Some Manufacturers Say Yes

Popular electric device manufacturers like Eaton and Alltec Global say you can plug a UPS into a surge protector. In fact, they recommend it. While that sounds contrary to popular opinion, their reasons make a lot of sense.

UPSes are known primarily as battery backups, but they also contain some form of built-in surge protection ability to meet the IEEE Standard, which states that networked surge protection devices (SPDs) are needed for UPS battery backups. So that should mean that a UPS is enough for your devices, right? Well, not quite.

According to Eaton, the level of surge protection provided by most UPSes is second-rate at best and should never be considered the primary surge protection device. But even if you took manufacturer claims at face value, most don’t even give enough values—let through voltages, joule rating, etc.—for you to assess the adequacy of this built-in surge protection.

The overarching idea is that a surge protector will safeguard your equipment and even the connected UPS from high voltage spikes. Just make sure never to exceed the maximum load of either strip (UPS or surge protector).

Others Advise Against It

Manufacturers like APC and Australian company UPS Solutions do not recommend plugging a UPS into a surge protector. So what are their reasons?

For starters, UPS Solutions mentions there’s nothing wrong with plugging a surge protector into a UPS if done correctly. However, UPS Solutions kicks against it for reasons you may have heard before, such as the UPS switching to battery power even without a grid failure due to uneven power distribution among its outlets—this will result in faster battery wear. However, this problem will likely only occur when heavy appliances are connected to the surge protector’s extra outlets.

Other reasons pointed out include the power strip potentially overloading the UPS and subsequently increasing the chances of a power spike. It also might just void your warranty. APC highlights similar reasons but says that your warranty and Equipment Protection Policy will be maintained only if you use an APC brand surge protector with your APC brand UPS.

Should You or Should You Not?

So with those seemingly conflicting views in mind, are you safe to plug your surge protector into your UPS? Ultimately, the answer depends on the specific UPS and surge protector you have and what the manufacturer has to say about it.

To be on the safe side, check the user manual and warranty of your device for more information on the dos and don’ts of that particular model. If your manufacturer doesn’t provide answers and you decide to plug your UPS into your surge protector anyway, you should at least avoid connecting appliances that demand a lot of power. You might also consider buying UPSes and surge protectors from manufacturers that do give you specific answers, since that signals better customer support that won’t leave you in the dark.