Indeed, in a pinch I suppose you could put it on a rubber mat… and just make sure you yourself are on that mat when you touch it, but of course it is not ideal.
In my experience, the generators we get locally (that are not of the suitcase variety) are left floating. You can bond the neutral without any problems.
The best way to test is put an old incandescent lamp between earth and neutral. If the lamp glows (at a quarter its normal brightness), it’s V-0-V. If the lamp doesn’t glow, and there is no voltage across its terminals, then either it is already bonded, or it is floating.
That’s actually why they do this. With a V-0-V config you’re only half as far from earth, so the risks go down where this type of generator is usually used: construction sites, campsites, etc.
And leaving it floating, you need two earth faults before someone can get shocked.
I recall reading that sometimes you can easily remove the bond, since there is literally just a single point somewhere on the generator where the middle of the alternator’s windings are connected to the chassis.
Speaking of those suitcase types, which often have a plastic outer enclosure, you could probably even get away with not connecting the earth at all and just bonding one of the V-legs, since the metal parts are not exposed anyway. But those plastic-suitcase units are usually inverter units, which the Multi (or at least the ESS assistant) doesn’t like, right? I have little experience with them.
Connect a 48v PWM, PWM as there is a constant output(?) from the alternator, so no need for tracking,
Any motor that can drive the alternator at consistent revs optimal for the alternator max production … keeping the alternator as cool as possible.
EDIT: The key here, basta with off-the-shelf AC generators with issues ito interacting with i.e. ESS, go full on top quality DC generation, the key, then the actual petrol/diesel motor can be as small as you can go as long as it can drive the alternator at it’s best revs, and the PWM, connected to the Cerbo/Venus.
Technically, what you’re doing in this case is building your own inverter-generator out of parts. The alternator is of course an AC device, making wild 3-phase AC that you have to put through a rectifier bridge to get DC. Then it is turned back into AC, making the process somewhat inefficient.
You do get 48V alternators. In this application you do need to cool it sufficiently, though. There are alternators with temperature control built specifically for this implementation.
Another interesting thing to note: honda inverter generators have permanent magnet generators that also get rectified to DC before an inverter converts that to 50Hz 230VAC.
Saw that vid a while back. Stopped me dead with Lithiums in Suzi as not only is that an issue to carefully sort, she idles are like 750rpm, but the temp in the car when parked in the sun, another huge challenge to solve.
I’m just toying with an affordable solution to charge a 48v (64v max) bank using any petro/diesel engine (must smell fumes and run) to power the charging side, the charging side being totally portable/interchangeable between different engines.
EDIT: Idea is powered on the basis Eskom getting worse. So no rush today. EDIT 2: Ideal the Cerbo/Venus must be aware of the charging.
@plonkster My father actually build something like this a few years ago and still got it. He got hold of a an old army water pump motor with the frame, and added a 60amp alternator to it. He did a pully conversion so that the alternator spins at a higher rpm then the petrol motor. It runs basically a few hours on 1L of petrol. I think it will work nice with a orion-tr connected to a setup that is 12v and you don’t want a gene running.
I actually investigated gas (LPG) powered generators before Covid hit for our callcenter. The physical logistics made it very difficult to handle diesel, but LPG was already being piped and billed for a couple of restaurants in the building.
Looked like a very good option. Quiet (er) too.
Not exactly cheap, but that’s a real standby generator, not a construction one. And again, the storage requirements for gas is a lot better than diesel.
You should be able to convert almost any petrol generator to LPG - the same way people have done the conversion on cars so that they don’t have to pay the additional road taxes on petrol.
