1. What Is a Submersible Well Pump?

A submersible well pump is a sealed motor-and-pump assembly that sits entirely below the water line inside your well. Unlike jet pumps that sit on the surface and pull water up through suction, a submersible pushes water from below — which is inherently more efficient, quieter, and capable of lifting water from significantly greater depths.

Modern 4″ submersible systems are the standard for residential and light commercial water wells in North America. They fit inside 4-inch or larger well casings, operate completely underwater (which keeps them cool and quiet), and can deliver water from depths exceeding 750 feet at flow rates from 5 to 80+ gallons per minute.

A complete submersible system consists of several matched components: the pump end (impellers and diffusers that move the water), the motor (sealed electric motor that drives the pump shaft), the control (control box, VFD, or starter kit depending on configuration), and the accessories (wire, splice kits, torque arrestors, pitless adapters, and pressure tanks). Baker manufactures all of these components, which means you get a matched system from a single source — no finger-pointing between manufacturers if something goes wrong.

2. Why Baker?

Baker Water Systems has been building pumps in Evansville, Wisconsin since 1873. Here’s what sets their submersible line apart:

• Seven pump series covering every material, flow rate, and budget from economy thermoplastic to all-stainless-steel commercial grade — all in 4″ diameter.
• Captured stack design. Baker’s diffusers incorporate sand notches that keep abrasives flowing through the pump stack rather than grinding against internal surfaces. This is Baker’s time-proven approach to sand handling that extends pump life in wells with sandy water.
• Matched motors built to NEMA standards. Baker’s own 304 stainless steel submersible motors are designed to bolt directly to Baker pump ends with precise alignment. No adapter plates, no guessing.
• Internal check valve standard on every pump. Anti-spin check valves come built into every Baker submersible. This isn’t an add-on — it’s part of the pump.
• American-made, dealer-supported. Baker sells through authorized dealers, not big-box retail. Your customers can’t undercut your quote on Amazon.
• AutoPAC packages. Factory-assembled pump + motor + AutoDRIVE VFD systems that arrive ready to install. Matched horsepower, pre-wired, tested. No field assembly guesswork.

3. Baker Pump Series at a Glance

4. 21000 Series — No-Lead Brass

The 21000 is Baker’s flagship residential submersible and the series most well drillers and plumbing contractors specify when quality matters. The no-lead brass alloy used in the discharge casting and motor bracket exceeds current potable water standards and provides superior corrosion resistance compared to thermoplastic alternatives.

Construction Highlights

• No-Lead Brass Alloy discharge casting with built-in hex fluted guide bearing and safety eye
• Acetal check valve with Buna-N O-ring and stainless steel retention screw; threaded for easy removal; rated to 400 PSI working pressure
• Rubber discharge bearing surrounding the stainless steel shaft for superior wear resistance and shaft alignment
• Heavy-wall stainless steel shell threaded at both ends for field serviceability
• 7/16″ hex stainless steel shaft individually measured for straightness within strict tolerances
• Polycarbonate diffusers with captured stack sand notches; glass bead acetal impellers
• Stainless steel cable guard with angled top to keep leads stationary during installation

Available Configurations

Standard voltage is 230V, 60 Hz, single phase. 115V option available on ½ HP models (suffix “A”). All pumps include internal check valve and grounded motor leads.

5. 22000 Series — Domestic Thermoplastic

The 22000 is Baker’s value-oriented residential submersible. The thermoplastic discharge head and motor bracket reduce cost while still delivering reliable performance. The pump uses the same stainless steel shell, stainless steel shaft, captured stack diffuser design, and Baker motors as the premium series — the material savings come from the non-metallic end fittings.

Construction Highlights

• Reinforced thermoplastic discharge head with built-in hex fluted guide bearing and rubber insert
• 300 series stainless steel motor coupling and pump shaft
• Stainless steel pump shell with left-hand threads to prevent loosening
• Internal anti-spin check valve molded from engineered polymer with O-ring seal
• Polycarbonate diffusers with captured stack sand notches; glass bead acetal impellers
• 1¼″ FNPT discharge standard across all models

Available Configurations

HP range: ½ to 1½ HP. Flow rates: 5, 7, 10, 15, 20, and 25 GPM. Available in 2-wire and 3-wire single phase configurations. Standard 230V; ½ HP also available in 115V.

6. 23000 Series — Domestic Stainless Steel

The 23000 bridges the gap between Baker’s thermoplastic value line and the premium brass series. With a stainless steel discharge head, stainless steel shaft and coupling, and Baker’s “Diamond Design” easy-out check valve, the 23000 is the series most contractors standardize on when they want metal construction without the brass premium.

Construction Highlights

• 300 series stainless steel discharge with easy wrench design and built-in safety eye
• Baker “Diamond Design” check valve with easy-out design for field service convenience
• Stainless steel motor bracket for precise NEMA-standard motor alignment
• Polycarbonate diffusers with captured stack design; glass bead acetal impellers
• Heavy stainless steel shell threaded at both ends
• 7/16″ 300 series stainless steel hex shaft for positive impeller drive

Available Configurations

HP range: ½ to 5 HP. Flow rates: 5, 7, 10, 15, 20, and 25 GPM. Available in 2-wire single phase, 3-wire single phase, and 3-wire three phase. Three-phase options available from 1½ HP and up in 230V and 460V.

This series offers the widest horsepower range of any Baker domestic series — reaching up to 5 HP in three-wire configurations, making it suitable for deeper wells and higher-demand residential applications.

7. 24000 Series — Stainless Steel

The 24000 series comes in two configurations. The standard capacity models (5–25 GPM) cover the same flow range as the domestic series but with stainless steel construction and Noryl impellers throughout. The high flow models (35, 40, 55, 60, and 80 GPM) are where the 24000 really separates itself — delivering the volume needed for commercial buildings, farms, irrigation systems, and multi-family residential.

Standard Capacity (5–25 GPM)

• HP range: ½ to 5 HP
• Stainless steel discharge head with built-in check valve
• Noryl impellers, polycarbonate diffusers, stainless steel bowls
• 1¼″ FNPT discharge
• Available in 2-wire, 3-wire single phase, and 3-wire three phase (230V & 460V)

High Flow (35–80 GPM)

• HP range: 1 to 10 HP (varies by GPM)
• Delivery up to 124 GPM at 3450 RPM; head up to 1,300 feet
• 2″ NPT discharge (larger than domestic series)
• Stainless steel construction throughout: discharge, shell, shaft, coupling, cable guard, screen
• Noryl impellers; polyacetal bearings
• Motor bracket built to NEMA standards in stainless steel

8. 25000 Series — Thermoplastic

The 25000 series uses Noryl thermoplastic for the discharge head and motor bracket, with stainless steel bowls, shaft, coupling, cable guard, and screen. Noryl is an engineered resin with excellent dimensional stability and chemical resistance — it’s a step up from the standard thermoplastic used in the 22000 series.

Key Specifications

• HP range: ½ to 2 HP
• Flow rates: 5, 7, 10, 15, 20, and 25 GPM
• Noryl discharge head and motor bracket; Noryl impellers
• Polycarbonate diffusers; stainless steel 304 bowls, shell, shaft, coupling, strainer, cable guard
• Removable check valve; 1¼″ FNPT discharge
• Polyacetal bearing
• Available in 2-wire and 3-wire single phase; three-phase available by selecting pump end + motor + starter kit

9. 26000 Series — All Stainless Steel

The 26000 is Baker’s top-of-the-line submersible, built for demanding applications where maximum corrosion resistance and durability are non-negotiable. Every metal component — impellers, diffusers, discharge head, motor bracket, shell, shaft, screen, and cable guard — is 304 stainless steel (shaft is 431 stainless for additional hardness).

Construction Highlights

• 304 stainless steel impellers and diffusers (not polycarbonate/acetal like domestic series)
• 431 stainless steel shaft for superior hardness in the bearing area
• Stainless steel suction screen — more durable than thermoplastic screens
• Max ambient temperature: 140°F (60°C) — suitable for geothermal and high-temperature applications
• NEMA-standard mounting for direct compatibility with Baker motors
• Built-in check valve standard on all models

Available Configurations

10. Bottom Suction / Cistern Pump

Baker’s Bottom Suction-Cistern pump is a specialized submersible designed for cisterns, tanks, rainwater collection systems, and pond applications where you need to draw water from the very bottom of the vessel. Unlike standard submersibles that intake water through a side screen, the bottom suction design maximizes drawdown without compromising pump longevity.

Key Features

• Bottom suction intake for maximum drawdown in tanks and cisterns
• Handles solids up to 1/8″ — suitable for gray water and filtered effluent
• Vertical or horizontal installation
• Available in 115V and 230V (½ and ¾ HP)
• CSA listed for potable and non-potable water
• 1¼″ discharge; 2-wire configuration; quiet operation

11. How to Read a Baker Model Number

Every Baker submersible pump model number encodes the series, horsepower, flow rate, wiring, voltage, and control options into a compact string. Once you understand the pattern, you can identify any Baker pump at a glance.

Example: 21050K3A is a 21000 series (no-lead brass), ½ HP, 10 GPM flow, three-wire, 115V single phase pump with control box included.

12. Two-Wire vs. Three-Wire: Which Do You Need?

This is one of the most common questions in submersible pump selection, and the answer affects your installation cost, serviceability, and controller options.

13. Baker 4″ Submersible Motors

Baker builds their own 4-inch submersible motors in-house, ranging from ½ HP to 10 HP. These are asynchronous two-pole motors built in AISI 304 stainless steel (316 stainless for three-wire versions) with Class F insulation, IP68 waterproof rating, and a maximum operating depth of 984 feet.

Motor Construction

• Canned stator with external shell and flanges in AISI 304L/316L stainless steel; 24 slots for smooth operation
• Class F double-insulated copper wire stator windings
• Kingsbury-type thrust bearing with tilting pads in highly-resistant stainless steel, machined by spherical lapping process
• Glycol/water cooling and lubrication for thrust bearing assembly
• Squirrel-cage rotor mounted on self-centering thrust bearing (aluminum for ½–3 HP; copper for 5 HP and above)
• Removable cable connector for fast field maintenance
• NEMA 4″ flange standard on all models

Motor Ratings

14. Baker Control Boxes

Control boxes are required for all three-wire single phase submersible motors. They house the starting capacitor(s), run capacitor(s), and relay that start the motor and switch from starting to running winding. Baker offers two tiers:

Standard Control Box

• For ½ through 1 HP three-wire single phase motors
• Capacitor start configuration
• Metal casing with auxiliary contacts for control by probes
• Compact enclosure: 4.9″ × 8.2″ × 2.9″
• ½″ and ¾″ conduit knockouts

Standard CSCR Control Box

• For 1½ through 5 HP three-wire single phase motors
• Capacitor start and capacitor run (CSCR) configuration
• Larger enclosure: 8.3″ × 9.8″ × 5.9″
• 1″ and ½″ conduit knockouts

Deluxe Control Box

• For ½ through 5 HP three-wire single phase motors (4″ motors) and 5 through 15 HP (6″ motors)
• Includes magnetic line contactor, capacitor start, and capacitor run
• Thermal protection with external manual reset
• Enclosure: 8.3″ × 15.4″ × 6.3″

15. AutoDRIVE — Variable Frequency Drive

The Baker AutoDRIVE is a purpose-built variable frequency drive (VFD) for submersible well pump systems. It replaces the conventional control box and pressure switch with a single intelligent controller that varies motor speed to maintain constant water pressure regardless of demand. When someone turns on a faucet, the AutoDRIVE ramps the pump speed up. When demand drops, it ramps down. The result: no more pressure fluctuations, no more rapid cycling, reduced energy consumption, and significantly longer pump life.

Two AutoDRIVE Families

Technical Specifications

• NEMA 3R steel enclosure — outdoor/rainproof rated
• Operating temperature: -4°F to 122°F (-20°C to 50°C); 104°F for SD3-5HP2
• Efficiency: 95%
• Input: Single phase 115/230V (SD1) or Single phase 230V (SD3)
• Output: Single phase (SD1) or Three phase 230V (SD3)
• Switching frequency: 2 kHz to 8 kHz
• Large graphic display with bright backlit screen, visible in direct sunlight
• Two programmable digital inputs and two programmable analog inputs
• Setup in 5 steps or less — intuitive interface
• Dimensions: 12.25″ × 9.25″ × 4.68″ (SD1 and SD3-2HP); 17.11″ × 9.25″ × 4.68″ (SD3-3HP and 5HP)
• Weight: 13 lbs (SD1 and SD3-2HP); 15 lbs (SD3-3HP and 5HP)
• American Made

Key Benefits of Constant Pressure

• Reduced tank size. With constant-pressure operation, you no longer need a large pressure tank to buffer pressure swings. A small 2-gallon tank is sufficient.
• Eliminated pressure cycling. No more bouncing between cut-in and cut-out pressures. Your fixtures deliver the same pressure whether one faucet or four showers are running.
• Extended pump and motor life. Soft starts and variable speed operation dramatically reduce the mechanical stress of hard starts and short-cycling.
• Energy savings. The pump only works as hard as current demand requires.

16. Pumptec — Motor Protection

Pumptec is a family of electronic motor protection devices that monitor your submersible motor’s electrical signature and shut it down before damage occurs. It’s insurance for your pump investment.

Three Pumptec Models

What Pumptec Protects Against

• Low yield wells — shuts down before the pump runs dry
• Low voltage / power surges — prevents motor damage from electrical problems
• Air or gas lock — detects when the pump is cavitating
• Drop in water level — protects against drawdown below the pump intake
• Clogged well screen — detects restricted flow
• Broken shaft or coupling — detects unloaded motor condition
• Worn pump parts — detects efficiency degradation

Pumptec Plus adds protection against over/under load, over/under voltage, rapid cycling, mud or sand clogging, and faulty check valve conditions.

17. Starter Kits (Three-Phase)

Starter kits are required for all three-wire three-phase submersible motor installations. Each kit is a factory-assembled IEC starter that includes a NEMA 1 enclosure, contactor, and overload relay with the correct voltage coil for your motor.

Available Voltage Coils

Starter kits are matched to motor HP and voltage. Always verify the correct starter kit is specified for your motor — an undersized contactor or incorrect overload setting will cause nuisance tripping or fail to protect the motor.

18. AutoPAC — Constant-Pressure Packages

The AutoPAC is Baker’s factory-assembled, constant-pressure submersible pump package. It combines a Baker submersible pump end, matched Baker motor, and an AutoDRIVE VFD controller into a single SKU that arrives at the job site ready to install. The motor horsepower is balanced with the pump end horsepower — no guesswork, no mismatched components.

How It Works

Each AutoPAC model number identifies the exact pump series, horsepower, GPM, wiring, and whether it uses a pressure switch (APS suffix) or transducer (APT suffix) for pressure feedback. The AutoDRIVE controller varies motor speed to maintain your set pressure, delivering constant water pressure to every fixture in the building.

AutoPAC Availability

AutoDRIVE Compatibility Matrix

Ordering Example

23050J2-APS = 23000 series stainless steel, ½ HP, 5 GPM, 2-wire, with AutoDRIVE and pressure switch. This package arrives as a complete constant-pressure submersible system — just add pipe, wire, and a small pressure tank.

19. Pump Accessories

Baker stocks a complete line of accessories to finish your submersible installation. Key items include:

Wire & Splice Kits

• SJOOW jacketed pump leads in 2-wire and 3-wire configurations: 10, 25, 50, and 100 ft lengths
• Standard motor leads (5½’ / 67″) in 2-wire and 3-wire with ground
• Extended motor leads (106″) for 3-wire with ground
• Heat shrink splice kits for both 2-wire (12 gauge) and 3-wire (10/12/14 gauge)
• Sta-Kons crimp connectors in #12/#10 and #8/#6 sizes
• Mechanical connector sets

Torque Arrestors

Baker offers torque arrestors in sizes matched to well casing diameter. These essential devices prevent the pump assembly from spinning on startup and protect the drop pipe from torque stress.

Pitless Adapters

Stainless steel and brass pitless adapters for sanitary, frost-proof well head connections. Available in standard sizes to match your drop pipe.

Pressure Switches & Gauges

Standard 30/50 and 40/60 PSI pressure switches, including M4 models with automatic low-pressure cut-off (shuts down if pressure drops approximately 10 PSI below cut-in, requiring manual reset). Pressure gauges in various ranges for system monitoring.

Wire Sizing

Baker publishes comprehensive wire sizing charts for both single-phase and three-phase installations. Wire sizing depends on motor HP, voltage, and distance from the service entrance to the motor. Using wire that is too small will void the warranty and cause premature motor failure due to voltage drop. Always size wire using Baker’s published tables, not rules of thumb.

20. How to Choose Your Submersible System