Key Specification Ratings
Maximum Continuous Operating Voltage (MCOV) – 7.0/10
Why Did It Earn this Score? – All things considered, Leviton hasn’t gone out of their way to distinguish the 51120-1 model when it comes to MCOV. That’s because this model only provides the two basic 150 volt (L-N) and 300 volt (L-L) MCOVs that make up the current industry average. Though this average is not a negative on its own, this model’s $130+ price tag makes it almost inexcusable that Leviton would not offer more in the MCOV department. We can only hope that upcoming remakes of the Leviton 51120-1 take a positive step forward in this domain.
Voltage Protective Rating (VPR) – 9.0/10
Why Did It Earn this Score? – When we first looked over the Leviton 51120-1’s specifications, we were feeling down about the fact this model only included two VPRs. But after looking closely, our mood turned right around because the Leviton 51120-1 provides an 800 volt and 1,200 volt VPR for its L-N and L-L modes respectively. As such, homeowners with a variety of sensitive electronics can opt for the lower VPR option while homeowners with an assortment of heavy-duty electric-powered appliances can rest assured that this model’s high VPR mode will allow an ample volume of electricity through during a surge event.
Mode of Protection – 6.0/10
Why Did It Earn this Score? – If the Leviton 51120-1 has any major heel, it can be found here. That’s because the Leviton 51120-1 only provides two basic modes of protection – L-L and L-N. While these modes are very practical for use in a variety of whole home surge protection set-ups, it is still disappointing that a model that costs around $130 couldn’t offer even one more mode of protection. If you were hoping to install this model in N-G or L-G, you’ll be fresh out of luck until Leviton decides to reengineer the 51120-1 model with full functional customization in mind.
Comparing the Leviton 51120-1 and the Leviton 51110-SRG
If you stumbled upon the Leviton 51120-1 during your research to find a new whole-home surge protection option, then chances are that you also noticed the Leviton 51110-SRG. Indeed, both models even show up next to one another in a variety of online retail listings. But just how similar are these two models? Can they provide your home with an equal degree of surge protection?
First off, the Leviton 51120-1 and the Leviton 51110-SRG provide noticeably different peak surge protection ratings. Specifically, the Leviton 51120-1 provides right around 50,000 amps of protection while the Leviton 51110-SRG can only cough up around 26,000 amps of protection. While this doesn’t make the Leviton 51110-SRG an inherently worse off unit, it does mean that it can only be used safely in small homes. The Leviton 51120-1, though, can protect most mid-sized homes with ease.
The Leviton 51120-1 and the Leviton 51110-SRG also differ substantially when it comes to durability. On this front, the Leviton 51110-SRG and its NEMA 4X rated enclosure take first prize. In fact, the 4X rating is the highest an enclosure can receive under the current NEMA rating system. While the Leviton 51120-1 NEMA 1 enclosure is fairly sturdy as well, it should only be used indoors if you want it to last for its entire expected lifespan.
The Final Verdict
Even though its aggregate score isn’t stellar, the Leviton 51120-1 is still a fully worthwhile option when it comes to protecting your home from an unexpected power surge. This model provides a great capacity to protect mid-sized homes from surges of up to 50,000 amps, which more than justifies its higher-than-average price tag around $130. After factoring in this model’s use of a solid-state semiconductor and an internal DIN rail module, you can see why so many current users consider this model to be of great value.
On the downside, though, this model’s 5-year warranty has been known to give some owners a hard time. Also, this model’s use of only two modes of protection really causes it to lag behind more capable options in its price range. But those issues aside, you can certainly count on the Leviton 51120-1 to perform most, especially when it comes to protecting your whole home’s sensitive electronics.