Instruction Manual

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 ow rates.

Do not pump liquids containing ferrous metal nes.

• 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 techservice@nishthompson.com if you have

any questions regarding product operation or repair.

No or Insufﬁcient Discharge

• Air leaks in suction piping

• Housing not lled with priming uid

• Suction pipe smaller than 1 1/2”

• Suction pipe contains high spots causing trapped air pockets

• Suction pipe excessively long (ow drops as suction pipe gets longer)

• System head higher than anticipated

• Closed valve

• Viscosity or specic gravity too high

• Motor too large for magnet coupling rating (magnets uncoupled)

• Suction lift too high or insufcient 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 insufcient (too low) or motor rotation incorrect (correct rotation when viewed from the fan end is clockwise)

Won’t Prime

• Did not ll housing with uid 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

• Specic 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