Generator voltage: 220 or 230

[MapisM]

I would have sweared that my generator used to give a 230V output.
This year, I've just noticed that it gives 220V, pretty constant regardless of load, and everything seem just fine, other than this difference...
Wadduthink, should I worry?
And if yes, for my generator or for my memory...?
It's an Onan, fwiw.

 

[jfm]

I would have sweared that my generator used to give a 230V output.
This year, I've just noticed that it gives 220V, pretty constant regardless of load, and everything seem just fine, other than this difference...
Wadduthink, should I worry?
And if yes, for my generator or for my memory...?
It's an Onan, fwiw.

When I was at Fairline factory last week they said they set the generators at 230v, as if they had a choice. I noted this and went to the Onan website and it turns out they (mine are model MDKBT) are installer selectable between 220, 230 or 240v. With correspondingly falling amps of course, so the KVA output stays basically the same.

I don't know how exactly you make the voltage selection during installation. The install manuals are not downloadable and I don't have a paper Onan install manual currently because I just sold my boat. But maybe you were sleepwalking one day and changed yours from 230 to 220?

I wouldn't want 220v. Any resistive items wouldn't work well. The toaster would make lousy toast, especially

 

[petem]

I believe that the standard voltage across Europe (inc UK) is now 230v with appliances (inc JFM's toaster) required to work with a tolerance of +/- 10% (i.e. 207-253v). The standard for some European countries was 220v (and was 240v for UK).

Pete

 

[MapisM]

it turns out they ... are installer selectable between 220, 230 or 240v

Many thanks J, I would have never thought they are.
I just had a look at the installation manual of mine (a MDKD, much older than yours).
According to it, there's a trimmer which as I understand allows a fine regulation, not just 3 preset voltage.
Tomorrow I'll have a look, toasts were not bad at all so far, anyway...
Thanks again.

 

[MapisM]

And the plot thickens...

When I turned on the genny this morning, the voltage was back to 230!?!
This time I kept an eye on the voltage, and discovered that it slowly falls from 230 to 220 (where it stabilizes), in 10 minutes or so.
In other words, it looks like it works at 230 when cold. Most likely, it's always been like that, and I just never noticed.
But, can anyone see a reason? I could only imagine that it's meant to reduce the load on the diesel engine while cold, but why should a higher V as such reduce the engine load?!?

PS: Yeah, I know, RTFM might be the answer. But laziness aside, I've only got the paper ones, which are awful for any kind of search...

 

[jfm]

When I turned on the genny this morning, the voltage was back to 230!?!
This time I kept an eye on the voltage, and discovered that it slowly falls from 230 to 220 (where it stabilizes), in 10 minutes or so.
In other words, it looks like it works at 230 when cold. Most likely, it's always been like that, and I just never noticed.
But, can anyone see a reason? I could only imagine that it's meant to reduce the load on the diesel engine while cold, but why should a higher V as such reduce the engine load?!?

PS: Yeah, I know, RTFM might be the answer. But laziness aside, I've only got the paper ones, which are awful for any kind of search...

That's weird. Higher voltage doesn't reduce the load, and anyway 5% is neither here nor there in terms of load. I can't begin to guess why a genset would be 230v initially then fall to 220v.

 

[MapisM]

Any Onan expert around

That's weird. Higher voltage doesn't reduce the load, and anyway 5% is neither here nor there in terms of load. I can't begin to guess why a genset would be 230v initially then fall to 220v.

Yep, weird indeed. I can't get my head around it too.
I had a look at the manual in the meantime, it doesn't seem to say anything about it.
Besides, today I checked it again, and it's 230V only upon a really cold start.
If restarted after just one hour or so from the previous run, it gives 220V immediately...

 

[grumpy_o_g]

The only thing I can suggest is what are you measuring the voltage across? It's a long shot but is something between the field windings and the point you're measuring at causing a volt drop? It does sound a bit like something is starting to break down when it gets a bit warm.

 

[MapisM]

Thanks g_o_g, I see what yoy mean.
It's difficult to trace the wires from the genset to the electrical panel, though. I've got a V and an A meter on it, that's where I'm taking my readings from.
There's one thing which leads me to think that this shouldn't be the problem, though: these days, I'm not running the A/C, which is what need more current. Therefore, I'm never using a lot of Amps, typically just 6 to 8.
When the A/C is running, the A absorption is much higher, but the genset never missed a beat...