Multiquip AP6 Series - Manual (Page 76)

PAGE 76 — AP6/AP8 SERIES TRASH PUMPS • OPERATION AND PARTS MANUAL — REV. #0 (06/11/14)
TROUBLESHOOTING (PUMP)
Troubleshooting (Pump)
Symptom Possible Problem Solution
Pump fails to prime – low vacuum.
Insuffi cient product at inlet (submergence)? Lower strainer deeper in sump
Pump drain valve left open? Close drain valve
Priming chamber valve closed? Open priming chamber valve
Speed too low? Increase within recommended limits
Air leak on suction side? Fix leaks
Air lock? Vent air/install air release valve
Discharge non return valve not seating? Clear obstruction/check for wear
Venturi or priming chamber bumper plugged? Clear any obstructions
Mechanical seal leaking? Check and repair/replace as required
Pump fails to prime – high vacuum
Strainer clogged? Clean strainer
Excessive suction lift? Lower if possible or select larger piping
Pump takes a long time to prime
Speed too low? Increase within recommended limits
High suction lift and/or long hose length? Reduce if possible
Air leak on suction side? Fix leaks
Discharge check valve obstructed or worn? Clear obstruction/check for wear
Worn air compressor or venturi? Repair/replace
Pump fails to hold prime when turned off
End of hose/strainer out of fl uid? Check pipe/strainer submergence
Discharge check valve obstructed or worn? Clear obstruction/check for wear
Air leak on suction side of pump? Fix leaks
Priming chamber non return valve obstructed? Clear obstruction/check for wear
Reduced performance
Vortexing/improper submergence? Lower strainer deeper in sump
Air leaks on suction side? Clear any obstructions
Strainer or impeller partially clogged? Lower if possible or select larger piping
Excessive suction lift? Increase within recommended limits
Speed too low? Lower if possible or select larger piping
Discharge head too high? Check and adjust/repair as required
Pump internals worn? Adjust/replace as necessary
Pump overheating
Strainer clogged? Clear any obstructions
Cavitation (improper suction design)? Correct suction problems
Discharge head too high? Lower if possible or select large piping
Pump internals worn? Check and adjust/repair
Air lock? Vent air/install air release valve
Excessive pump vibration or noise
Material lodged in impeller (out of balance)? Clear any obstructions
Discharge head too high? Lower if possible or select large piping
Cavitation (improper suction design)? Correct suction conditions
Misalignment? Align all rotating parts