Brian, The way the generators usually are set up is an transfer switch at the input of the UPS. When commercial power is lost the ATS signals the Genset to start and once the input voltage stablizes the UPS shuts down. This scenario assumes the use of a line interactive UPS which includes the UPS you describe. In the case of a online the UPS "sees" that line power has been restored. When power is restored the ATS switches back to commercial power and signals the generator to shut down. The ATS usually "exercises" the generator as well on a set schedule as well. My advice is to contact a local electrician who specializes in generator installations as local codes define what you are allowed to do. BTW APC has an environmental monitor card with relay outputs which can be used to start a compatible generator. once again you need to talk to your local electrician. Scott C. McGrath On Mon, 29 Mar 2004, Brian (nanog-list) wrote:
Does anyone know of a way to get a UPS to trigger a generator to start, and to switch over to the generator power automatically or does this type of thing just not exist?
Right now we've got a APC Symmetra UPS at 12kva, with no generator. The UPS keeps us running for about 45 minutes, which just isn't enough time. I called APC, but they didn't seem to have any type of automatic solution. Their method is to hook it up to a switch, and manually change the feed to the UPS from the building power to the generator power and back, but it sure would be nice to have something more automated (to save me from running like a madman when the UPS page wakes me up at 4am).
I'd be very grateful to hear of any solutions that you guys have come up with in this arena. Also, any recommendations for generators? I'm not looking for something huge, just something that can be mounted on a roof. If I have to pour diesel into it every couple hours, that's fine too.
Thanks in advance, Brian