Finish Thompson SP11/15 SERIES SELF-PRIMING - Manual (Page 24)

General Notes:
• Cold water can contain dissolved air. Under high lift applications, the air can come out of solution blocking suction passages.
This can lead to lack of priming, slow priming or low flow rates.
Do not pump liquids containing ferrous metal fines.
• If magnets de-couple, stop pump immediately. Operating the pump with the magnets de-coupled will eventually weaken the
magnets.
• Do not use mismatched drive magnet assemblies (different number of magnets on inner and outer drive magnet assemblies).
• Contact our Technical Service Department at 1-800-888-3743 or by e-mail at [email protected] if you have
any questions regarding product operation or repair.
No or Insufficient Discharge
• Air leaks in suction piping
• Housing not filled with priming fluid
• Suction pipe smaller than 1 1/2”
• Suction pipe contains high spots causing trapped air pockets
• Suction pipe excessively long (flow drops as suction pipe gets longer)
• System head higher than anticipated
• Closed valve
• Viscosity or specific gravity too high
• Motor too large for magnet coupling rating (magnets uncoupled)
• Suction lift too high or insufficient NPSH
• Clogged suction line, suction strainer (if used) or impeller vanes
Insufficient Pressure
• Air or gas entrained liquid
• Impeller diameter too small
• System head lower than anticipated
• Motors speed insufficient (too low) or motor rotation incorrect (correct rotation when viewed from the fan end is clockwise)
Won’t Prime
• Did not fill housing with fluid before initially starting pump
• Closed discharge valve (valve should be open or open air vent line)
• Leak in suction piping
• Suction pipe not submerged enough (causing a vortex or exposing the end of the suction pipe)
• Lift exceeds pump ability (see SP11/15 Capabilities section)
• Suction pipe diameter too large
• Specific gravity or local atmospheric pressure (altitude/elevation) not accounted for in lift calculations
• Mismatch of inner volute and impeller diameter
• Inner volute o-ring chemically attacked, cut, brittle, etc.
• Motor rotation incorrect (correct rotation when viewed from the fan end is clockwise)
• Check valve installed too close to the pump
Section VII - Troubleshooting
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