A whole-home surge protector (SPD) mounts at your electrical panel and clamps voltage spikes before they reach the circuits that feed your HVAC, appliances, and electronics. It is sized to your panel, installed in under an hour in most homes, and it costs far less than replacing a single fried control board.
What it is and where it goes
The device connects to a 2-pole breaker (or two open spaces) in your main panel and to the panel’s neutral and ground. When a spike hits — lightning on the utility lines, grid switching, or a big motor cycling inside the house — it diverts the excess energy to ground in a fraction of a microsecond. Short, straight leads matter, so we mount it as close to the breaker as the panel allows.
Matching the protector to your panel size
Your panel’s amperage tells us a lot about the house behind it — how many large loads, how much electronics, and how the service is fed. Here’s how we typically match the surge protector:
| Panel size | Typical home | What we install |
|---|---|---|
| 100A | Older or smaller homes, few 240V loads | Type 2 SPD, moderate kA rating; older panels often need two spaces freed up first |
| 150A – 200A | Most Triangle and Triad homes: heat pump, range, dryer, water heater | Type 2 SPD with a higher kA rating, mounted on a 2-pole breaker in the main panel |
| 200A + subpanel | Garage, basement, ADU, or shop subpanel | SPD at the main panel; a second unit at a distant subpanel feeding sensitive equipment |
| 320A / 400A | Large homes, EV chargers, pool, two 200A panels | SPD at each panel, or one Type 1 unit at the meter-main — highest kA rating |
We also check the panel’s grounding and bonding before we install. A surge protector with a poor ground path has nowhere to send the energy — see our guide to electrical panel grounding.
How it protects the panel, appliances, and electronics
- The panel itself. AFCI, GFCI, and smart breakers contain electronics. A surge protector shields them from the same spikes that cook other circuit boards.
- HVAC and heat pumps. Control boards and variable-speed motors are among the most expensive parts in the house to replace after a surge.
- Kitchen and laundry appliances. Refrigerators, ranges, dishwashers, washers, and dryers all run on control boards now.
- Electronics. TVs, computers, routers, security systems, and smart-home hubs — everything on every circuit, not just what’s plugged into a strip.
- EV chargers and generators. Expensive equipment wired straight to the panel, with no power strip in the path.
- Surges from inside the house. Many spikes start at home when large motors cycle on and off. Small, repeated hits wear electronics down over time; the panel unit absorbs them before they add up.
One visit, one dispatch fee
We charge a dispatch fee for every visit, and it’s per visit — not per item. That makes a surge protector one of the easiest add-ons you can make: book it with work you already need and it’s parts and a short install on the same trip, instead of a separate visit and a second dispatch fee later.
- Panel upgrade — code requires it on a new or replaced service, so it’s built into the job.
- EV charger install — protect the charger and the car’s onboard electronics on the same visit.
- Generator hookup — add it while the panel is already open.
- Repair or troubleshooting call — ask the tech while they’re at the panel.
- Protection plan inspection — members can add it during their scheduled safety visit.
Compare that with the other side of the math: after a surge, you may be paying separate service calls to an HVAC company, an appliance repair tech, and an electrician — each with its own trip charge, plus the parts.
Common questions
Is a whole-home surge protector required?
On new services and whenever a service is replaced or upgraded, the NEC now requires a surge protective device for homes. On an existing panel that isn't being changed, it's optional — but it's one of the cheapest protective upgrades you can make.
Does my panel size change the surge protector?
Yes. The device has to be rated for your panel's voltage and fault current, it needs two open spaces or a dedicated 2-pole breaker, and larger homes with more motors, electronics, and a longer service drop benefit from a higher surge-current (kA) rating. A 400A home with two panels usually gets protection at each panel or one Type 1 unit at the meter-main.
What if my panel is full?
We can often free two spaces with approved tandem breakers or by consolidating circuits. If the panel is at the end of its life, we'll price a panel upgrade and the surge protector together so you only pay for one trip.
Does it replace my power strips?
No. The panel unit takes the big hit at the service entrance; point-of-use strips mop up what's left for TVs, computers, and gaming gear. The two work as layers.
How long does it last?
Surge protectors sacrifice themselves absorbing energy. We install units with a status light — when the light changes, it has done its job and should be replaced.
How long does installation take?
Usually under an hour on a panel with open spaces. Power to the house is off briefly while we connect it.
Is there a dispatch fee for a surge protector install?
Yes — every visit carries our standard dispatch fee (protection plan members get their plan’s dispatch benefit). The fee is per visit, not per item, so adding a surge protector to a visit you’re already booking — a panel upgrade, EV charger, generator hookup, or repair call — means you pay one dispatch fee instead of booking a separate trip later.