Modular systems by APC and Powerware allow you to easily scale, maintain, and replace your UPS as it ages. If you invest in these units, when one component goes bad, it can easily be replaced. Further if you need a larger size, you just add more modules. GreenlightUPS sells the APC Symmetra PX 40 & 80kva.
The other type of 3phase UPS is the Integral type. These units are very common and made by everyone. The most popular are the Liebert Infinity and APC Silicon. While these units can be bought used or refurbished, you take a major risk, since if one component goes bad the replacement is exorbitant. Only buy these if you have a detailed service history. These units need regular Preventive Maintenance which can be thousands of dollars each year.
So if you can afford the Symmetra PX series, we strongly recommend it over the integral units. But, if needed, we can source a well maintained integral UPS from our trusted partners. We often can find these APC Silcon 208/208v UPS units starting at $6500.00
