I will check to see if my OBi110 has the relay. My concern regarding electricity is not about power to the phone. My understanding is that VOIP e911 calls are transmitted over the internet. Perhaps I am mistaken. If a fire or flood caused disruption of power across a wide area, call termination would not be resolved by my UPS. I realize a land line could also be rendered inoperable, but not as likely as electric power.