Ring Voltage on ShoreTel ST48A voice switch

[jwjames]

Recently installed a ShoreTel Phone system in my company. We utilize a lot of analog phone extensions across a wide campus. When we installed the ST48A voice switch, we were assured the analog ring voltage of these switches was 90 volts. We are having issues ringing phones, took a voltage measurement and are only seeing 48 volts.. I can't seem to find the analog line specs anywhere on the web that I as a consumer have access to. Does anyone know what the analog ring voltage should be on these appliances. We were led to believe that there was a version that used the 48 volt ring voltage, but that ShoreTel upgraded their switches to the higher voltage.

Does anyone have any true facts about what the ring voltage SHOULD BE?

Thanks!