Voltage400 vac tolerance 320 - 450vfrequency 50hz ± 6% output voltage 400vac ± 1%power factor0.8transfer time 0 msfrequency 50hz ± 6% (on mains) 50hz ± 0.5% (on battery)waveform pure sine wavethdilinear load ≤ 3%; non-linear load ≤ 5%crest factor 3 : 1 (max)bypass facilitymaintenance bypass and static bypass dc bus / dc functions: dc bus voltage 384vcharging current 5 - 20a, adjustablecold-start functionyesbattery charging in off mode yesbattery typesealed, maintenance-free vrla LCS I user interface: metering / indications forvoltage load % frequency general status alarm communication: interfaces rs232 overload 105~125% 10 mins (output swithes to bypass after 60s) >130% 1 min environment: temperature 0 ~ 40oc humidity 20 ~ 90% non-condensingaltitude< 1000mip class20