Troubleshooting Checklist for Pumps and Control Panels
|PUMP OPERATION |
|PROBLEM |POSSIBLE CAUSE |REMEDY |
|Pump will not start. |No power to motor. |Check for blown fuse or open circuit breaker. |
| |Selector switch may be off. |Turn to "On" position. |
| |Control circuit breaker may be tripped. |Reset the circuit breaker. |
| |Overload heater in starter may be tripped. |Push to reset. |
| |Overload heater in starter may be burnt out. |Replace the heater. |
|Pump will not start and overload heaters |May be improperly grounded. |Turn power off and check motor leads with megger or |
|trip. |Motor windings may be imbalanced. |ohmmeter. |
| |Impeller may be clogged, blocked, or damaged. |Check resistance of motor windings. If three-phase, |
| | |all phases should show the same reading. |
| | |If no grounds exist and the motor windings check out |
| | |satisfactorily, remove the pump from the well and check|
| | |for impeller blockage. |
|Pump runs but will not shut down. |Pump may be air-locked. |Turn pump off for several minutes, and then restart. |
| |Lower level switch may be locked in closed |Check to ensure level control is free. |
| |position. |Switch to the "auto" position. |
| |Selector switch may be locked in the "hand" | |
| |position. | |
|Pump does not deliver proper capacity. |Discharge gate valve may be partially clogged. |Open and unclog valve. |
| |Check valve may be partially clogged. |Valve must be cleared. If there is an outside level, |
| |Discharge line may be clogged. |move it up and down. |
| |Pump may be running in the wrong direction. |Use a sewer cleaner or high-pressure hose to clear the |
| |Discharge head may be too high. |obstruction. |
| | |Low-speed pumps can operate in reverse direction with |
| | |little noise or vibration. Correct rotation must be |
| | |established by viewing the impeller. |
| | |Check total head with gauge when pump is operating; |
| | |compare against original design and previous operating |
| | |methods. If the pump has been in service for some time|
| | |and capacity falls off, remove the pump and check for |
| | |wear or a clogged impeller. |
|Motor stops and then restarts after a short |Heat sensors in the motor may be tripped due to |Impeller may be partially clogged resulting in |
|period, but overload heaters in starter do |excessive heat. |sustained overload, though not high enough to trip the |
|not trip. |Motor may be operating out of liquid due to |overload heater switch. |
| |failed level control. |Check locations and operations of level controls. |
| |Pump may be operating on a short cycle. |The wet well may be too small or water may be |
| | |repeatedly returning to the well due to a leaking check|
| | |valve. Check both. |

|CONTROL PANELS |
|PROBLEM |POSSIBLE CAUSE |REMEDY |
|Pumps 1 and 2 will not run in "hand" or |Service voltage not on to panel. |Turn on and check for proper voltage. |
|"auto" position. Run lights are not on. |Main or control circuit breakers tripped or turned|Turn on or reset and turn on all circuit breakers. |
| |off; main or control circuit fuses blown. |Check motor heat-sensor connections and correct. |
| |Motor heat-sensor connections not made properly. | |
|Pumps 1 and 2 will not run in "hand" |Motors not wired properly. |Check and correct connections and cables to panel. |
|position. Run lights are on. |Incorrect voltage starter coils. |Check and correct starter-coil voltage rating to match |
| | |control-circuit voltage. |
|Pumps 1 and 2 will not run in "hand" |Pump circuit breaker tripped or turned off. |Turn on or reset and turn on breaker. |
|position; run lights are not on; one pump |Pump circuit fuse blown. |Check and replace any blown fuses. |
|operates in "hand" position. |Motor starter overload tripped. |Reset overload after checking motor. |
| |Motor heat-sensor circuit open or not properly |Check continuity of motor heat sensor; correct |
| |connected. |connections. |
|Pumps 1 and 2 will not run in "auto" |Level in wet will not high enough to turn on |Fill or allow wet well to fill. |
|position. |pumps. |Check and connect each float correctly or replace. |
| |Level float switches may be incorrectly connected |Check and ensure air supply is on and bubbler line is |
| |or failed. |working in wet well and has no leaks. |
| |Air-bubbler supply may be off or failed. |Check and adjust pressure switches to correct levels and |
| |Pressure switches or sensors may not be adjusted |sequence. |
| |or sequenced properly. |Check and replace any control relay, alternator, or other |
| |Relay or other control device failed. |device that contains a defective coil or contacts. |
|Alarm light or audible alarm turns on with |No probable panel problem. |None. |
|both pumps running. |Possible system problem. (e.g. discharge line is |Check and clear check valve or line of obstruction. |
| |clogged) |Monitor station operation until high level is reduced. |
| |Temporary "high-level" condition after power | |
| |failure or influent surge. | |
|Alarm light or audible alarm turns on, and |Test "hand" operation of non-running pump; refer |See remedy for Problem 3. |
|one or both pumps are not running. |to Problem 3. |See Problem 4 (second, fourth, and fifth remedies). |
| |See Problem 4 (second, fourth and fifth causes). | |
|Circuit breaker tripped for motor power. |Motor not wired properly. |Check and correct connection to panel. |
| |Short in pump cable, wiring, or motor. |Disconnect motor and check wiring; check motor for shorts |
| |Size of breaker too small and/or ambient heat |or grounds. |
| |problem. |Check and correct breaker size for motor and/or provide |
| | |ventilation or compensation for ambient heat. |
|Blown fuse for motor power. |See causes of Problem 2. |See remedies for Problem 2. |
|Pumps do not alternate. |Defective alternator relay. |See remedies for Problem 2. |
| |Improper sequencing of float switches or pressure |Check and correct sequence of controls to ensure "off", |
| |sensors. |"lead" and "lag" sequence. |
|Indicator pilot light not on during a |Pilot light bulb failed. |Replace bulb. |
|function or alarm condition. | | |

|Adapted from the Submersible Sewage Pumping Systems (SWPA) Handbook, published in 1997 by the Glenview, Ill.-based Submersible Wastewater Pump |
|Association (SWPA). |