Troubleshooting Checklist for Pumps and Control Panels
PROBLEM POSSIBLE CAUSE REMEDY
; 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. 1. Pump will not start. ; Reset the circuit breaker. ; Overload heater in starter may be ; Push to reset. tripped.
; Overload heater in starter may be burnt ; Replace the heater. out.
; Turn power off and check motor leads with megger or ohmmeter. ; May be improperly grounded. ; Check resistance of motor windings. If three-2. Pump will not start and ; Motor windings may be imbalanced. phase, all phases should show the same overload heaters trip. reading. ; Impeller may be clogged, blocked, or ; If no grounds exist and the motor windings damaged. check out satisfactorily, remove the pump from the well and check for impeller blockage.
; Pump may be air-locked. ; Turn pump off for several minutes, and then 3. Pump runs but will not shut restart. ; Lower level switch may be locked in down. closed position. ; Check to ensure level control is free.
; Selector switch may be locked in the ; Switch to the "auto" position. "hand" position.
; Open and unclog valve.
; Valve must be cleared. If there is an outside level, move it up and down.
; Discharge gate valve may be partially ; Use a sewer cleaner or high-pressure hose to clogged. clear the obstruction.
; Check valve may be partially clogged. 4. Pump does not deliver proper ; Low-speed pumps can operate in reverse capacity. direction with little noise or vibration. Correct ; Discharge line may be clogged. rotation must be established by viewing the ; Pump may be running in the wrong impeller. direction. ; Check total head with gauge when pump is ; Discharge head may be too high. 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.
; Impeller may be partially clogged resulting in sustained overload, though not high enough to ; Heat sensors in the motor may be tripped 5. Motor stops and then restarts trip the overload heater switch. due to excessive heat. after a short period, but ; Check locations and operations of level overload heaters in starter do ; Motor may be operating out of liquid controls. not trip. due to failed level control.
; The wet well may be too small or water may ; Pump may be operating on a short cycle. be repeatedly returning to the well due to a leaking check valve. Check both.
PROBLEM POSSIBLE CAUSE REMEDY
; Service voltage not on to panel.
; Turn on and check for proper voltage. ; Main or control circuit breakers tripped or 1. Pumps 1 and 2 will not run in turned off; main or control circuit fuses "hand" or "auto" position. Run ; Turn on or reset and turn on all circuit breakers. blown. lights are not on. ; Check motor heat-sensor connections and correct. ; Motor heat-sensor connections not made properly.
; Check and correct connections and cables to panel. 2. Pumps 1 and 2 will not run in ; Motors not wired properly. "hand" position. Run lights are ; Check and correct starter-coil voltage rating to ; Incorrect voltage starter coils. on. match control-circuit voltage.
; Pump circuit breaker tripped or turned off. ; Turn on or reset and turn on breaker. 3. Pumps 1 and 2 will not run in ; Pump circuit fuse blown. ; Check and replace any blown fuses. "hand" position; run lights are ; Motor starter overload tripped. ; Reset overload after checking motor. not on; one pump operates in "hand" position. ; Motor heat-sensor circuit open or not ; Check continuity of motor heat sensor; correct properly connected. connections.
; Fill or allow wet well to fill. ; Level in wet will not high enough to turn on pumps. ; Check and connect each float correctly or replace.
; Level float switches may be incorrectly ; Check and ensure air supply is on and bubbler line is connected or failed. working in wet well and has no leaks. 4. Pumps 1 and 2 will not run in "auto" position. ; Air-bubbler supply may be off or failed. ; Check and adjust pressure switches to correct levels and sequence. ; Pressure switches or sensors may not be adjusted or sequenced properly. ; Check and replace any control relay, alternator, or other device that contains a defective coil or ; Relay or other control device failed. contacts.
; No probable panel problem. ; None. 5. Alarm light or audible alarm ; Possible system problem. (e.g. discharge turns on with both pumps line is clogged) ; Check and clear check valve or line of obstruction. running. ; Temporary "high-level" condition after ; Monitor station operation until high level is reduced. power failure or influent surge.
; Test "hand" operation of non-running pump; 6. Alarm light or audible alarm refer to Problem 3. ; See remedy for Problem 3. turns on, and one or both pumps ; See Problem 4 (second, fourth and fifth ; See Problem 4 (second, fourth, and fifth remedies). are not running. causes).
; Check and correct connection to panel. ; Motor not wired properly. ; Disconnect motor and check wiring; check motor for 7. Circuit breaker tripped for motor ; Short in pump cable, wiring, or motor. shorts or grounds. power. ; Size of breaker too small and/or ambient ; Check and correct breaker size for motor and/or heat problem. provide ventilation or compensation for ambient heat.
8. Blown fuse for motor power. ; See causes of Problem 2. ; See remedies for Problem 2.
; Defective alternator relay. ; See remedies for Problem 2. 9. Pumps do not alternate. ; Improper sequencing of float switches or ; Check and correct sequence of controls to ensure pressure sensors. "off", "lead" and "lag" sequence. 10. Indicator pilot light not on during ; Pilot light bulb failed. ; Replace bulb. a 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).