My Trace "pure sine wave" 2.5KW 12 VDC inverter efficiency curve is very steep at low loads due to the overhead power needed just to run the unit at no load.
At first the efficiency curve rises very steeply and hits 90% at about 180 watts, tops out at 95% at 750 watts, then slowly goes downhill to about 80% at 2.5 KW, its maximum output. Ashore, the most popular DC voltage these day, from what I gather reading Home Power magazine, is 48 VDC. My isolation transformer has several taps on it to compensate for variation in line voltage. It requires only a multi position switch and no lengthy books. My inverter can also bolster up sagging line voltage to the degree of 2.5 KW, of course at the expense of battery reserves. This could come in handy for starting motors. Norm S/V Bandersnatch Lying Julington Creek 30 07.695N 081 38.484W ----- Original Message ----- From: ahmet erkan To: [EMAIL PROTECTED] Sent: 7/2/2008 9:42:03 AM Subject: (T&T: & TWL2:) Re: Inverter/isolator "Can an inverter/charger be used to isolate onboard ac from shorepower much like an isolation transformer with the benifit of being able to cary the boats ac load in the event of low dock voltage or onboard load greater than 30 amps?" IMO : The isolation transformer will perform typically at 95 to 98% efficiency compared to typically 60 to 80% efficiency of a 12V Sine wave inverter. (square wave inverters will provide better efficiency) In order to improve the efficiency of the inverter with the technology available today it is necessary to have a higher battery voltage (ie: 100Vdc) The vicissitudes (variations ?) of the power line can be corrected with a tap changing line regulator at higher efficiency and lower cost. The subject is rather lengthy and books can be written about it, however it is my belief that the bottom line described above is true for the technology available today. Best of luck Shay Ahmet SV8827
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