Grundfos 300S SP 6 in Submersible Well Pump

The Grundfos 300S is the 300 GPM class of the Grundfos SP submersible range, built for 6 in and larger wells. Pump and impellers are AISI 304 stainless steel. Each build here is a complete pump: the 300S pump end and a Grundfos submersible motor, supplied together under one part number, with a 3-4 in NPT discharge.

Typical uses listed by Grundfos include groundwater supply, irrigation, residential water pressure boosting and municipal wells.

The 300S range here runs on 4 in Grundfos MS4000 motors (3-10 HP) and 6 in Grundfos MS6000C motors (7-1/2-40 HP). The motor size for each build is shown in the selector and in the Models & Ratings table.

Single-phase builds (3-5 HP, 230V) use a 3-wire motor and run through a Grundfos control box, sold separately. Three-phase builds are available at 230V or 460V.

24 months from date of installation, but not more than 30 months from date of manufacture. In Grundfos's words, products are “warranted to the original user only to be free of defects in material and workmanship”; the full terms are in the installation and operating instructions on the Data Sheet tab.

Each 300S serves one well as a single unit. For a duty/standby pair across two wells, or a flow outside what one 300S carries, send us the duty: the 90S, 160S and 240S cover lower flows in the same 6 in well range, and the 385S and 475S cover higher flows in 8 in wells, and we will size the set with you.

The model code reads flow class, horsepower and stages: 300S150-3 is the 300S with a 15 HP motor and 3 stages. The same model can come in more than one build, so order by part number. In the selector, choose horsepower and motor size first, then voltage and phase (the button shows the wiring and whether a control box or starter is needed), then the model and stage count. The part number for every build is in the Models & Ratings table.

• 300S75-2 and 300S100-3A come on more than one motor size (4 in and 6 in). Each build has its own part number and pump end.
• 300S30-1B, 300S50-2BB, 300S100-3A, 300S150-4AA, 300S200-5AA, -6B, 300S250-7AA and 300S300-9B: letters after the stage count mean reduced-diameter impellers, which trim the head to fit a duty. The selector shows the full model, letters included.