120/240 Volt Panel Protector, 4-Mode Protection, Light Commercial/Residential Grade, In NEMA 1 Enclosure, 51120-1

Although I am a graduate electrical engineer and formerly a licensed electrician, installing this Leviton 51120-1 120/240 Volt Panel Protector and connecting it to my modern Leviton electric panel was no small project. Without such a background, a do-it-yourself homeowner might be prudent to hire an electrician. To gain access to one of my main panel's knock-outs, so I could install a 1/2" X 3 1/2" conduit nipple between the two, I used a hole saw to create an opening through a wooden stud. That required a right angle drill because a conventional drill would not fit into the 6" square opening required for the Panel Protector. The knock out on the electric panel, of course, needed to be exactly aligned with the knockout on the panel protector. Careful measurements are important. Installing the conduit nipple between the two metal cabinets, required lock nuts and bushings on each end before threading the wire. Using metal conduit between my panel and this device helps to enhance ground continuity in addition to the green grounding wire. The extra grounding should improve protection. Instructions with this surge protection unit suggests connecting it to the panel through a two-pole 20-amp or 30-amp circuit breaker. My choice was a 30-amp breaker which calls for #10 copper wire. I used THNN wire for the connections, which included L1 & L2 hot wires, a white neutral and a green grounding wire. A DEWALT Impact ready right angle attachment to my impact tool enabled me to use screws to mount and secure the panel protector to the wooden stud. Turning on the breaker illuminated the two green lights on this device showing that it is actively protecting. I'm optimistic that this surge protection will be effective for our home, which has had some power surge issues in the past. The photo shows my modern Leviton panel with the Leviton surge protection unit to the right.

A power surge on the incoming utility line consists of a very short duration high voltage Spike. For about three to seven milliseconds the line voltage will rise by several hundred volts. Voltage is like the water pressure in a hose, current is like the water itself. When voltage spikes, it's driving the current through the circuit at extremely high pressure, so to speak. The voltage Spike will damage digital equipment. Most manufacturers warranties, especially those of internet capable digital appliances do not cover voltage spikes. In addition to this product which should be installed by a licensed electrician, I also purchased 20 amp surge protected Outlets for each of my new appliances. The outlets are available on Amazon for about $23 each. They install like any normal outlet would, but contain surge protection built into the outlet. Having the whole house surge protector and individual outlets at the appliance locations gives me great peace of mind that my appliances are safe from voltage spikes. It will also protect your big screen 4K TV and the audio system that goes with it, along with your computer system and any laptops or cell phones that are plugged into wall Chargers or Outlets. This product does not require a permit to be installed at your panel board. But please, unless you are a trained electrician, do not attempt to install it yourself. Most electricians will charge $150 to $250 to install it. Given the low cost of the surge protector itself I consider an investment of less than $500 to be a great insurance policy that you'll never have to pay another premium on.

Easy installation (inside wall). Looks beautiful!

...knowing that my house is protected from power surges. I did some research before buying the Leviton protector. It is more expensive than some others, but it has the highest specification I found for any protector for single phase residential use. For a long time I have had plugin UPSs or protected power strips for sensitive electronics, but now I live in a place prone to power irregularities. My local power utility will install a whole house protector for a cost of $10 per month added to the electric bill. At that rate the Leviton protector will pay for itself in about 18 months. I am happy to have installed this unit to protect the rest of my electrical devices and appliances from surges. I especially like the indicator lights that show that the suppressor is in good working order. It was a breeze to install; it took me less than 30 minutes from power cut to power restore, and that includes time for opening the panel knockouts and mounting the Leviton protector to the wall. If you are comfortable working around electricity you can quite easily do this yourself. You can find detailed installation instructions on the Leviton website if you need to assess the complexity of installing before buying. Just note that this protector does not come with the four wires required to connect it to the main panel. It needs two black wires (one for each of the two hot electric busses), one white one (for the neutral connection) and one green (for the ground connection). You can use any cable or wires with a minimum of 12 gauge if connected to a 20 amp breaker. I used an offset nipple between the panel and the protector, and this worked very well for my situation as my electrical panel is surface mounted, not recessed.

Being an Inside Journeyman Wireman made the install easier. Installed this in my house. I had to go to HD for some parts once. Namely a right angle drill attachment so I could drill into the side of the panel via the 6x6" cutout. I didn't want to cut a bigger hole and have to patch the wall. Sturdy enclosure. The directions for install list the knockouts as 3/4"...they are 1/2" and I noticed it right away. Overall it's a nice device. Time will tell if it does what it says it will.

WORKS AS PROMISED

Just had it installed but have had no hits yet.

For the $300 dollars I believe every house should have one. Install was straight forward and it is very well made.

Great outside of the panel mounted surge protector.

Easy to install.