal board connected for 230V
  • To test for winding continuity
 
-Set ohmeter to R x 1K
-Slip paper between the points
-Discharge capacitor
-Take the following readings
  1. L1 to A------ & ------A to yellow
-Resistance should be the same
  1. Yellow to Red-------& ------L1 to Red
-Resistance should be the same
If reading differ, check all leads and wires for breaks, loose connections, etc., which can be repaired. The problem could be an open or shorted winding, in which case, the motor should be replaced.

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