The ratings of ovens vary. A make and model number might get a specific set of figures. Certainly a call to the manufacturer should allow you to obtain data. Also, ovens are built with a manufacturer's plate that should have some ratings stamped on it.
Virtually nothing. The only real benefit you would get is if you had three phase vs. single phase fans, and I'm fairly certain even the three phase convection ovens use single phase fans. The oven will be rated at a certain kW usage, which applies whether it's three phase or single phase (...and will be ~ the same). If the three phase convection oven kW usage is slightly lower, it is because it is heating slightly less (so its' kW rating is actually less than the single phase), and vice versa. Insulating factors will have a significantly higher impact on cost savings compared to single vs. three phase in this instance.
Three phase ovens are made for home use. It is important however to know if the home is wired for three phase or for single phase.
The kV.A (not 'kva') rating is the total apparent power of the machine. So a 75 kV.A machine is 25 kV.A per phase.
It depends on (1) its voltage rating, and (2) whether it is single phase or three phase. And the symbol for kilovolt ampere is kV.A -not 'kva'.
No, a single-phase oven cannot be wired to a three-phase circuit without a transformer. The electrical systems are incompatible and may result in damage to the oven or the circuit. It is recommended to use the appropriate circuit or consult with a licensed electrician for proper installation.
If the phase voltage is 230 V, then (providing you are describing a three-phase, four-wire, system), then the line voltage will be 1.732 larger -i.e. 400 V.
No. You need a 3-phase supply that matches the voltage and current rating of your appliance.
All transformers, single phase or three phase have a "no-load current" rating. That is simply the nameplate rating of the Xformer in VA, (volt-amps) or KVA (1000Volt-amps) for larger Xformers. Simply divide the nameplate rating in VA or KVA by the supply voltage and you'll get the Xformers potential maximum output in ampheres.
I dont know if you can actually convert the oven's wiring from 3-phase to single phase. You can, however, convert the single phase circuit that will feed the oven to a 3-phase system. To this you will need a phase converter. Now, where to purchase such an item, and how much they cost? i have no idea.
60 amp,120/208VAC, three-phase
The primary advantage is that, for a given load, a three-phase system requires less copper for tranmission/distribution than an equivalent single-phase system would require. Other advantages include the fact that three-phase machines are smaller than single-phase machines of similar rating.
If the motor is a three phase the most likely voltage the motor operates on will be 480 volts.