Generator earthing

Assuming the tractor is powerful enough, >100 HP, then you could probably blow a 200A fuse with this arrangement sometime in the future. Again we seem not to appreciate that the current available from Generators is not like a mains supply, it is strictly limited both mechanically and electrically. Overload is not the major problem with this kind of installation, the alternator could probably not melt a 70mm cable whatever you did in the way of drive power. The windings are forced air-cooled and really quite thin, but overload will usually slow the motive power significantly, and this will usually trip the AVR and so remove the output almost completely long before you damage anything. If you have enough engine to spin an 80kVA alternator at full speed at say twice full loading (meaning something like 220HP, you need a JCB modern fastrack) you might then pop a 200A fuse. In fact, you are likely to damage the drive gearbox first going from 540/1000 RPM to 1500 for the alternator. Remember too that the design is such that producing the correct output voltage is fine but making 1-2 volts at several hundred amps from the windings is another thing altogether, as there is a huge magnetic field problem with a very low load impedance and the reactance will go through the roof, also limiting the current. You do not need an overload fuse / CB, and too much load will simply not work as you imagine. Reading your last post, you do have an alternator with the correct ratio gearbox don't you, because if not you have no electrical problems at all! Note too that a tractor will only produce maximum power at the rated PTO speed, it needs to be right and is always marked on the rev counter.

Assuming the tractor is powerful enough, >100 HP, then you could probably blow a 200A fuse with this arrangement sometime in the future. Again we seem not to appreciate that the current available from Generators is not like a mains supply, it is strictly limited both mechanically and electrically. Overload is not the major problem with this kind of installation, the alternator could probably not melt a 70mm cable whatever you did in the way of drive power. The windings are forced air-cooled and really quite thin, but overload will usually slow the motive power significantly, and this will usually trip the AVR and so remove the output almost completely long before you damage anything. If you have enough engine to spin an 80kVA alternator at full speed at say twice full loading (meaning something like 220HP, you need a JCB modern fastrack) you might then pop a 200A fuse. In fact, you are likely to damage the drive gearbox first going from 540/1000 RPM to 1500 for the alternator. Remember too that the design is such that producing the correct output voltage is fine but making 1-2 volts at several hundred amps from the windings is another thing altogether, as there is a huge magnetic field problem with a very low load impedance and the reactance will go through the roof, also limiting the current. You do not need an overload fuse / CB, and too much load will simply not work as you imagine. Reading your last post, you do have an alternator with the correct ratio gearbox don't you, because if not you have no electrical problems at all! Note too that a tractor will only produce maximum power at the rated PTO speed, it needs to be right and is always marked on the rev counter.