Franklin Electric Motors and Control Boxes

Franklin Electric builds the submersible motors under a large share of the pumps in Henderson County wells, and its control boxes are the single most commonly replaced part in this trade after the pressure switch. That is good news for homeowners: a $200 to $450 control box is very often the whole repair on a pump that hums and will not start, and no pump comes out of the ground to fix it. The diagnostic that separates a box from a motor is $150 to $300.

What Franklin Electric makes

Franklin’s water line is built around submersible motors in 4, 6, 8, 10, and 12 inch diameters, plus 8 by 6 inch models, with standard encapsulated versions along with high-efficiency MagForce, high-temperature, dual-voltage, and dual-rated variants. Residential wells here run on the 4-inch line almost without exception.

The 4-inch encapsulated motor spans 1/3 through 10 horsepower, in single-phase 115 and 230 volt versions at 60 Hz and a range of three-phase voltages. Franklin lists both 2-wire and 3-wire configurations. Construction is hermetically sealed and water-lubricated, with a stainless steel splined shaft, a Kingsbury-type thrust bearing, and a pressure-equalizing diaphragm. Franklin also lists corrosion-resistant construction, an anti-track self-healing resin system, a filter check valve on water well models, built-in lightning arrestors on single-phase motors, a sand-fighter slinger, and NSF/ANSI 61 certification for drinking water, with 316 stainless steel and other application-specific options.

Two of those details matter directly in this county. Lightning arrestors on single-phase motors matter because rural feeders in the Blue Ridge take surges town circuits never see, and a summer storm around Dana or Edneyville produces a cluster of dead control gear the next morning. And NSF/ANSI 61 certification matters because everything wetted in a drinking water well should be, which is one of the things to check when someone offers a bargain pump.

2-wire versus 3-wire, and why you care

A submersible needs starting components. Where they sit is the whole difference.

• 2-wire motors carry the starting switch and capacitor inside the motor itself. Two conductors plus ground run down the well, nothing hangs on the wall, and there is nothing at the surface to fail. The trade is that if the starting components do fail, the motor comes out of the well.
• 3-wire motors put the start capacitor and relay in a control box mounted near the pressure tank. Three conductors plus ground run down the well. That box is exposed to heat, cold, and surges, so it fails more often, but replacing it costs $200 to $450 and takes an hour, with the pump untouched.

Neither is better in the abstract. What is bad is a technician who does not know which one is in front of him, because on a 3-wire system the control box is the first thing to test and on a 2-wire system there is nothing to test at the surface at all.

The QD control box

Franklin’s QD, or quick disconnect, boxes serve Franklin 3-wire single-phase motors from 1/3 through 1 horsepower, which covers most residential wells in this county. They use Franklin’s own QD relay with a capacitor-start design, and the components disconnect automatically when the lid is removed, which is what makes troubleshooting one quick and safe. Franklin lists the 60 Hz models as UL listed for the United States and Canada. There is also a CRC variant that adds a run capacitor for smoother motor operation in the 1/2 through 1 horsepower range.

Two field notes. First, the horsepower on the box has to match the motor. A 1/2 horsepower box on a 3/4 horsepower motor will not start it reliably, and the mismatch shows up as intermittent humming that gets blamed on the pump. Second, a box that failed once is worth a second look at the motor: a motor dragging on a worn bearing pulls a start capacitor’s life down fast, so a careful tech reads amps against the nameplate in the same visit rather than fitting a box and driving away.

What a proper diagnosis looks like

Before anything is condemned, we take four readings, and all four are cheap:

1. Voltage at the pressure switch and at the control box, under load.
2. Capacitor and relay test in the box on a 3-wire system.
3. Winding resistance across each pair of pump leads, compared against the manufacturer’s table for that motor and horsepower.
4. Insulation resistance from each lead to ground.

Balanced windings that match the table, with high resistance to ground, mean the motor is healthy and the fault is at the surface or in the wire. A low reading to ground means current is leaking, and then the question is motor or drop wire: a wire chafed against steel casing over twenty years looks identical from the breaker panel and nothing like it on a meter. That distinction is worth $400 to $1,500 for a wire repair against $1,200 to $3,500 for a pump, which is the whole reason the tripping breaker page exists.

What it costs

All from the pricing page. You can price your own case with the no water diagnostic estimator.

Where Franklin fits against the other brands

Franklin makes motors, and other companies build pump ends onto them, so a Franklin motor may sit under a Goulds or a Pentair Sta-Rite pump end. That is normal and it is not a compromise. The alternative approach is a pump with the electronics carried inside it, like the Grundfos SQ, which removes the control box from the equation entirely. Both are sound. What decides the outcome is not the badge but whether the pump was sized to the well’s depth and yield and whether the pressure tank beside it is doing its job, and both of those are covered on the replacement page.