1. Anatomy of a Submersible Pump System

Before we talk products, let’s make sure we’re speaking the same language. A submersible well pump system has five core components that work together. Remove any one and nothing works. Mismatch any two and you’re looking at premature failure or poor performance.

Baker manufactures the first three components and bundles them into complete systems. Drop pipe and pressure tanks are typically sourced separately, though Baker does offer a full line of diaphragm pressure tanks.

2. Baker Submersible Pumps — Complete Assemblies

When most people say “submersible pump,” they mean the complete assembly: pump end bolted to a motor, ready to drop in the well. Baker offers this as a single-SKU product across six different pump series, covering everything from a 1/2 HP cabin well to a 10 HP commercial system pushing 80 GPM.

The Six Pump Series

How to Read a Baker Model Number

Every Baker model number encodes the pump’s specifications. Let’s decode 24200R3 as an example:

GPM Letter Codes

Optional Suffix Codes

• No suffix: Standard 230V, single phase, 60 Hz with control box (three-wire) or motor leads (two-wire).
• Z: 230V three-phase motor. Includes starter kit instead of control box.
• Y: 460V three-phase motor. Includes starter kit.
• LB (Less Box): Single-phase pump shipped WITHOUT the control box. Use when you already have a compatible box or are connecting to a VFD.
• LS (Less Starter): Three-phase pump shipped WITHOUT the starter kit. Use when you have an existing starter or VFD.

Two-Wire vs. Three-Wire Motors

This is the most fundamental decision in submersible pump selection, and it’s the one most commonly misunderstood.

3. Baker Pump Ends — The Hydraulic Component

A pump end is the top portion of the submersible assembly — the part with the impellers, diffusers, bowls, and discharge head. It’s the component that does the actual work of moving water. Baker sells pump ends separately for two reasons: first, if your pump end fails but the motor is still good, you only replace what’s broken. Second, pump professionals sometimes match a pump end with a specific motor for custom applications.

What’s Inside a Pump End

• Discharge Head: Stainless steel 304, threaded NPT connection (1-1/4″ on standard 5–25 GPM, 2″ on high-flow 35–80 GPM).
• Check Valve: Built-in stainless steel check valve prevents backflow. Eliminates the need for an external check valve at the wellhead.
• Impellers: Stainless steel (23000/26000 series) or Noryl engineered thermoplastic (24000/25000 series). The number of stages determines the pump’s pressure capability.
• Diffusers: Polycarbonate guides between impeller stages that convert velocity energy to pressure energy.
• Shaft: Stainless steel 304, precision-ground, couples directly to the motor shaft.
• Suction Screen: Stainless steel 304 screen prevents sand and debris from entering the pump stages.

Stage Count Matters

The number of impeller stages inside a pump end determines how much pressure (head) the pump can generate. More stages = more pressure at the same flow rate. A 1 HP pump end designed for 5 GPM might have 23 stages, while a 1 HP pump end designed for 25 GPM might only have 7 stages. Same horsepower, completely different performance curves.

This is why you can’t just match HP to HP when replacing a pump end. You need to match the GPM code AND the HP to get the correct stage count for your application.

4. Baker 4″ Submersible Motors

Baker manufactures their own line of 4-inch stainless steel submersible motors from 1/2 HP through 5 HP in single phase, and up to 10+ HP in three phase. These motors are designed to couple with Baker pump ends using NEMA-standard motor brackets, ensuring a direct bolt-on fit without adapters.

Motor Specifications at a Glance

Motor Selection Rules

Baker designs each motor to be paired with a specific pump end HP. A 2 HP motor drives a 2 HP pump end. This 1:1 matching is non-negotiable — oversizing the motor doesn’t give you more flow, and undersizing leads to thermal overload and premature failure.

The critical takeaway: always match motor HP to pump end HP. If you need more flow, you need a higher-GPM pump end AND a matching higher-HP motor. You can’t just swap in a bigger motor on the same pump end.

5. Motor Controls — Control Boxes, Starter Kits & Pumptec

Every submersible motor needs something above ground to start it, stop it, and protect it. Baker offers three categories of motor controls depending on your motor type and protection requirements.

Control Boxes (Single-Phase, Three-Wire Motors)

If you have a three-wire single-phase motor, you need a control box. Period. The control box contains the starting capacitor (and run capacitor on larger HP) that the motor needs to start. Without it, the motor won’t turn. Baker offers two tiers:

IEC Starter Kits (Three-Phase Motors)

Three-phase motors don’t need starting capacitors — the three-phase power supply provides its own rotating magnetic field. But they still need a contactor to switch the motor on and off, and an overload relay to protect against overcurrent. Baker’s IEC Starter Kits bundle both into a pre-wired NEMA 1 enclosure:

• What’s inside: IEC-rated contactor + thermal overload relay, pre-set to the motor’s full-load amps. Factory pre-assembled.
• Voltage options: 230V, 460V, and 575V coil voltages — match to your electrical supply, not the motor voltage.
• HP range: 1/2 HP through 75 HP (460V has the widest coverage).

Pumptec Motor Protection

Pumptec is Baker’s dedicated pump protection system that goes beyond what a standard control box or starter kit provides. It monitors the motor’s actual electrical signature in real time and detects conditions that would otherwise destroy the pump or motor:

• Underload (dry run): Detects when the pump is running without water. This is the most common cause of motor burnout — the motor relies on water flowing past it for cooling.
• Overload: Detects excessive current draw from a locked rotor, worn bearings, or bound pump.
• Rapid cycling: Counts start/stop cycles and prevents the motor from restarting too quickly.
• Voltage monitoring: Detects under-voltage and over-voltage conditions from the power supply.

Pumptec installs between the control box (or starter kit) and the motor. It does not replace the control box — it supplements it. Baker offers three models: Pumptec Low (single-phase, up to 1.5 HP), Pumptec Mid (single-phase, 2–5 HP), and Pumptec Plus (single and three-phase, ½–15 HP).

6. AutoDRIVE — Variable Frequency Drive for Constant Pressure

The AutoDRIVE is Baker’s variable frequency drive (VFD) designed specifically for submersible pump applications. Instead of running your pump at full speed and cycling on/off between pressure switch set points, the AutoDRIVE continuously adjusts motor speed to maintain a constant output pressure. The result is steady, city-water-like pressure at every fixture, regardless of how many faucets, showers, or sprinkler zones are running simultaneously.

How It Works

A traditional system works like this: pressure drops below cut-in, pump kicks on at full speed, pressure builds to cut-out, pump shuts off. Repeat thousands of times per year. Each start draws 3–5× the motor’s running current, generating heat and mechanical stress.

The AutoDRIVE works differently: it continuously monitors system pressure and adjusts the motor’s operating frequency — and therefore speed — in real time. Open one faucet, the pump gently ramps to 40% speed. Open three more, it ramps to 80%. Close them all, it ramps back down and sleeps. The pressure never fluctuates more than about 1 PSI from your set point.

SD1 vs. SD3 — Two AutoDRIVE Models

Pressure Switch vs. Transducer

If you’re investing in a VFD system for constant pressure, the transducer model is the way to go. Saving a couple hundred dollars on a pressure switch when you’re already spending thousands on a VFD defeats the purpose.

7. AutoPAC — Complete Constant-Pressure Packages

The AutoPAC is Baker’s all-in-one constant-pressure package: a factory-matched submersible pump, motor, motor leads, and AutoDRIVE VFD bundled under a single part number. It eliminates the guesswork of component matching and ships ready to install.

What’s in the Box

• Baker submersible pump end — Stainless steel, sized to your GPM and HP requirements.
• Baker submersible motor — Factory-matched in your choice of 2-wire, 3-wire single phase, or 3-wire three phase.
• AutoDRIVE VFD — The correct SD1 or SD3 model for your motor configuration.
• Pressure control — Your choice of pressure switch (APS) or transducer (APT).

AutoPAC Coverage by GPM

AutoPAC vs. Buying Components Separately

8. Full System vs. Components — Decision Framework

One of the biggest decisions you’ll face is whether to buy a complete system or individual components. There’s no universal right answer — it depends on your situation.

Buy a Complete AutoPAC When…

• You’re installing a brand-new well system from scratch.
• You want constant pressure and are buying the pump, motor, and VFD at the same time.
• You want guaranteed component compatibility without cross-referencing specs.
• You want a single point of accountability for the entire system.

Buy a Standard Pump (No VFD) When…

• Your well has adequate flow and you’re satisfied with traditional pressure switch cycling.
• Budget is the primary constraint — a standard pump costs significantly less than a VFD system.
• Your application is irrigation, livestock, or other non-pressure-sensitive use.
• The installation is in a remote location where VFD electronics are hard to service.

Buy Individual Components When…

• You’re replacing a single failed component while the rest of the system is still good.
• You’re retrofitting an AutoDRIVE VFD onto an existing pump system.
• You need a non-standard combination Baker doesn’t offer as a package.
• You already have a working VFD and just need the pump and motor (order an “LB” or “LS” model).

Quick Decision Flow

9. The 12 Most Common Mistakes People Make

In our years of selling Baker systems, these are the errors we see over and over. Every one leads to wasted money, delayed installations, or premature equipment failure.

10. Frequently Asked Questions