only way to convert from 3 phase to 240 would be to change the electric motor on the compressor
Yes, if the motor is rated 240 volts 3 phase.There is such a thing as 240 volt 3 phase power.However if you are asking if you can use 240 volts single phase on a three phase motor, then the answer is no.
Amperes when kva is shown. The formula is, Amps = kva x 1000/1.73 x volts.
If you have a voltage of 127 volts to neutral (ground) then your wye connected three phase leg voltages will have to be 127 x 1.73 = 220 volts. This voltage is within the 10% allowance for voltages as should operate the compressor. As the voltage is lower that specified, the amperage rating when a reading is taken will be higher than that of the equipments nameplate.
By using a step down transformer.
500,000 watts/240 volts = 2,083.34 Amps (single phase)
If you mean by a converter, a transformer, to change the voltages then yes 240 volts can be transformed with a step down transformer from 240 volts to 208 volts in a single phase system. To answer the question single phase can not be converted to three phase without additional expensive equipment. One piece of equipment that will do it is a variable frequency drive. Another piece of equipment is a roto-phase. Either of these pieces of equipment would probably cost more than the grill you are trying to supply a voltage to.
A voltage of 240 volts is not a common three phase voltage. Single phase kva of 240 voltas and 50 amps is I x E/1000 = 240 x 50 = 12000/1000 = 12 kVa -- Assuming the 240 volts is phase to phase voltage, and this is a three phase application: KVA = V*I*sqrt (3) = 20.78KVA
For a single phase circuit, the equation you are looking for is I = W/E. Amps = Watts/Volts.
These voltages are both wye connection three phase voltages. The voltage difference comes from the primary three phase voltage supplies. 277 volts is obtained from 277 x 1.73 = 480 and 240 volts is obtained from 240 x 1.73 = 415. 480/277 volts is a common three phase American voltage. 415/240 volts is a European voltage. In Canada a common three phase voltage is 347/600. The 240 volts could also be a single phase voltage in North America derived from a split phase secondary on a distribution transformer that supplies 120/240 volts to homes.
415 V is the 'line voltage', and 240 V is the 'phase voltage' of a 415/240-V three-phase, four-wire, system. These were the standard nominal voltages used in the UK before EU 'harmonisation' forced them to be 'renamed' (but not actually changed) to '400/230 V'!! So there really isn't such a thing as separate '415-V' and '240-V' three-phase systems. And there is no economic way of changing the supply frequency to a different frequency. Incidentally, the symbol for 'hertz' is 'Hz', not 'htz'.
A three phase four wire commercial distribution service will not give you 240 volts. The nearest voltage you can get is 208 volts. It is a wye connection which gives you 208 volts between the three legs and 120 volt between any of the three legs and ground. This ground point is the systems neutral point.
Depends on where you live in the world. North America it is 120/240 volts. In new installations these days a 200 amp capacity panel is quite common.