Generators and UPS Systems – what you need to know

A lot of companies have generators that help supply power to their businesses in the event that they experience downtime. Most businesses also understand that they can get the most out of it if they connect their generator to a UPS system.


What they don’t’ know is that not all UPS systems are created differently and it’s important to choose the right system to go along with your generators. Not every system plays nice with your generator power and it’s important to know which system will work with what.


Here are the UPS systems that work well with generators and what you need to know about each of them. Let’s jump right in.


Generator and UPS System Compatibility


Generally speaking – there’s a simple rule of thumb to live by. Generators are inconsistent in the voltage they produce. What you’ll get is wide ranges in frequency where a generator is pumping out a ton of energy and then others when it’s barely producing the minimum. With this in mind – the range is wider than your UPS system is willing to accept – the load will simply run off the UPS battery until it’s gone. That’s usually how things go with your standard off-line or line-interactive UPS system.


The system we recommend – is an on-line, double conversion UPS system – as it works best with generators. The on-line UPS converts incoming AC power on a continuous basis, filters it into DC power and then reverts it back to AC power. It’s a cleaner flow of power – and one that’s safer and easier to manage for your system. Even better – on-line UPS systems filter variations in frequency, so managing the inconsistencies of a generator are part of their core function.


When size does matter


You generator should have a capacity rating that’s at least twice the rated capacity of the UPS system you’re using. When the generator is undersized, you’ll see that it will frequently cycle on and off and create inrush currents that cause the UPS to switch between AC, battery and bypass power. Just like off-line UPS systems, all that does is drain the battery life of your UPS system even more. Over-sizing the generator ensures that this doesn’t happen.


As is the case with any upgrade or install, you’ll want to make sure you have extensive conversations with your facilities managers and local electricians to make sure there aren’t any underlying safety or liability concerns. Installations need to have adequate grounding and installed up to code to minimize the risk of damage, data loss and shock hazards.


If you are looking to install a more generator-friendly UPS system, give us a call today and we’ll be happy to provide you with a free consultation. Good luck!