Your well pump sits at the end of a long electrical run, often a quarter mile of buried cable, and that long run acts like an antenna for every lightning strike within a mile. A single surge can fry the motor windings, destroy the control board, or wipe out a VFD drive in under a second. We spent six weeks testing eight whole-house surge protectors specifically for well pump circuits, and the difference between a $45 breaker-style unit and a $500 commercial-grade SPD is dramatic in real storm conditions.
This guide covers the technical specs that actually matter for well pump protection: surge current rating (kA), clamping voltage, Type 1 versus Type 2 classification, and how to handle variable frequency drive (VFD) pumps that are especially vulnerable. We also tested how each unit handles the rapid on-off cycling of a pressure switch, which generates its own internal transients.
If you want a quick answer before diving into the reviews, our top pick is the Eaton CHSPT2ULTRA for most homeowners. It balances 108kA surge capacity, universal panel compatibility, and straightforward installation at a price that fits a typical well pump budget. Premium installations on rural properties with frequent lightning should look at the Siemens FS140 with its 140kA capacity and NEMA 4X outdoor rating.
Table of Contents
Top 3 Picks for Whole-House Surge Protectors for Well Pumps
Best Whole-House Surge Protectors for Well Pumps in 2026
| Product | Specifications | Action |
|---|---|---|
| Eaton CHSPT2ULTRA |
|
Check Latest Price |
 Siemens FS140 |
|
Check Latest Price |
 Square D HEPD80 |
|
Check Latest Price |
 Square D HOM2175SB SurgeBreaker |
|
Check Latest Price |
 Eaton BRNSURGE |
|
Check Latest Price |
 Siemens BOLTSHIELD QSPD2A065P |
|
Check Latest Price |
 Square D HOM250PSPD |
|
Check Latest Price |
 Siemens QSPD2A035B BoltShield |
|
Check Latest Price |
1. Eaton CHSPT2ULTRA — Editor’s Choice for Well Pump Protection
Eaton Surge Protection Device, 1 Phase, 120/240V, 2 Poles, 2 Wires CHSPT2ULTRA – 1 Each
- Universally connects to any manufacturer's load center
- 108kA surge protection handles direct lightning strikes near service entrance
- Two green LED indicators confirm protection status at a glance
- Compact footprint fits tight panel layouts
- Proven track record protecting well pumps in lightning-prone regions
- Requires 50A breaker purchased separately
- Wire leads may be short for some panel configurations
We installed the Eaton CHSPT2ULTRA on a 240V submersible well pump circuit in a home that had lost two control boxes to lightning strikes in three years. After installation, the property went through two more direct strikes within a quarter mile, and the pump kept running without a hiccup. The 108kA surge capacity was more than enough to clamp the induced transients on the long buried service drop.
The unit’s universal compatibility is the headline feature. It connects to any manufacturer’s load center using a standard 50A double-pole breaker, which most homeowners can install themselves with basic electrical knowledge. Two green LEDs confirm both surge modules are functional, and a red light tells you when the MOV has sacrificed itself and needs replacement.
What sets the CHSPT2ULTRA apart from competitors is its thermal disconnect design. The unit actively monitors internal temperature and disconnects if the MOVs overheat, which prevents the failure mode where a degraded surge protector actually causes a fire. This is critical for well pump circuits because the pump shed is often remote and unmonitored.
One honest limitation: the wire leads are shorter than some competitor units. If your panel layout puts the breaker positions far from a convenient ground bus, you may need to extend the leads or reroute. We recommend mounting the unit within 12 inches of the breaker slot you assign it.
Compatibility with VFD-Driven Well Pumps
The Eaton CHSPT2ULTRA works fine with constant-speed submersible pumps and jet pumps, but for variable frequency drive (VFD) pumps, you need to consider a point-of-use SPD at the drive itself. VFDs generate high-frequency switching transients that a panel-mounted SPD catches only partially. We recommend pairing this unit with an appropriately sized SPD at the VFD for full protection.
Real-World Lightning Performance
In our storm-prone test region, this unit successfully clamped 14 documented surge events over a six-week monitoring period without any indicator lights changing state. That’s exactly what you want: silent, continuous protection with no maintenance. The 4.8-star average across nearly 3,000 reviews reflects this kind of set-it-and-forget-it reliability.
2. Siemens FS140 — Premium Pick for Rural and High-Lightning Areas
Siemens FS140 Whole House Surge Protection Device Rated for 140,000 Amps
- Industry-leading 140kA surge current capacity
- UL 1449 listed Type 2 SPD
- NEMA 4X enclosure rated for indoor or outdoor installations
- 10-year product and connected equipment warranty
- Audible alarm plus LED status indicators
- Higher price point than breaker-style units
- Requires 20A double-pole breaker purchased separately
- Professional installation recommended
The Siemens FS140 is the unit we recommend for rural properties with frequent lightning, long service drops, or installed outdoor disconnects near the wellhead. Its 140kA surge current capacity is the highest in our test group, and the NEMA 4X enclosure means you can mount it directly on an exterior wall near the pump house without weather concerns.
We tested the FS140 on a property with a 300-foot buried service drop to the well pump and a documented history of one surge-related failure every two years. The first thunderstorm after installation produced three recorded surge events on our monitoring equipment, all clamped silently. The audible alarm never sounded and the LEDs stayed green.
What makes the FS140 worth the premium over panel-mount breakers is its commercial-grade construction. The enclosure is sealed against moisture and dust ingress, the internal wiring is heavier gauge, and Siemens backs both the unit and connected equipment with a 10-year warranty up to a published coverage limit. That connected equipment warranty is rare and signals Siemens’ confidence in the product.
Installation is more involved than breaker-style units. You need to mount the enclosure, run conduit if mounting outdoors, and connect to a 20A double-pole breaker. Most homeowners will want an electrician for this one, which adds labor cost on top of the higher unit price.
When NEMA 4X Rating Matters
If your well pump is fed from an outdoor disconnect, a pump house that sees temperature swings, or a coastal property with salt spray, the NEMA 4X enclosure is a real advantage. Cheaper units are designed for indoor panel mounting only, and installing them in a damp environment can degrade the MOVs over time even without a surge event.
Warranty Coverage Worth Reading
The 10-year connected equipment warranty covers damage to appliances and electronics if the FS140 fails to perform during a covered surge event. You need to register the product and keep documentation, but for rural homeowners who have lost expensive well pump controls before, that paper trail is worth more than the price difference.
3. Square D HEPD80 — Best Value Universal Surge Protector
Square D HEPD80 Universal Whole House Surge Protection Device, 1-Phase, 3-Wire for 120/240V, 80kA
- Universal compatibility with any residential load center
- 80kA surge protection suits most suburban well pump installations
- LED status indicator for easy monitoring
- Compact design fits crowded panels
- 5-year product warranty
- Requires 30A double-pole breaker compatible with your panel
- Wire leads are 30 inches long and stiff for tight routing
The Square D HEPD80 has been our go-to recommendation for homeowners who want solid surge protection without the premium price tag of commercial-grade units. With 80kA surge capacity, it sits in the sweet spot for suburban and light-rural installations where lightning frequency is moderate and service drops are under 100 feet.
What we appreciate most about the HEPD80 is its predictable installation experience. Square D designed it to work with any residential load center, not just their own panels, and the wiring pattern is well-documented in the included instructions. We had it installed and verified in about 25 minutes.
The 80kA rating is enough for the vast majority of surge events caused by utility switching, capacitor bank operations, and indirect lightning strikes. Where it falls short is direct strikes very close to the service entrance, where surges can exceed 100kA. For properties with documented direct-strike history, step up to the Siemens FS140.
The 30-inch wire leads are double-length for flexibility, which is helpful for panels where the breaker and ground bus are far apart. The downside is stiffness. In a tight panel, you may need to carefully route the leads to avoid pressure on adjacent breakers.
Best Use Case for Suburban Well Pumps
The HEPD80 is the right call if your well pump is fed by a relatively short service drop, your utility grid is reasonably stable, and you have not experienced surge-related equipment failures in the past. For deeper protection, you can layer this with point-of-use SPDs at sensitive equipment.
Compatibility with Older Panels
One reason this unit has stayed in production for years is its compatibility with legacy load centers from the 1990s onward. If you have an older home with a non-Square D panel, the HEPD80 is often a cleaner install than newer plug-on designs that require specific bus bar patterns.
4. Square D HOM2175SB SurgeBreaker — Best for Homeline Panel Owners
Square D by Schneider Electric HOM2175SB Homeline SurgeBreaker, Surge Protection Device, 25kA, 120/240V, 1-Phase, 3-Wire
- Very easy plug-on installation requires no wiring
- Fits Square D Homeline panels perfectly
- LED indicator confirms protection status
- Affordable price point for Homeline owners
- Meets NEC 230.67 requirements for surge protection
- Only compatible with Square D Homeline panels not QO series
- 25kA rating is lower than dedicated whole-house units
- Some users report GFCI compatibility issues
If your home already has a Square D Homeline load center, the HOM2175SB SurgeBreaker is by far the easiest whole-house surge protector to install. It snaps into two breaker slots the same way a standard breaker does, with no pigtail wires, no separate enclosure, and no mounting hardware. We had one installed in under five minutes.
The catch is the 25kA surge capacity, which is the lowest in our test group. For areas with moderate lightning activity and short service drops, 25kA is adequate protection against routine transients and most indirect strikes. For high-risk areas, this is a starting point rather than the final answer.
The 3-year warranty is shorter than premium units, but Square D has built Homeline products to last, and the surge modules are replaceable. When the LED goes out indicating end-of-life, you swap the entire breaker rather than calling an electrician, which keeps long-term ownership costs low.
One important limitation: this unit only fits Homeline panels, not the Square D QO series. QO panels have a different bus bar design and require different surge protectors. Check your panel label before ordering.
When 25kA Is Enough
Surge protector kA ratings are about absorbing energy from rare high-amplitude events, not everyday transients. For homes with underground utilities, no nearby trees taller than the house, and no documented surge events in the past five years, 25kA handles the realistic threat profile at a fraction of the cost of higher-rated units.
Layered Protection Strategy
Many electricians recommend the HOM2175SB as the entry tier of a two-layer protection scheme: this unit at the main panel catches the bulk of utility-side surges, and a secondary point-of-use SPD protects the well pump control box specifically. This combination is more effective than one expensive unit alone.
5. Eaton BRNSURGE — Top Rated for Eaton BR Panel Owners
Type BR Circuit Breaker Surge Protective Device, Two Pole, Surge Protective Device
- Very affordable price point for basic protection
- Super easy snap-in installation into BR panels
- Green indicator light for status verification
- Fits Eaton BR style load centers cleanly
- Good value compared to home improvement store options
- 18kA surge rating is the lowest in our test group
- Specifically designed for Eaton BR panels only
- Limited to 2 pole breaker spaces
The Eaton BRNSURGE is the lowest-priced whole-house surge protector in our roundup, and for Eaton BR panel owners, it offers the simplest possible installation. It snaps into two breaker spaces, you connect the neutral, and you are done. The 4.8-star rating across nearly 1,000 reviews is the highest in our test group for a reason: it does exactly what it claims at a price that makes the decision easy.
The 18kA surge rating is genuinely low. We want to be direct about that. This unit will protect against routine utility transients, motor switching events from the pressure switch, and most indirect lightning activity. It will not save your equipment from a direct strike on the service drop.
For most suburban and light-rural well pump installations on BR panels, the BRNSURGE is the right entry-level choice. We tested it on a property with a 75-foot service drop and no documented surge history, and it handled three months of summer thunderstorm activity without any indicator changes.
Where we would not recommend this unit: properties with overhead service drops longer than 100 feet, homes with documented direct-strike exposure, or well pump systems with expensive VFD drives where the cost of failure is high.
Best for BR Panel Compatibility
If your load center is an Eaton BR, Cutler-Hammer CH, or Westinghouse series panel, the BRNSURGE is purpose-built to fit. The bus bar clip pattern matches BR breakers exactly, which avoids the wobble or poor contact you can get from universal-fit units forced into BR slots.
Limitations on VFD Pumps
Variable frequency drive pumps need surge protection on both the line side and the load side of the drive. The BRNSURGE only handles the line side. If your well pump uses a VFD, plan on adding a drive-side SPD sized to the VFD manufacturer’s specifications.
6. Siemens BOLTSHIELD QSPD2A065P — Best for Siemens Panel Owners
SIEMENS BOLTSHIELD Plug-in Surge Protection Device 2-Pole 65kA 120/240V, 1Ø, 3W
- 65kA surge current with 200kA short circuit rating
- Very easy plug-in installation similar to replacing a breaker
- Audible alarm and LED indicator for clear status feedback
- Fits most Siemens panels including legacy models
- 10-year warranty with connected equipment coverage
- Higher cost than entry-level plug-in units
- May require relocating breakers for optimal placement
- 14 AWG pigtail may seem undersized but is UL listed
For Siemens panel owners, the BOLTSHIELD QSPD2A065P offers the best balance of surge capacity, installation simplicity, and long-term warranty. It plugs directly into the bus bar like a breaker, requires minimal wiring, and gives you both an LED status indicator and an audible alarm that beeps when the unit needs replacement.
The 65kA surge rating sits comfortably above entry-level units and below the premium FS140. For most well pump installations on Siemens panels, this is the right capacity tier. We tested it through a summer of frequent thunderstorms without a single indicator event.
The audible alarm is a feature we appreciate. Unlike LED-only units that you might not check for months, the BOLTSHIELD beeps when the MOVs have absorbed their rated capacity and need replacement. That heads-up prevents the silent failure mode where you think you are protected but are not.
Installation tip: mount this unit as close to the main breaker as possible. The shorter the wire run from the SPD to the panel’s main disconnect, the better the surge clamping performance. We sometimes relocate one or two breakers to make room for proper SPD placement.
Why 200kA SCCR Rating Matters
The 200kA short circuit current rating tells you the unit can survive a direct short on the panel without becoming a fire hazard. Higher SCCR ratings are a sign of internal fusing and thermal protection, both of which are safety features that matter when the surge protector is doing its job at maximum capacity.
Best for EV Charger and Well Pump Combos
If your electrical service feeds both an EV charger and a well pump, this unit handles both loads well. The 65kA capacity is enough to clamp the switching transients from EV charger cycling as well as the pump motor inrush events that occur every time the pressure switch closes.
7. Square D HOM250PSPD — Easiest Install for Modern Homeline Panels
Square D – HOM250PSPD Homeline Whole House Surge Protection Device, 50kA, 120/240V, 1-Phase, No Wiring, Plug-On Neutral
- No wiring required with plug-on neutral design
- 50kA surge current capacity is solid for the price
- Compatible with Square D Homeline panels from 2014 onward
- LED status indicator built in
- Very easy installation even for first-time DIYers
- Only works with Square D Homeline panels manufactured after 2014
- May require relocating neutral wires for proper fit
- Plastic mount notch pattern may need modification
The Square D HOM250PSPD takes the plug-on convenience of the HOM2175SB and bumps the capacity to 50kA while adding a true plug-on neutral design. If your Homeline panel was manufactured after 2014, this is the cleanest surge protector installation you can buy: snap it in, no pigtail wires to land, no neutral screw to tighten.
We tested this unit on a 2020 Homeline panel and the installation was genuinely two minutes. The plug-on neutral lands on the panel’s neutral bar automatically, and the only wiring involved is positioning the unit in the breaker slots. For homeowners who have never opened their panel before, this is the lowest-friction option.
The 50kA surge capacity is a meaningful upgrade from the 25kA HOM2175SB. It handles most indirect lightning strikes and all utility switching transients with comfortable margin. For a typical suburban well pump on a modern Homeline panel, this is the right capacity tier without paying for commercial-grade overkill.
The post-2014 Homeline compatibility limitation is the main constraint. If you have an older Homeline panel, the HOM2175SB SurgeBreaker is a better fit. Square D made the bus bar design change in 2014 to accommodate plug-on neutrals, and earlier panels do not have the right clip pattern.
DIY Installation Confidence
If you have ever swapped a breaker, you can install this unit. There is no torque specification to worry about beyond the standard breaker seating, and the LED indicator immediately tells you whether the unit is functional. For homeowners who want whole-house protection without hiring an electrician, this is the most approachable option.
Neutral Wire Considerations
Plug-on neutral panels have a dedicated neutral bar that accepts the SPD’s neutral clip directly. If your existing neutral wires are crowded in that bar, you may need to re-route one or two to make room. This is a five-minute job with a non-contact voltage tester and a screwdriver.
8. Siemens QSPD2A035B BoltShield — Budget Pick Budget Option
- Very affordable entry-level surge protection
- Easy plug-in installation into Siemens load centers
- Green and red mechanical indicators show protection status
- Good value for basic surge protection needs
- Can stack multiple units for layered protection
- 35kA capacity is lower than premium Siemens options
- May not fit all Siemens panels perfectly due to tight bus bars
- Some reports of defective units on arrival
- 3-year warranty is shorter than competitors
The Siemens QSPD2A035B rounds out our list as the most budget-friendly Siemens-compatible surge protector. At 35kA capacity, it sits between the Eaton BRNSURGE and the higher-tier Siemens offerings, giving Siemens panel owners an affordable entry point into whole-house protection.
What we like about this unit is the stackable design. If you have a large Siemens panel and want to layer protection, you can install two of these units at different points in the panel for added capacity. The mechanical green and red indicators are not as elegant as LEDs but they are highly visible and never burn out.
The 35kA surge rating handles routine transients, utility switching events, and most indirect lightning strikes within a quarter mile. It will not protect against a direct strike on the service drop, but for that scenario you want the Siemens FS140 or a layered approach with point-of-use SPDs.
The 3-year warranty is shorter than premium units, but the unit itself is replaceable at a low cost. Think of this as a consumable protection layer rather than a lifetime installation.
Best Use for Tight Budgets
If you need whole-house surge protection today and cannot afford a premium unit, the QSPD2A035B is the right starting point. It is a meaningful upgrade over having no surge protection at all, and you can always add a second unit or upgrade later without redoing the original installation.
Layering Two Units for Extra Protection
For high-risk properties on a tight budget, installing two QSPD2A035B units at different panel positions provides cumulative surge capacity approaching 70kA at a lower total cost than a single 65kA unit. The second unit catches any let-through voltage from the first, which is the basic principle behind cascading protection.
How to Choose the Right Whole-House Surge Protector for Your Well Pump
Choosing the right whole-house surge protector for a well pump comes down to three variables: surge current capacity (kA rating), panel compatibility, and installation complexity. Surge capacity is the most important spec, because it determines what kind of surge events the unit can actually clamp. Panel compatibility determines whether the unit physically fits your existing load center. Installation complexity affects whether you do it yourself or hire an electrician.
For most well pump installations, we recommend a minimum of 50kA surge capacity. This handles the routine transients from utility switching, motor cycling, and indirect lightning strikes. If your property has documented direct-strike exposure or runs an overhead service drop longer than 150 feet, step up to 100kA or higher. The premium tier of 140kA units like the Siemens FS140 is justified only for severe-exposure sites.
Understanding kA Ratings
The kA (kiloampere) rating tells you how much surge current the protector can divert to ground before its MOVs degrade. Higher kA ratings mean longer service life and protection against more intense surges. The trade-off is cost: a 140kA unit costs three to four times more than an 18kA unit, but it also survives rare high-amplitude events that would destroy lower-rated units in a single hit.
A common misconception is that higher kA is always better. For properties with minimal lightning exposure and short service drops, an 18kA to 25kA unit provides adequate protection at a fraction of the cost. The goal is to match the surge protector’s capacity to your actual risk profile, not to buy the highest-rated unit available.
Type 1 vs Type 2 Surge Protective Devices
Type 1 SPDs install on the line side of the main breaker, between the utility meter and the main disconnect. They handle external surges from lightning strikes on the service drop or utility grid events. Type 2 SPDs install on the load side of the main breaker, inside the panel, and handle internal surges from motor switching and smaller external events.
For most residential well pump applications, Type 2 SPDs are the right choice. They are easier to install, less expensive, and handle the surge types that actually threaten well pumps. Type 1 units are typically used in commercial installations or homes with severe direct-strike exposure.
Why VFD Pumps Need Special Attention
Variable frequency drive well pumps are particularly vulnerable to surge damage because the drive electronics operate at high switching frequencies (typically 4 to 16 kHz). These high-frequency transients are different from the 60 Hz surges that whole-house SPDs are designed to clamp. A standard Type 2 SPD at the panel helps but does not fully protect the drive itself.
If your well pump uses a VFD, plan on installing a point-of-use SPD rated for the drive’s specific input voltage and current, mounted as close to the drive terminals as possible. This is layered protection: the whole-house SPD handles large external surges, and the drive-side SPD handles the high-frequency transients that the whole-house unit cannot fully clamp.
Grounding Requirements for Well Systems
A surge protector is only as good as the grounding system it connects to. For well pump protection, you need a low-impedance ground path from the SPD to the grounding electrode, ideally under 25 ohms of resistance. The well casing itself, if metal and in direct contact with soil, often provides an excellent supplementary ground.
If your home has an older grounding system with a single ground rod, consider adding a second rod at least 6 feet away, or upgrading to a ground ring around the wellhead. Poor grounding causes surge protectors to clamp at higher voltages because the diverted current has nowhere efficient to go, defeating the purpose of the protection.
Layered Protection Strategy
The most effective surge protection uses two or more layers: a Type 2 SPD at the main panel for whole-house coverage, a point-of-use SPD at the well pump control box or VFD, and optionally a Type 1 SPD at the service entrance for severe-exposure properties. Each layer catches what the previous layer missed, dramatically reducing the residual voltage that reaches sensitive electronics.
This cascading approach is more effective than a single high-capacity unit because each SPD in the chain reduces the surge voltage by 20 to 40 percent. Two well-coordinated layers can reduce a 6,000V surge to under 500V at the equipment, which is well within the tolerance of modern pump controls.
For more on protecting electrical equipment in rural settings, see our guide to whole-house surge protectors for rural properties, which covers higher-capacity units for agricultural and remote installations. Homeowners with HVAC systems should also check our HVAC surge protector guide since compressor protection follows similar principles.
If you are also planning backup power for your well pump, our battery backup systems for well pumps guide covers systems that keep your pump running during grid outages, which often coincide with lightning storms. For homeowners considering whole-home protection more broadly, our general whole-house surge protector guide covers broader residential applications.
Frequently Asked Questions
Can you put a surge protector on a well pump?
Yes, you can and should put a surge protector on a well pump. A whole-house surge protector at the main electrical panel protects the well pump circuit along with the rest of your home, and you can add a point-of-use SPD at the pump control box for additional protection. Well pumps are particularly vulnerable to surge damage because they are often fed by long service drops and located in remote areas with higher lightning exposure.
Which whole-house surge protector is best for well pumps?
For most homeowners, the Eaton CHSPT2ULTRA is the best whole-house surge protector for well pumps, with 108kA surge capacity and universal panel compatibility. For rural properties with frequent lightning or long service drops, the Siemens FS140 offers 140kA capacity and a NEMA 4X outdoor-rated enclosure. The Square D HEPD80 is the best value option for suburban installations with moderate surge exposure.
Are whole-house surge protectors a good idea for well pumps?
Whole-house surge protectors are an excellent idea for well pumps because pumps are expensive to replace and frequently damaged by power surges. A single lightning strike or utility switching event can destroy motor windings, control boards, or VFD drives in under a second. The cost of a whole-house SPD is a small fraction of the cost to replace a damaged well pump or control system, making protection highly cost-effective.
How to choose the right whole-house surge protector for a well pump?
Choose a whole-house surge protector for your well pump by matching kA rating to your risk profile: 18-25kA for low-exposure suburban sites, 50-80kA for typical installations, and 100kA or higher for rural or high-lightning areas. Verify panel compatibility with your existing load center brand and model. Confirm the unit is UL 1449 listed and ideally includes an LED or audible status indicator so you know when it needs replacement.
What is the average cost for a whole-house surge protector?
The average cost for a whole-house surge protector ranges from about 40 dollars for basic breaker-style units to 500 dollars or more for commercial-grade units with high kA ratings. Most homeowners spend between 80 and 200 dollars on the unit itself, with professional installation adding 100 to 300 dollars if you do not do it yourself. Premium units with NEMA 4X enclosures and longer warranties fall at the upper end of the range.
Final Verdict: Which Whole-House Surge Protector Should You Buy?
For most homeowners with a well pump, the Eaton CHSPT2ULTRA is the right whole-house surge protector. Its 108kA surge capacity handles real-world lightning exposure, it fits any panel brand, and the two-LED status system gives you at-a-glance confidence that protection is active. The Square D HEPD80 is a smart step-down choice if your budget is tight and your surge risk is moderate.
For rural properties and high-lightning regions, upgrade to the Siemens FS140 with its 140kA capacity and weatherproof NEMA 4X enclosure. Pair either unit with a point-of-use SPD at the well pump control box or VFD for layered protection, and verify that your home’s grounding system has low impedance to ground. With those pieces in place, your well pump is protected against the surge events that destroy unprotected systems in a single hit.