The practice of daisy-chaining electrical devices, or plugging one power device into another, is tempting because it feels like a way to get more protection. In the case of a UPS, however, plugging it into a power bar or a separate surge protector is not recommended. Why is this problematic?
Firstly, redundancy is not always beneficial when it comes to electrical protection. Both UPS systems and surge protectors use similar mechanisms, often Metal Oxide Varistors (MOVs), to guard against voltage spikes. By connecting a UPS to a surge protector, you create a redundant layer that might cause one or the other to respond slower than if it were acting on its own. In scenarios of rapid voltage fluctuations, you want the quickest possible response, and an unnecessary middleman can inhibit that.
Moreover, many surge protectors and power bars have a maximum power rating. A UPS, especially when supporting multiple devices during a power outage, can draw power that exceeds this rating, potentially leading to overheating, failure, or a meltdown of the surge protector. This not only jeopardizes the safety of connected equipment but can also pose a fire risk in extreme cases. Lastly, some UPS systems actively monitor the quality of their power source. By introducing another device in the chain, you might trigger false alarms or cause the UPS to switch to battery mode unnecessarily due to perceived inconsistencies in the power source.
In conclusion, while the idea of combining multiple protective devices feels intuitive, it’s essential to remember that each is engineered for a specific scenario. Plugging a UPS into another protective device can inadvertently create complications, reducing efficacy and introducing risks. Don’t daisy chain UPSs, don’t plug a UPS into a surge protection, or a power bar. Don’t do it. For optimal performance and safety, a UPS should always be connected directly to a wall outlet.