Residential · Franklin County & St. Louis, MO
Missouri thunderstorms, downed lines, and Ameren grid switching all send voltage spikes into your home — and a single surge can fry HVAC boards, refrigerators, EV chargers, and every piece of electronics on the circuit. A whole-home surge protector mounts at your panel and clamps those spikes before they reach anything inside. CAS Electric installs Type 2 SPDs across Franklin County and the Greater St. Louis area — Pacific, Washington, Union, Sullivan, St. Clair, Eureka, Wildwood, Villa Ridge, and Marthasville — usually in under an hour.
Modern homes are packed with electronics that hate voltage spikes: HVAC control boards, refrigerator inverters, EV chargers, smart thermostats, LED drivers, garage door openers, and every screen in the house. A whole-home surge protector (SPD) is the single most cost-effective piece of insurance you can put on your panel.
The way it works is simple. When voltage on your incoming service spikes above safe levels — typically from a nearby lightning strike, a downed line, or Ameren switching a grid segment — the SPD short-circuits the excess to ground before it reaches your branch circuits. It happens in nanoseconds and you don't feel a thing.
We install Type 2 SPDs from Eaton, Siemens, Square D, and Leviton, matched to your panel brand. Most installs take under an hour, cost a fraction of what a single HVAC control board replacement costs, and carry a manufacturer warranty on connected equipment.
Whole-home surge protector pricing depends on the SPD model and panel brand. We provide a free written estimate before starting. Devices typically carry a 5–25 year warranty plus a connected-equipment warranty from the manufacturer.
We look at your panel brand, available breaker space, and grounding to pick the right Type 2 SPD for your home.
You get a written price for the device + install — no hourly meter running.
We mount the SPD next to your main breaker, land it on a dedicated 2-pole breaker, verify grounding, and test the status indicator.
We show you the status LEDs, explain what to do if it ever trips, and leave you with the warranty paperwork.
Cost depends on the SPD model and your panel brand. Our install covers a quality Type 2 SPD, a dedicated 2-pole breaker, and the labor to mount and wire it at your main panel. We give a free flat written estimate before starting.
Yes — for layered protection. The whole-home unit clamps the big spikes at the panel, but sensitive electronics (TVs, computers, gaming consoles) benefit from a point-of-use surge strip as a second line of defense.
No device stops a direct strike to your home — that's why you carry homeowner's insurance. What a whole-home SPD does stop is the much more common stuff: nearby lightning that induces a surge on the lines, downed-line events, and Ameren grid-switching transients.
Most quality SPDs last 5–10 years under normal grid conditions, longer if your area doesn't see heavy storms. Every unit we install has status LEDs — when they change color, it's time to replace the device.
Not usually. As long as you have two adjacent breaker slots open and your panel is in good shape, we can add a Type 2 SPD. If your panel is full or a problem brand (Federal Pacific, Zinsco), we'll talk through whether a panel upgrade makes sense first.
Licensed, insured, owner-operated. We respond to all estimates within 1 business day.