Easy enough to figure how long it will take. 1 BTU is equivalent to 1055 joules and will raise one pound of water 1 °F. As a watt is 1 joule/sec, 2755W is 2755/1055 = 2.61 BTU/sec or 156.7 BTU/min. You have 30L of water weighing 66 lbs, Thus it will take 66/156.7 = 0.42 minutes to raise the temperature 1 °F. From 72° to 212°F is 140° and it would thus take 59 minutes to raise 30L of water from room temperature to boiling. This asumes no losses through the vessel or the surface of the water. There is actually quite a bit of loss through the surface so times will be noticeably longer if you don't cover the pot (and preferrably, insulate it e.g. by putting a throw pillow on it).

It's also pretty easy to calculate the amount of water vaporized in a certain time interval once boiling starts. The heat of vaporization for water is 2260 kilojoules per kilogram. 2755 watts is 2.755 kJ/sec so it will take 2260/2.755 = 820 seconds (14 minutes) to boil off a kg (~ 1L) of water.