I am an electronics tech but I fill an electrician's position at a VA hospital. It's a long story why this VA does not use real electricians but that's another thread. Recently an HVAC system has started tripping a 70 amp breaker (3ph, 460V) (elevator also on the circuit). The breaker is located in one building and feeds another building 330 ft away. I've corrected some of the issues and reduced the nuisance tripping to an "acceptable" level (not acceptable to me but the bosses have quit complaining). One of the issues was the panel room was so hot in the area of the breaker (rated 104F but the breaker temp was 110F). That was corrected by adjusting the room's ventilation, the breaker is now at about 95F but I've since learned that other devices were added to the circuit before I came to work here that were never recorded, I just stumbled across them. So now I'm thinking that the 70 amp breaker is no longer adequate and the breaker and wiring should be for 150 amps. I'm basing that on measuring continuous power at 47 amps and non continuous at 91 amps ((47x1.25)+91)). Is this correct?
Like I said I'm an electronics tech, not an electrician, but I'm all they have right now. There is no funding available to have a contractor come in and deal with this right now, that may be a year away and the affected building is the OI&T building with the medical servers in it. Now I understand the physics of the issue but I'm not so strong on the code and the required calculations. So, the existing wire size is 2 awg with THW insulation (330ft). The current breaker is a 70 amp CH FS340070A. Can I go to a 90 or 100 amp breaker with what I described or am I heading down the wrong road?
Like I said I'm an electronics tech, not an electrician, but I'm all they have right now. There is no funding available to have a contractor come in and deal with this right now, that may be a year away and the affected building is the OI&T building with the medical servers in it. Now I understand the physics of the issue but I'm not so strong on the code and the required calculations. So, the existing wire size is 2 awg with THW insulation (330ft). The current breaker is a 70 amp CH FS340070A. Can I go to a 90 or 100 amp breaker with what I described or am I heading down the wrong road?